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Introduction Up to 5% of patients with a solid malignant tumor are admitted to an intensive care unit (ICU) within 2 years of diagnosis, with most receiving organ support during their stay.1 Most of these patients are admitted from a surgical specialty unit, often at the time of surgical intervention for their cancer. As the incidence of cancer continues to rise,2 it seems likely that the number of patients with cancer who are considered for intensive care will also increase. There is some evidence that decisions to admit patients with cancer are influenced by assumptions about poor prognoses, with cancer being the second most common cause cited for ICU refusal.3,4 As outcomes in patients with cancer continue to improve, these assumptions may not be valid.5 A systematic review illustrated that variations in ICU mortality among patients with cancer were largely attributable to differences between study populations’ severity of illness, type of admission, performance status, and need for organ support rather than the presence of cancer.6

these assumptions may not be valid.5 A systematic review illustrated that variations in ICU mortality among patients with cancer were largely attributable to differences between study populations’ severity of illness, type of admission, performance status, and need for organ support rather than the presence of cancer.6 A limitation of many previously published studies has been that they do not include a comparison group of patients without cancer; thus, it is difficult to determine the effect of cancer within the same ICU setting.7 Taccone et al8 described the outcomes of all patients with cancer admitted to 198 European ICUs in 2002 and found that survival of patients with solid tumors was similar to that of ICU patients without cancer. More recently, a series of articles by Bos and colleagues9,10,11 detailed outcomes in general ICUs for patients with cancer in the Netherlands. They found that, while unplanned surgical ICU admission was associated with similar ICU mortality in patients with and without cancer, in-hospital mortality after ICU admission was higher for surgical patients with cancer than for those without cancer, at 17.4% compared with 14.6%.10 Considering the limited information on the comparative outcomes of patients with and without cancer admitted to general ICUs published to date, we sought to describe the characteristics and outcomes of surgical patients with solid malignant tumors following ICU admission.

A limitation of many previously published studies has been that they do not include a comparison group of patients without cancer; thus, it is difficult to determine the effect of cancer within the same ICU setting.7 Taccone et al8 described the outcomes of all patients with cancer admitted to 198 European ICUs in 2002 and found that survival of patients with solid tumors was similar to that of ICU patients without cancer. More recently, a series of articles by Bos and colleagues9,10,11 detailed outcomes in general ICUs for patients with cancer in the Netherlands. They found that, while unplanned surgical ICU admission was associated with similar ICU mortality in patients with and without cancer, in-hospital mortality after ICU admission was higher for surgical patients with cancer than for those without cancer, at 17.4% compared with 14.6%.10 Considering the limited information on the comparative outcomes of patients with and without cancer admitted to general ICUs published to date, we sought to describe the characteristics and outcomes of surgical patients with solid malignant tumors following ICU admission. Methods Data Sources and Variables This was a retrospective observational study of patients living in the West of Scotland region aged 16 years or older who were admitted to a general ICU located in the region between January 1, 2000, and December 31, 2011. Within the United Kingdom, ICU physicians have full admitting rights, although the ICU and surgical team share patient care. Full details are described elsewhere.1 Patients admitted from a surgical specialty at admission to the ICU were selected based on the admitting specialty recorded in the ICU database. Patients with cancer were identified as having a diagnosis of a solid malignant tumor on the Scottish Cancer Registry between January 1, 2000, and December 31, 2009. We compared these patients with cancer and surgical patients admitted to the ICU between January 1, 2000, and December 31, 2011, who did not have a preceding diagnosis of cancer on the Scottish Cancer Registry. Data analysis was conducted between January 1, 2000, and December 31, 2011, for ICU admission and January 1, 2000, and December 31, 2009, for the Scottish Cancer Registry.

dmitted to the ICU between January 1, 2000, and December 31, 2011, who did not have a preceding diagnosis of cancer on the Scottish Cancer Registry. Data analysis was conducted between January 1, 2000, and December 31, 2011, for ICU admission and January 1, 2000, and December 31, 2009, for the Scottish Cancer Registry. This study was approved by the West of Scotland Research and Ethics Committee. Approvals to use the data were obtained from the West of Scotland Critical Care Research Network, Scottish Intensive Care Society Audit Group, and the West of Scotland Cancer Surveillance Unit. Patient identifiers were made available to the research group, but the analysis for this study was performed on an anonymized data set. Ethical review concluded that no additional patient consent would be required owing to the nature of the study. The study used 4 linked data sets: the Scottish Cancer Registry, Scottish Morbidity Record 01, national death records, and the Scottish Intensive Care Society Audit Group WardWatcher ICU database. WardWatcher collects data on patient demographics, admitting specialty, admission diagnosis, the Acute Physiology and Chronic Health Evaluation (APACHE) II scoring system,12 and type of organ support. Organ support was defined as receipt of invasive mechanical ventilation, vasoactive drugs to provide cardiovascular support, or renal replacement therapy.

t demographics, admitting specialty, admission diagnosis, the Acute Physiology and Chronic Health Evaluation (APACHE) II scoring system,12 and type of organ support. Organ support was defined as receipt of invasive mechanical ventilation, vasoactive drugs to provide cardiovascular support, or renal replacement therapy. All surgical patients in the ICU database were included in the analysis. We used death and hospital discharge records to identify whether patients died during their hospital stay. Intensive care unit stays could not be matched to a hospital discharge summary for 649 of 25 017 patients (2.6%). For these patients, hospital discharge date and status were retrieved from the WardWatcher data set. The nature of hospital admission was unknown for these patients and they were excluded from analysis of admission type (emergency vs elective). APACHE II scores were not recorded for 5732 patients (22.9%), and the proportion of patients with missing scores was described for both groups. For calculation of the numbers of organs supported, patients were categorized as not having received support for an organ with missing data.

All surgical patients in the ICU database were included in the analysis. We used death and hospital discharge records to identify whether patients died during their hospital stay. Intensive care unit stays could not be matched to a hospital discharge summary for 649 of 25 017 patients (2.6%). For these patients, hospital discharge date and status were retrieved from the WardWatcher data set. The nature of hospital admission was unknown for these patients and they were excluded from analysis of admission type (emergency vs elective). APACHE II scores were not recorded for 5732 patients (22.9%), and the proportion of patients with missing scores was described for both groups. For calculation of the numbers of organs supported, patients were categorized as not having received support for an organ with missing data. Statistical Analysis Median and interquartile ranges (IQRs) were used to summarize continuous variables, and Wilcoxon rank sum test was applied to determine differences in median values. Pearson χ2 test and exact 95% CIs were used to compare proportions. Odds ratios (ORs) for hospital mortality were calculated for the presence of cancer, age 65 years or older, emergency hospitalization, direct admission from the surgical theater, reason for ICU admission, APACHE II score of 20 or higher (higher scores indicate increased severity of illness and corresponding mortality), and year of group’s ICU admission. A multivariate model was then constructed using factors with significance at P < .05, determined using 2-tailed, paired testing on univariate analysis with the exception of reason for ICU admission documented as malignancy, because this diagnosis had colinearity with the presence of cancer.

ar of group’s ICU admission. A multivariate model was then constructed using factors with significance at P < .05, determined using 2-tailed, paired testing on univariate analysis with the exception of reason for ICU admission documented as malignancy, because this diagnosis had colinearity with the presence of cancer. All patients were included in survival analysis. A time-varying covariate indicated the period in ICU, the stay in the hospital following discharge from the ICU, and the period following hospital discharge. Kaplan-Meier curves and log-rank test were used to compare survival between the cancer and noncancer group. Statistical analyses were performed using Stata, version 14.0 (StataCorp). Results During the study period, there were 25 017 surgical patients admitted to general ICUs in the West of Scotland, of whom 13 694 (54.7%) were male. The median age was 64 years (IQR, 50-74), and 5462 (21.8%) had an underlying solid tumor diagnosis. Table 1 gives patient characteristics for surgical admissions to ICU with and without a diagnosis of cancer.

re 25 017 surgical patients admitted to general ICUs in the West of Scotland, of whom 13 694 (54.7%) were male. The median age was 64 years (IQR, 50-74), and 5462 (21.8%) had an underlying solid tumor diagnosis. Table 1 gives patient characteristics for surgical admissions to ICU with and without a diagnosis of cancer. Table 1. Surgical Admissions to ICU in Patients With and Without Cancera Variable All Patients Patients Who Received Organ Support Noncancer (n = 19 555) Cancer (n = 5462) P Value Noncancer (n = 13 046) Cancer (n = 3165) P Value Men, No. (% [95% CI]) 10 696 (54.7 [54.0-55.4]) 3201 (58.6 [57.3-59.9]) <.001 7312 (56.0 [55.2-56.9]) 1941 (61.3 [59.6-63.0]) <.001 Median age (IQR), y 62 (45-74) 68 (60-76) <.001 63 (46-74) 68 (60-76) <.001 Emergency hospitalization, No./total No. (% [95% CI]) 15 255/18 979 (80.2 [79.6-80.8]) 2128/5389 (39.5 [38.2-40.8]) <.001 10 892/12 680 (85.9 [85.3- 86.5]) 1299/3128 (41.5 [39.8-43.3]) <.001 Admitted from surgical theater, No. (% [95% CI]) 12 026 (61.5 [60.8-62.2]) 4375 (80.1 [79.1-81.2]) <.001 7436 (57.0 [56.2-57.9]) 2329 (73.6 [72.1-75.2]) <.001 Reason for admission, No. (%) Malignancy 244 (1.2) 2294 (42.0) <.001 80 (0.6) 961 (30.4) <.001 GI/liver 4778 (24.4) 1020 (18.7) 2624 (20.1) 555 (17.5) Sepsis 3089 (15.8) 610 (11.2) 2949 (22.6) 540 (17.1) Surgical complication 893 (4.6) 376 (6.9) 689 (5.3) 297 (9.4) Respiratory disorder 1174 (6.0) 244 (4.5) 863 (6.6) 198 (6.3) Hemorrhage 1377 (7.0) 206 (3.8) 992 (7.6) 168 (5.3) Vascular 2392 (12.2) 56 (1.0) 1368 (10.5) 31 (1.0) Trauma 1702 (8.7) 30 (0.6) 1103 (8.5) 18 (0.6) Cardiovascular 769 (3.9) 180 (3.3) 393 (3.0) 99 (3.1) Renal disorder 308 (1.6) 84 (1.5) 794 (6.1) 33 (1.0) APACHE II score, median (IQR) 17 (12-22) 17 (13-21) .12 18 (14-24) 18 (14-23) .18 Not recorded, No. (%) 4073 (20.8) 1659 (30.4) <.001 1040 (8.0) 293 (9.3) .02 Respiratory support, No./total No. (% [95% CI]) 12 300/19 220 (64.0 [63.3-64.7]) 2919/5306 (55.0 [53.7-56.4]) <.001 12 300 (94.3 [93.9-94.7]) 2919 (92.2 [91.2-93.1]) <.001 Unknown, No. (%) 335 (1.7) 156 (2.9) <0.001 1 0 .62 Cardiovascular support, No./total No. (% [95% CI]) 7103/19 080 (37.2 [36.4 -37.9]) 1584/5291 (29.9 [28.7-31.2]) <.001 7103 (54.4 [53.7-55.4]) 1584 (50.0 [48.4-51.9]) <.001 Unknown, No. (%) 475 (2.4) 171 (3.1) .004 33 (0.3) 4 (0.1) .18 Renal support, No./total No. (% [95% CI]) 1557/16 882 (9.2 [8.8-9.7]) 237/4674 (5.1 [4.5-5.7]) <.001 1557 (13.3 [12.7-14.0]) 237 (8.3 [7.3-9.3]) <.001 Unknown, No.

.9]) 1584/5291 (29.9 [28.7-31.2]) <.001 7103 (54.4 [53.7-55.4]) 1584 (50.0 [48.4-51.9]) <.001 Unknown, No. (%) 475 (2.4) 171 (3.1) .004 33 (0.3) 4 (0.1) .18 Renal support, No./total No. (% [95% CI]) 1557/16 882 (9.2 [8.8-9.7]) 237/4674 (5.1 [4.5-5.7]) <.001 1557 (13.3 [12.7-14.0]) 237 (8.3 [7.3-9.3]) <.001 Unknown, No. (%) 2673 (13.7) 788 (14.4) .15 1365 (10.5) 301 (9.5) Organ support, No. (%) 0 6186 (31.6) 2146 (39.3) <.001 0 0 <.001 1 6438 (32.9) 1779 (32.6) 6438 (49.3) 1779 (56.2) 2 5302 (27.1) 1197 (21.9) 5302 (40.6) 1197 (37.8) 3 1306 (6.7) 189 (3.5) 1306 (10.0) 189 (6.0) Unknown for all modes 323 (1.7) 151 (2.8) <.001 0 0 ICU mortality, No. (% [95% CI]) 3295 (16.8 [16.3-17.4]) 666 (12.2 [11.3-13.1]) <.001 3066 (23.5 [22.8-24.2]) 588 (18.6 [17.2-19.9]) <.001 Hospital mortality, No. (% [95% CI]) 5490 (28.1 [27.4-28.7]) 1252 (22.9 [21.8-24.1]) <.001 4693 (36.0 [35.1-36.8]) 993 (31.4 [29.8-22.0]) <.001 Abbreviations: APACHE, Acute Physiology and Chronic Health Evaluation (higher scores indicate increased severity of illness and corresponding mortality); ICU, intensive care unit; IQR, interquartile range. a Numbers are cumulative total.

(%) 2673 (13.7) 788 (14.4) .15 1365 (10.5) 301 (9.5) Organ support, No. (%) 0 6186 (31.6) 2146 (39.3) <.001 0 0 <.001 1 6438 (32.9) 1779 (32.6) 6438 (49.3) 1779 (56.2) 2 5302 (27.1) 1197 (21.9) 5302 (40.6) 1197 (37.8) 3 1306 (6.7) 189 (3.5) 1306 (10.0) 189 (6.0) Unknown for all modes 323 (1.7) 151 (2.8) <.001 0 0 ICU mortality, No. (% [95% CI]) 3295 (16.8 [16.3-17.4]) 666 (12.2 [11.3-13.1]) <.001 3066 (23.5 [22.8-24.2]) 588 (18.6 [17.2-19.9]) <.001 Hospital mortality, No. (% [95% CI]) 5490 (28.1 [27.4-28.7]) 1252 (22.9 [21.8-24.1]) <.001 4693 (36.0 [35.1-36.8]) 993 (31.4 [29.8-22.0]) <.001 Abbreviations: APACHE, Acute Physiology and Chronic Health Evaluation (higher scores indicate increased severity of illness and corresponding mortality); ICU, intensive care unit; IQR, interquartile range. a Numbers are cumulative total. Intensive care unit patients with cancer tended to be older than patients without cancer with median (IQR) age 68 (60-76) vs 62 (45-74) years (P < .001). Most of the population without cancer had been admitted to hospital as an emergency (15 255 of 18 979 patients [80.2%]) in contrast to only 39.5% (2128 of 5389 patients) of the population with cancer. Admission to ICU directly from the surgical theater was more common in the cancer group (80.1% [4375 of 5462 patients] vs 61.5% [12 026 of 19 555 patients]; P < .001). Intensive care unit admission was related to an underlying solid tumor for 2294 (42.0%) of the cancer group. The most frequent diagnostic groups were otherwise similar between the cancer and noncancer groups with sepsis, gastrointestinal/ liver disease and surgical complications as common causes for admission. Vascular disease and trauma occurred more frequently in the noncancer group.

or for 2294 (42.0%) of the cancer group. The most frequent diagnostic groups were otherwise similar between the cancer and noncancer groups with sepsis, gastrointestinal/ liver disease and surgical complications as common causes for admission. Vascular disease and trauma occurred more frequently in the noncancer group. The APACHE II score was available for 15 482 (79.2%) of patients without cancer and 3803 (69.6%) of patients with cancer with similar median (IQR) values for both groups (17 [12-22] vs 17 [13-21]), P = .12). Organ support was provided less frequently in the cancer group compared with the noncancer group (57.9% [3165 of 5462 patients] vs 66.7% [13 046 of 19 555 patients]; P < .001). Single-organ support did not differ between the two groups but the provision of multi-organ support was less for the cancer group (25.4% [1386 of 5462 patients] vs 33.8% [6608 of 19 555 patients]; P < .001). Intensive care unit and hospital mortality were lower for the cancer population with 12.2% (666 of 5462 patients) vs 16.8% (3295 of 19 555 patients) (P < .001) of patients dying in ICU, and 22.9% (1252 of 5462 patients) vs 28.1% (5490 of 19 555 patients) (P < .001) dying in hospital.

608 of 19 555 patients]; P < .001). Intensive care unit and hospital mortality were lower for the cancer population with 12.2% (666 of 5462 patients) vs 16.8% (3295 of 19 555 patients) (P < .001) of patients dying in ICU, and 22.9% (1252 of 5462 patients) vs 28.1% (5490 of 19 555 patients) (P < .001) dying in hospital. ICU Patients Receiving Organ Support There were 16 211 surgical patients admitted to the ICU who received organ support during the study period (Table 1). Of these, 3165 (19.5%) had a solid tumor diagnosis. The APACHE II score was available for 92.0% of ICU patients without cancer (12 006 of 13 046) and 90.7% of ICU patients with cancer (2872 of 3165), and the median (IQR) value was 18 (14-24) and 18 (14-23). Within this group of patients, respiratory support was the most common mode of support for both the cancer and noncancer groups at 92.2% (2919 of 3165 patients) and 94.3% (12 300 of 13 046 patients), respectively. Cardiovascular support was provided to 50.0% of the cancer group (1584 of 3165 patients) and 54.6% of the noncancer group (7103 of 13 046 patients). Data pertaining to provision of renal replacement therapy was missing in 1365 patients without cancer (10.5%) and 301 patients with cancer (9.5%). Renal replacement therapy was not commonly provided in either group, but those patients in the cancer group had a lower prevalence of RRT (237 of 3165 patients [8.3%]) when compared with the noncancer group (1557 of 13 046 patients [13.3%]; P < .001). Single-organ support was more common in the cancer group (1779 of 3165 patients [56.2%]) with the noncancer group (6438 of 13 046 patients [49.3%]). Mortality was lower in the cancer group, with ICU mortality 18.6% (588 of 3165 patients) vs 23.5% (3066 of 13 046 patients), P < .001 and hospital mortality 31.4% (993 of 3165 patients) vs 36.0% (4693 of 13 065 patients), P < .001.

79 of 3165 patients [56.2%]) with the noncancer group (6438 of 13 046 patients [49.3%]). Mortality was lower in the cancer group, with ICU mortality 18.6% (588 of 3165 patients) vs 23.5% (3066 of 13 046 patients), P < .001 and hospital mortality 31.4% (993 of 3165 patients) vs 36.0% (4693 of 13 065 patients), P < .001. Outcomes of Underlying Tumor Type Table 2 lists all tumor types admitted to ICU during the study period along with ICU and hospital mortality. Short-term mortality varied considerably between different cancer types.

79 of 3165 patients [56.2%]) with the noncancer group (6438 of 13 046 patients [49.3%]). Mortality was lower in the cancer group, with ICU mortality 18.6% (588 of 3165 patients) vs 23.5% (3066 of 13 046 patients), P < .001 and hospital mortality 31.4% (993 of 3165 patients) vs 36.0% (4693 of 13 065 patients), P < .001. Outcomes of Underlying Tumor Type Table 2 lists all tumor types admitted to ICU during the study period along with ICU and hospital mortality. Short-term mortality varied considerably between different cancer types. Table 2. Frequency of Tumor Types in the Surgical ICU Population and Short-term Mortality Cancer Type Surgical ICU Cohort, No. (%) Mortality, % (95% CI) ICU Hospital Colorectal 2414 (44.2) 11.6 (10.3-12.9) 21.9 (20.2-23.6) Head and neck 610 (11.2) 5.6 (3.9-7.7) 11.0 (8.6-13.7) Stomach 419 (7.7) 10.7 (7.9-14.1) 22.0 (18.1-26.2) Esophagus 355 (6.5) 8.5 (5.8-11.8) 17.7 (13.9-22.1) Kidney 230 (4.2) 9.6 (6.1-14.1) 15.2 (10.8-20.5) Lung 220 (4.0) 35.9 (29.6-42.6) 51.4 (44.6-58.1) Bladder 172 (3.1) 7.0 (3.7-11.9) 26.7 (20.3-34.0) Ovary 130 (2.4) 14.6 (9.0-21.9) 29.2 (21.6-37.8) Prostate 102 (1.9) 8.8 (4.1-16.1) 21.6 (14.0-30.8) Uterus 102 (1.9) 10.8 (5.5-18.5) 16.7 (10.0-25.3) Breast 99 (1.8) 15.2 (8.7-23.8) 22.2 (14.5-31.7) Pancreas 72 (1.3) 25.0 (15.5-36.6) 47.2 (35.3-59.3) Liver 56 (1.0) 32.1 (20.3-46.0) 58.9 (45.0-71.9) Small intestine 50 (0.9) 14.0 (5.8-26.7) 32.0 (19.5-26.7) Thyroid 24 (0.4) 4.2 (1.1-21.1) 8.3 (1.0-27.0) Testis 16 (0.3) 18.8 (4.0-45.6) 18.8 (4.0-45.6) Mesothelioma 13 (0.2) 23.1 (5.0-53.8) 46.2 (19.2-74.9) Melanoma 11 (0.2) 0 (0-28.5)a 18.2 (2.3-51.8) Other 95 (1.7) 12.6 (6.7-21.0) 25.3 (16.9-35.2) Unknown 82 (1.5) 39.0 (28.4-50.4) 68.3 (57.1-78.1) Multiple 190 (3.5) 8.9 (5.3-13.9) 17.4 (12.3-23.5) Total 5462 (100) 12.2 (11.3-13.1) 22.9 (21.8-24.1) Abbreviation: ICU, intensive care unit.

23.1 (5.0-53.8) 46.2 (19.2-74.9) Melanoma 11 (0.2) 0 (0-28.5)a 18.2 (2.3-51.8) Other 95 (1.7) 12.6 (6.7-21.0) 25.3 (16.9-35.2) Unknown 82 (1.5) 39.0 (28.4-50.4) 68.3 (57.1-78.1) Multiple 190 (3.5) 8.9 (5.3-13.9) 17.4 (12.3-23.5) Total 5462 (100) 12.2 (11.3-13.1) 22.9 (21.8-24.1) Abbreviation: ICU, intensive care unit. a One-sided 97.5% CI.

23.1 (5.0-53.8) 46.2 (19.2-74.9) Melanoma 11 (0.2) 0 (0-28.5)a 18.2 (2.3-51.8) Other 95 (1.7) 12.6 (6.7-21.0) 25.3 (16.9-35.2) Unknown 82 (1.5) 39.0 (28.4-50.4) 68.3 (57.1-78.1) Multiple 190 (3.5) 8.9 (5.3-13.9) 17.4 (12.3-23.5) Total 5462 (100) 12.2 (11.3-13.1) 22.9 (21.8-24.1) Abbreviation: ICU, intensive care unit. a One-sided 97.5% CI. Colorectal cancer was the commonest tumor type admitted to ICU as a surgical admission with 2414 patients (44.2%). Other common tumors included head and neck (610 patients [11.2%]) and upper gastrointestinal tract (419 patients [7.7%] with stomach cancer and 355 patients [6.5%] with esophageal cancer). Colorectal cancer had a high rate of emergency hospitalization at 45.9% (1089 of 2372 patients) with a correspondingly high median (IQR) APACHE II score of 18 (14-22) compared with that seen in head and neck tumors (median [IQR], 15 [12-19]) or esophageal cancer (median [IQR], 14 [11-19]). Organ support showed some variation by underlying tumor type. Single-organ support was common in surgical patients with head and neck cancer (467 of 610 patients [76.6%]) compared with that seen in other common tumor types (553 of 2414 patients [22.9%]) with colorectal cancer and 141 of 355 patients (39.7%) with esophageal cancer. This difference was largely accounted for by the high rate of mechanical ventilation, with 558 of 598 patients with head and neck cancer (93.3%) receiving ventilation. There was a high proportion of patients receiving no organ support in the groups with colorectal cancer (1181 of 2414 patients, 48.9%) and stomach cancer (189 of 419 patients, 45.1%). These groups also had a larger proportion of patients with missing APACHE II scores (37.6% [908 of 2414 patients] and 29.8% [125 of 419 patients], respectively).

on of patients receiving no organ support in the groups with colorectal cancer (1181 of 2414 patients, 48.9%) and stomach cancer (189 of 419 patients, 45.1%). These groups also had a larger proportion of patients with missing APACHE II scores (37.6% [908 of 2414 patients] and 29.8% [125 of 419 patients], respectively). Factors Associated With Hospital Mortality Hospital mortality is described for different admission features in patients with and without cancer in Table 3. Hospital mortality was lower in the cancer group when categorized by the patient’s age, severity of illness, and admission year. Mortality was higher in the cancer group for patients admitted to the hospital electively (14.8%, 95% CI, 13.6%-16.1%; vs 12.8%, 95% CI, 11.7%-13.9%; P = .01) and for patients admitted to the hospital as an emergency (32.7%, 95% CI, 30.7%-34.7%; vs 29.1%, 95% CI, 28.4%-29.9%; P = .001). Odds ratios are reported in Table 4 for factors associated with hospital mortality. The factor with the greatest association with hospital mortality was severity of illness (APACHE II score, ≥20; OR, 4.67; 95% CI, 4.34-5.01) followed by age 65 years or older (OR, 2.14; 95% CI, 2.01-2.29) and emergency hospitalization (OR, 2.86; 95% CI, 2.62-3.12). Admission to the ICU directly from the surgical theater was protective (OR, 0.53; 95% CI, 0.49-0.56). Patients with cancer had an OR of 1.09 (95% CI, 1.00-1.19) for hospital mortality after adjustment for age, hospitalization type, admission source, sepsis, APACHE II score, and year of ICU admission.

5% CI, 2.62-3.12). Admission to the ICU directly from the surgical theater was protective (OR, 0.53; 95% CI, 0.49-0.56). Patients with cancer had an OR of 1.09 (95% CI, 1.00-1.19) for hospital mortality after adjustment for age, hospitalization type, admission source, sepsis, APACHE II score, and year of ICU admission. Table 3. Hospital Mortality in Patients With and Without Cancer by Admission Features Variable Patients, % (95% CI) P Value Noncancer (n = 19 555) Cancer (n = 5462) Age, y <65 20.0 (19.1-20.6) 15.1 (13.6-16.8) <.001 ≥65 37.8 (36.8-38.9) 27.6 (26.1-29.1) <.001 Hospitalization Elective 12.8 (11.7-13.9) 14.8 (13.6-16.1) .01 Emergency 29.1 (28.4-29.9) 32.7 (30.7-34.7) .001 Admission from Surgical theater 22.3 (21.5-23.0) 17.7 (16.6-18.9) <.001 Other 37.4 (36.3-38.5) 43.9 (40.9-46.9) <.001 Reason for admission Malignancy 11.9 (8.1-16.6) 12.4 (11.1-13.8) .81 Sepsis 40.6 (38.9-42.4) 49.0 (45.0-53.1) <.001 Other 25.9 (25.2-26.6) 26.1 (24.4-27.9) .85 APACHE II <20 15.4 (14.7-16.1) 14.1 (12.7-15.5) .10 ≥20 54.2 (52.9-55.5) 28.5 (45.8-51.3) <.001 Unknown 23.2 (21.9-24.5) 15.6 (13.9-17.4) <.001 ICU admission year 2000-2003 31.9 (30.8-33.0) 23.3 (21.6-25.1) <.001 2004-2007 27.6 (26.5-28.6) 23.5 (21.8-25.3) <.001 2008-2011 24.4 (23.4-25.5) 20.5 (18.0-23.2) .009 Abbreviations: APACHE, Acute Physiology and Chronic Health Evaluation (higher scores indicate increased severity of illness and corresponding mortality); ICU, intensive care unit.

3 31.9 (30.8-33.0) 23.3 (21.6-25.1) <.001 2004-2007 27.6 (26.5-28.6) 23.5 (21.8-25.3) <.001 2008-2011 24.4 (23.4-25.5) 20.5 (18.0-23.2) .009 Abbreviations: APACHE, Acute Physiology and Chronic Health Evaluation (higher scores indicate increased severity of illness and corresponding mortality); ICU, intensive care unit. Table 4. Multivariate Logistic Regression for Hospital Mortality Variable Univariate OR (95% CI) P Value Multivariate OR (95% CI) P Value Cancer 0.76 (0.71-0.82) <.001 1.09 (1.00-1.19) .048 Age, y <65 1 [Reference] 1 [Reference] ≥65 2.28 (2.15-2.42) <.001 2.14 (2.01-2.29) <.001 Hospitalization Elective 1 [Reference] 1 [Reference] Emergency 2.66 (2.47-2.86) <.001 2.86 (2.62-3.12) <.001 Admit from Surgical theater 0.43 (0.41-0.46) <.001 0.53 (0.49-0.56) <.001 Other 1 [Reference] 1 [Reference] Reason for admission Malignancya 0.40 (0.36-0.46) <.001 NA Sepsis 2.06 (1.91-2.22) <.001 1.42 (1.30-1.55) <.001 Other 1 [Reference] 1 [Reference] APACHE II score <20 1 [Reference] 1 [Reference] ≥20 6.35 (5.94-6.80) <.001 4.67 (4.34-5.01) <.001 Unknown 1.49 (1.38-1.61) <.001 1.46 (1.34-1.59) <.001 ICU admission year 2000-2003 1.35 (1.25-1.45) <.001 1.46 (1.34-1.58) <.001 2004-2007 1.15 (1.07-1.24) <.001 1.20 (1.10-1.31) <.001 2008-2011 1 [Reference] 1 [Reference] Abbreviations: APACHE, Acute Physiology and Chronic Health Evaluation (higher scores indicate increased severity of illness and corresponding mortality); ICU, intensive care unit; NA, not applicable; OR, odds ratio. a Not included in multivariate model owing to colinearity with cancer.

Table 4. Multivariate Logistic Regression for Hospital Mortality Variable Univariate OR (95% CI) P Value Multivariate OR (95% CI) P Value Cancer 0.76 (0.71-0.82) <.001 1.09 (1.00-1.19) .048 Age, y <65 1 [Reference] 1 [Reference] ≥65 2.28 (2.15-2.42) <.001 2.14 (2.01-2.29) <.001 Hospitalization Elective 1 [Reference] 1 [Reference] Emergency 2.66 (2.47-2.86) <.001 2.86 (2.62-3.12) <.001 Admit from Surgical theater 0.43 (0.41-0.46) <.001 0.53 (0.49-0.56) <.001 Other 1 [Reference] 1 [Reference] Reason for admission Malignancya 0.40 (0.36-0.46) <.001 NA Sepsis 2.06 (1.91-2.22) <.001 1.42 (1.30-1.55) <.001 Other 1 [Reference] 1 [Reference] APACHE II score <20 1 [Reference] 1 [Reference] ≥20 6.35 (5.94-6.80) <.001 4.67 (4.34-5.01) <.001 Unknown 1.49 (1.38-1.61) <.001 1.46 (1.34-1.59) <.001 ICU admission year 2000-2003 1.35 (1.25-1.45) <.001 1.46 (1.34-1.58) <.001 2004-2007 1.15 (1.07-1.24) <.001 1.20 (1.10-1.31) <.001 2008-2011 1 [Reference] 1 [Reference] Abbreviations: APACHE, Acute Physiology and Chronic Health Evaluation (higher scores indicate increased severity of illness and corresponding mortality); ICU, intensive care unit; NA, not applicable; OR, odds ratio. a Not included in multivariate model owing to colinearity with cancer. Longer-term Mortality Following ICU Admission Longer-term survival of surgical ICU patients with and without cancer is demonstrated in the Figure. While the initial mortality associated with the critical illness appears similar, the patients in the cancer group had a higher mortality by 6 months (31.3% vs 28.2%; P < .001). The survival curves continue to diverge and, by 4 years, the mortality of surgical ICU patients with cancer was 60.9% compared with 39.7% seen in the group without cancer.

ssociated with the critical illness appears similar, the patients in the cancer group had a higher mortality by 6 months (31.3% vs 28.2%; P < .001). The survival curves continue to diverge and, by 4 years, the mortality of surgical ICU patients with cancer was 60.9% compared with 39.7% seen in the group without cancer. Figure. Survival Analysis of Patients With and Without Cancer Following Surgical Intensive Care Unit Admission There was a statistically significant difference in survival by log-rank test (P < .001). Discussion In an unselected, population-based cohort, 1 in 5 surgical patients admitted to the ICU had a cancer diagnosis within 2 years of admission. These patients with cancer appeared to have an initial survival advantage over the noncancer cohort with favorable ICU and hospital mortality rates. Compared with patients without cancer, those with cancer were older and more likely to be admitted to the ICU following elective hospitalization; however, they had similar severity of illness. This finding is in keeping with those of previous studies.8,10

oncancer cohort with favorable ICU and hospital mortality rates. Compared with patients without cancer, those with cancer were older and more likely to be admitted to the ICU following elective hospitalization; however, they had similar severity of illness. This finding is in keeping with those of previous studies.8,10 Malignancy was the commonest reason for ICU admission in the cancer group. In the noncancer cohort, 1.2% had malignancy recorded for their admission diagnosis. It is possible that this was a diagnostic error in which malignancy was suspected prior to histologic confirmation. Alternatively, patients with cancer who were not residents of Scotland may have been treated in one of the included ICUs without appearing on the Scottish Cancer Registry. Severity of illness scores for patients with and without cancer were suggestive of a similar burden of acute illness. However, multiorgan support occurred more frequently in the group of patients without cancer. This difference could be due to treatment limitations imposed on cancer patients or a lower frequency of multiorgan failure. The cancer group had a higher proportion of patients without recorded APACHE II scores, which might reflect a “well” cohort of patients admitted only for postoperative observation and therefore excluded from scoring. When the group of patients without organ support was excluded, analysis of patients admitted to the ICU for organ support revealed a similar pattern of APACHE II scores between those with and without cancer, but lower mortality in the cancer group.

only for postoperative observation and therefore excluded from scoring. When the group of patients without organ support was excluded, analysis of patients admitted to the ICU for organ support revealed a similar pattern of APACHE II scores between those with and without cancer, but lower mortality in the cancer group. In both groups, patients admitted to the hospital electively had a favorable mortality compared with those admitted to the ICU after an emergency hospitalization. This finding might be attributable to the opportunity for preoperative optimization and selection of patients without significant comorbidity for intervention. When analyzed by emergency or elective hospitalization type, mortality was higher for patients with cancer compared with the noncancer group. However, mortality for the elective admission cancer group was lower than that in the emergency admission noncancer group. We propose that the large proportion of elective hospitalizations within the cancer group has a significant association with the apparent survival advantage of patients with cancer admitted to the ICU.

ver, mortality for the elective admission cancer group was lower than that in the emergency admission noncancer group. We propose that the large proportion of elective hospitalizations within the cancer group has a significant association with the apparent survival advantage of patients with cancer admitted to the ICU. After multivariate regression analysis, patients with cancer had only a marginally increased risk (OR, 1.09) of hospital mortality compared with the noncancer population. Factors that had a greater association with mortality were severity of illness, emergency hospitalization, and older age, which all increased the risk of hospital mortality, and admission directly from the surgical theater, which reduced the risk. This finding is consistent with previous studies that suggest that the immediate critical illness has a greater influence on short-term outcomes than the underlying cancer.6

tion, and older age, which all increased the risk of hospital mortality, and admission directly from the surgical theater, which reduced the risk. This finding is consistent with previous studies that suggest that the immediate critical illness has a greater influence on short-term outcomes than the underlying cancer.6 Intensive care unit and hospital mortality varied considerably by underlying cancer type consistent with that described by Bos and colleagues.11 Favorable outcomes were seen for patients with thyroid, head and neck, and kidney tumors. In contrast, high ICU and hospital mortality rates were observed in patients with pancreas, lung, and liver cancer for which survival outside the ICU setting is generally poorer compared with other tumor types. Patients with an unknown tumor type had the highest mortality rates demonstrated, although this might reflect a group of patients who died prior to definitive diagnosis or those for whom further investigation would be inappropriate owing to disease burden or severe comorbidities. While clinicians should be aware that not all cancers are equal in terms of survival following surgical ICU admission, mortality rates are such that none of the tumor types should automatically preclude admission.

ose for whom further investigation would be inappropriate owing to disease burden or severe comorbidities. While clinicians should be aware that not all cancers are equal in terms of survival following surgical ICU admission, mortality rates are such that none of the tumor types should automatically preclude admission. As more patients with cancer require critical care, clinical judgment needs to be informed by knowledge of outcomes in similar patients. The hospital mortality described for patients with cancer who are admitted to the ICU after elective hospitalization in this study is significantly higher than that described by Bos et al9 (14.8% vs 4.7%, respectively). However, the study by Bos et al only included patients who had a planned admission to the ICU. In comparison, patients in the present study may have had a planned admission to the hospital but required admission to the ICU only after an unexpected complication. In the same setting, surgical patients with an unplanned admission to the ICU had a hospital mortality of 17.4%,10 which is nearly half of that described in this study. This low mortality may be explained by the lower use of organ support in the study by Bos et al and the inclusion of patients undergoing elective surgery but admitted as an emergency after a complication. These differences highlight the importance of reporting a comparator group within the same study population to allow any real differences to be appreciated.

e lower use of organ support in the study by Bos et al and the inclusion of patients undergoing elective surgery but admitted as an emergency after a complication. These differences highlight the importance of reporting a comparator group within the same study population to allow any real differences to be appreciated. While immediate outcomes in this study may favor the group with cancer, this advantage was reversed by 6 months and survival thereafter was poorer in the group of patients with an underlying tumor. By 4 years, the difference in survival was 39.1% compared with 60.3% for surgical ICU patients with and without cancer. To our knowledge, no previous study has described longer-term survival for ICU patients with cancer compared with those without cancer to this degree. It has been established in the literature that short-term outcomes are related to the critical illness rather than the underlying tumor,6 and it seems likely that as patients recover from their critical illness, comorbidities such as cancer have an increasing association with survival in the longer term.

o this degree. It has been established in the literature that short-term outcomes are related to the critical illness rather than the underlying tumor,6 and it seems likely that as patients recover from their critical illness, comorbidities such as cancer have an increasing association with survival in the longer term. Strengths and Limitations A strength of this study is that it presents the characteristics of patients with cancer admitted to nonspecialized ICUs from a surgical population. The type of cancer was verified from cancer registration data. Our findings therefore are representative of practice in general hospitals and suitable for generalization. However, it is probable that APACHE II scores and organ support that were not recorded are not missing at random13 and might depend on the severity of illness, the admitting ICU, and whether the patient died during the ICU stay. Odds ratios demonstrated a slight increase in hospital mortality in patients without an APACHE II score recorded (OR, 1.46) and the reason for this is unknown. This group of patients with unrecorded APACHE II scores is likely to be a mix of those who were excluded from scoring because of a high-dependency unit admission (in which survival would be expected to be favorable) and those who died before full scoring was possible. Owing to the retrospective design of this study, we do not know the exact reason for this finding. A further limitation of this study is that our analysis was restricted to the information already collected and we were therefore unable to report on specifics, such as performance status or tumor stage, both of which are known to have a significant association with survival.

not know the exact reason for this finding. A further limitation of this study is that our analysis was restricted to the information already collected and we were therefore unable to report on specifics, such as performance status or tumor stage, both of which are known to have a significant association with survival. Conclusions We found that cancer is a common condition present in surgical patients admitted to the ICU. Patients with cancer were more likely to have been admitted to the hospital electively and receive no organ support in the ICU. Short-term outcomes in patients with cancer admitted to the ICU varied significantly by underlying tumor type, severity of illness, and admission features. Contrary to previous studies, ICU patients with cancer had favorable short-term outcomes compared with ICU patients without cancer, although this survival advantage had disappeared by 6 months. After adjusting for other prognostic variables, ICU patients with cancer did not have a meaningful increase in their risk of hospital mortality compared with patients without cancer. In view of these findings a diagnosis of cancer should not preclude admission to an ICU in surgical patients. To be able to better inform admission decisions, further work is needed on individual cancers to determine which features have prognostic value.

Introduction Over the course of the Iraq and Afghanistan conflicts, coalition military service members have been less likely to die of their injuries than service members from any other time in recorded history. This unprecedented battlefield survival was the result of a purposeful commitment to coordinate advances in trauma care with immediate frontline intervention and rapid transport to facilities with escalating surgical capabilities. The survival rate of individuals after battlefield injury has more than doubled when compared with the Vietnam War. An essential component of this improved trauma capability has been the rapid stabilization of the injured and their managed evacuation through a tiered system of care, each with escalating and increasingly specialized medical capabilities. The US military’s commitment to such a system took the form of the Joint Trauma System, which coupled rapid tiered response with data registries, ongoing performance improvement, and the development and implementation of clinical practice guidelines. Advances were both technical (eg, tourniquets, tranexamic acid, and hemostatic dressings) and systems-based (eg, advanced care during transport). An integrated continuum of care from the point of injury (POI) through rehabilitation included the following levels: Role 1–tactical combat casualty care, in which frontline personnel perform hemorrhage control, resuscitation, and airway protection measures proximate to the POI;

An essential component of this improved trauma capability has been the rapid stabilization of the injured and their managed evacuation through a tiered system of care, each with escalating and increasingly specialized medical capabilities. The US military’s commitment to such a system took the form of the Joint Trauma System, which coupled rapid tiered response with data registries, ongoing performance improvement, and the development and implementation of clinical practice guidelines. Advances were both technical (eg, tourniquets, tranexamic acid, and hemostatic dressings) and systems-based (eg, advanced care during transport). An integrated continuum of care from the point of injury (POI) through rehabilitation included the following levels: Role 1–tactical combat casualty care, in which frontline personnel perform hemorrhage control, resuscitation, and airway protection measures proximate to the POI; Role 2–time and distance gaps from the POI to definitive surgical care, which are bridged via forward surgical teams capable of providing damage control resuscitation and surgery before rapid evacuation; Role 3–combat support hospitals, which provide the highest level of care in the conflict zone. After stabilization, casualties are moved out of the country to definitive care facilities; and Role 4–well-resourced definitive care facilities, which are located away from the conflict zone.

Role 2–time and distance gaps from the POI to definitive surgical care, which are bridged via forward surgical teams capable of providing damage control resuscitation and surgery before rapid evacuation; Role 3–combat support hospitals, which provide the highest level of care in the conflict zone. After stabilization, casualties are moved out of the country to definitive care facilities; and Role 4–well-resourced definitive care facilities, which are located away from the conflict zone. The successes of military trauma systems demonstrate the potential of advanced trauma management, and many of these advances have been successfully adopted into civilian trauma settings. In contrast, the humanitarian response in conflict settings not only has to provide trauma care but also emergency surgical care to the affected population. Providing humanitarian care in insecure environments poses major pragmatic and ethical challenges. Protracted intrastate conflicts that use siege warfare, the use of explosive weapons in densely populated urban settings, and the targeting of health facilities and other essential infrastructure (eg, water systems, food supply chains) can cause high levels of civilian mortality. This context also poses obstacles to the establishment of advanced trauma systems by humanitarian actors. Of particular concern are the positioning of humanitarian medical personnel close to the front lines, the control of evacuation pathways for casualties, secure supply chains, adequate human resources, and most fundamentally, the safety of patients and humanitarian personnel.

anced trauma systems by humanitarian actors. Of particular concern are the positioning of humanitarian medical personnel close to the front lines, the control of evacuation pathways for casualties, secure supply chains, adequate human resources, and most fundamentally, the safety of patients and humanitarian personnel. Several events have underscored the need to revise humanitarian protocols. The 2010 earthquake in Haiti exposed the inadequate training and coordination of emergency medical personnel, which resulted in care that has been described as “medically shameful.” Partly in response to this event, in 2013, the World Health Organization published what is called the Blue Book, a set of guidelines that established a framework of overarching standards for teams operating in sudden-onset disasters. Similar guidelines for the humanitarian response to conflict do not currently exist. The health response to the Battle of Mosul, Iraq, in 2016-2017 raised serious concerns regarding the deployment of humanitarian medical personnel under the direct protection of Iraqi security forces. The Mosul experience and the subsequent fighting in Raqqa, Syria, also raised concerns regarding military-civilian coordination and the responsibilities of militaries for the evacuation and care of civilian casualties.

he deployment of humanitarian medical personnel under the direct protection of Iraqi security forces. The Mosul experience and the subsequent fighting in Raqqa, Syria, also raised concerns regarding military-civilian coordination and the responsibilities of militaries for the evacuation and care of civilian casualties. While responsibility for frontline care of the wounded should rest first with the parties to the conflict, humanitarian organizations increasingly have become the major providers of medical care in areas of violent conflict. Humanitarian response to conflict is dissimilar from disaster and current World Health Organization Blue Book guidelines do not give adequate guidance. Unarmed humanitarian medical groups must operate in insecure environments and personnel must also adhere to the principles of humanity, neutrality, impartiality, and independence—requirements that place special demands on humanitarian systems. Civilian population needs differ from those of military personnel. Moreover, the military focus on frontline stabilization and rapid evacuation of patients is particularly difficult to implement in humanitarian settings. Unless these challenges are addressed, these dynamics can lead to high rates of preventable death and disability.

ation needs differ from those of military personnel. Moreover, the military focus on frontline stabilization and rapid evacuation of patients is particularly difficult to implement in humanitarian settings. Unless these challenges are addressed, these dynamics can lead to high rates of preventable death and disability. In response to these concerns, the Stanford Humanitarian Surgical Response in Conflict Working Group was established on March 20, 2018, to reevaluate the humanitarian medical response to conflict. The Group’s deliberations culminated in an in-person convening from August 3 to August 5, 2018, which produced a consensus framework for humanitarian trauma systems in conflict settings. The framework’s goal was to translate the progress made by trauma systems to the pragmatic realities of humanitarian medical provision in areas of violent conflict.

nated in an in-person convening from August 3 to August 5, 2018, which produced a consensus framework for humanitarian trauma systems in conflict settings. The framework’s goal was to translate the progress made by trauma systems to the pragmatic realities of humanitarian medical provision in areas of violent conflict. Methods Thirty-five participants were invited to the Stanford Humanitarian Surgical Response in Conflict Working Group. Contributors were selected on the basis of sector expertise, organization leadership, publication record in trauma care, trauma systems development, and humanitarian surgical care. This multinational group included senior representatives from civilian and military trauma systems, international humanitarian nongovernmental organizations, such as Médecins Sans Frontières, Samaritan’s Purse, International Committee of the Red Cross, World Health Organization, and academic trauma system and research centers. The group’s charge was to design a consensus framework for a new model for surgical humanitarian response, translating advances in combat casualty care to the modern humanitarian context. The first iteration of this framework was designed for protracted urban conflict, such as that seen in Syria and Iraq, with the understanding that this schema could be adapted to different humanitarian contexts in the future.

ian response, translating advances in combat casualty care to the modern humanitarian context. The first iteration of this framework was designed for protracted urban conflict, such as that seen in Syria and Iraq, with the understanding that this schema could be adapted to different humanitarian contexts in the future. The working group’s process incorporated core elements of a modified Delphi process combined with formal consensus development methods with iterative rounds of inclusive, anonymized input leading to a transparent derivation of final decisions. Group members received a compilation of current protocols, resource lists, and relevant health services research on humanitarian and military trauma care in conflict settings. Documents were circulated electronically for feedback and voting. At each stage, input was synthesized and incorporated into revised documents that were recirculated for review. Members had the opportunity to comment, dissent, and revise their opinion after viewing the blinded results of others’ feedback. In addition, the group organizer prepared a final set of documents based on all feedback that served as the basis for discussion at the in-person convening.

that were recirculated for review. Members had the opportunity to comment, dissent, and revise their opinion after viewing the blinded results of others’ feedback. In addition, the group organizer prepared a final set of documents based on all feedback that served as the basis for discussion at the in-person convening. From August 3 to 5, 2018, a 3-day, in-person convening occurred at Stanford University, Stanford, California. The proceedings consisted of presentations on the perspectives and practices of the represented organizations, as well as small-group design activities and entire-group discussion for transparent consensus building. No round proceeded until the objections of all members had been solicited, addressed, and resolved through discussion and consensus voting, and formal consensus had been achieved. The Stanford University Institutional Review Board determined that this research does not involve human subjects and therefore waived the need for informed consent.

the objections of all members had been solicited, addressed, and resolved through discussion and consensus voting, and formal consensus had been achieved. The Stanford University Institutional Review Board determined that this research does not involve human subjects and therefore waived the need for informed consent. Humanitarian Response: Technical Framework The objective of this framework is to provide a standardized approach to minimize preventable death and disability of people with surgical needs during conflict. This population includes patients with conflict-related violent injury as well as other surgical needs, such as obstructed labor, soft-tissue infections, nonviolent trauma, and intra-abdominal emergencies. Similar to the Joint Trauma System, this proposed framework consists of an integrated tiered chain of care with continuity from POI to definitive treatment and rehabilitation as well as systemwide advances (eg, injury prevention, data collection, and quality improvement).

iolent trauma, and intra-abdominal emergencies. Similar to the Joint Trauma System, this proposed framework consists of an integrated tiered chain of care with continuity from POI to definitive treatment and rehabilitation as well as systemwide advances (eg, injury prevention, data collection, and quality improvement). Results Level 1: Community First Responders Expansion of tactical combat casualty care to all service members enabled the US military to decrease preventable prehospital deaths. In the humanitarian context, training civilian first responders should minimize responder risk and maximize opportunities to improve POI care. Basic skills should include (1) safe scene management (eg, removing responders and casualties from dangerous situations), (2) airway protection through jaw-thrust and chin-lift maneuvers and lateral trauma position for transportation, (3) bleeding control with manual compression and wound packing, (4) protecting the injured from the environment, and (5) rapid transportation of the injured to care. Bystander tourniquet application is not recommended, as transport may be prolonged and misapplied tourniquets may be ineffectual or harmful. Spine immobilization should also be avoided given prolonged transport times, reliance on makeshift transport, potential loss of airway, and difficulty managing complex spinal injury in this context. Interventions for cardiopulmonary arrest are not recommended, as individuals with no pulse do not survive in this environment.

immobilization should also be avoided given prolonged transport times, reliance on makeshift transport, potential loss of airway, and difficulty managing complex spinal injury in this context. Interventions for cardiopulmonary arrest are not recommended, as individuals with no pulse do not survive in this environment. More advanced training of a subset of community first responders could improve trauma outcomes in low-resource settings. Trauma first responders would complete identical training of the basic community responders and receive advanced training in (1) triage including identification of individuals who died or had injuries incompatible with life, (2) basic fracture immobilization, (3) preparation of casualties for transport, and (4) logistical options for transport adapted to the local context. In addition, trauma first responders ideally should provide ongoing community education and conflict first-aid training. Level 2: Trauma Stabilization Point The trauma stabilization point (TSP) is proposed as the first site of care staffed by trained medical (not surgical) personnel. The TSP’s primary function is to provide far-forward emergency resuscitation and stabilization and must be capable of functioning in resource-constrained environments. The objective at this site is to control hemorrhage, manage airway emergencies, and initiate timely transfer to a higher level of care. Surgical procedures are not performed at this site.

ovide far-forward emergency resuscitation and stabilization and must be capable of functioning in resource-constrained environments. The objective at this site is to control hemorrhage, manage airway emergencies, and initiate timely transfer to a higher level of care. Surgical procedures are not performed at this site. By moving medical capabilities as close to the POI as possible, the TSP represents a significant change from most humanitarian responses. The role and location of the TSP must be continuously reassessed in light of conflict dynamics and security considerations. The utility of TSPs may be limited in certain contexts, particularly where fighting is sporadic or front lines are poorly defined. The potential contribution of the TSP is contingent on the presence of a system of care meeting the following requirements: (1) adequate transport, (2) capability to maintain care en route, and (3) transfer to a receiving facility able to provide more-advanced care. The TSP would be the first site of medical triage influenced by patient injury and use of resources. The reciprocity between hemorrhage control and triage has been well recognized in the military trauma system of care. Life-saving measures for survivable injuries prioritizing circulation and control of massive hemorrhage with nonsurgical management of airway emergencies have been reported to decrease preventable deaths. Early hemorrhage control allows patients to survive; in addition, the triage category can be downstaged, as in the example of extremity hemorrhage.

ble injuries prioritizing circulation and control of massive hemorrhage with nonsurgical management of airway emergencies have been reported to decrease preventable deaths. Early hemorrhage control allows patients to survive; in addition, the triage category can be downstaged, as in the example of extremity hemorrhage. Based on military data, TSPs would ideally be located within 10 minutes of the POI. Given contextual constraints, the goal should be within 20 minutes. Therefore, rapid patient evacuation is an essential component of the TSP. The TSP services should include (1) hemorrhage control via tourniquets and/or placement of a pelvic binder; (2) resuscitation, including tranexamic acid administration, intravenous and intraosseous line placement, and crystalloid infusion; (3) initial management of chest injury causing airway or circulatory compromise via decompression of the pleural space, application of chest seals, and insertion of pleural drains; (4) initial management of life-threatening infection via resuscitation and antibiotic administration as well as wound irrigation and debris removal; and (5) pain control. Owing to poor long-term prognosis, resuscitation of pulseless patients and emergency resuscitative thoracotomy should not be performed. The advisability of initiating invasive procedures at this site is contingent on the ability to sustain care beyond the TSP. Only patients requiring a higher level of care should be transferred to the definitive facility. The TSP is not intended to serve as a site of primary care or management of nontraumatic medical or surgical needs. In addition, definitive management and discharge of patients with non–life-threatening injury should be provided at the TSP, including acute wound and closed fracture management, pain management, and tetanus prevention. By consensus, context-specific recommendations for TSP personnel, which is a controversial subject, fell outside the group’s mandate.

t and discharge of patients with non–life-threatening injury should be provided at the TSP, including acute wound and closed fracture management, pain management, and tetanus prevention. By consensus, context-specific recommendations for TSP personnel, which is a controversial subject, fell outside the group’s mandate. Early component or whole blood transfusion has been reported to improve survival in patients with hemorrhagic shock and is the equalizer for long transport times to a higher level of care. Transfusion capability, which may be possible through walking blood banks, would augment the TSP. However, although desirable, blood transfusion at the TSP is currently not available in most settings. Level 3 Framework Definitive Care Facility After stabilization at the TSP, patients in need of additional care should be transported to a definitive care facility. This site would be the first point at which surgical care will be provided and must be capable of treating injuries as well as emergency surgical and obstetrical conditions. These facilities require significant investment in material and human resources to provide quality care. Minimum essential procedures provided at this site are presented in Box 1. Box 1. Level 3 Definitive and Contingency Care Facility and Advanced Care Capabilities Definitive Care Facility Imaging: radiography and ultrasonography Fracture management (open and closed) Management of spinal cord or column injuries Definitive surgical burn care Operative treatment of abdominal and obstetrical surgical emergencies Open skull fracture management

Box 1. Level 3 Definitive and Contingency Care Facility and Advanced Care Capabilities Definitive Care Facility Imaging: radiography and ultrasonography Fracture management (open and closed) Management of spinal cord or column injuries Definitive surgical burn care Operative treatment of abdominal and obstetrical surgical emergencies Open skull fracture management Amputation and fasciotomy Herniorrhaphy (nonelective, primary tissue) Emergency genitourinary procedures Complex wound closure and skin graft Enucleation Operative management of fractured mandible Local or rotational flap Definitive vascular reconstruction Complex surgical treatment of wounds and infection Regional, spinal, and general anesthesia with intubation Transfusion services Complex perioperative care Intermediate level of care above ward Postanesthesia care unit Palliative care (eg, high-mortality burns) Contingency Facilitya Imaging: ultrasonography Diagnostic peritoneal lavage or aspiration Closed fracture management Conservative management of spinal cord or column injuries Emergency burn escharotomy and acute burn management Basic neck exploration Suprapubic tube placement Temporary vascular stabilization including shunt Open skull fracture management Amputation and fasciotomy Operative treatment of abdominal and obstetrical surgical emergencies Surgical treatment of wounds and infection Regional, spinal, and general anesthesia with intubation Postanesthesia recovery in operating suite Basic transfusion services Pain and symptom management Advanced Capability Packageb Medical Care Ventilators Intensive care unit nursing staff Central venous catheters Cardiac monitoring IV inotropes

Surgical treatment of wounds and infection Regional, spinal, and general anesthesia with intubation Postanesthesia recovery in operating suite Basic transfusion services Pain and symptom management Advanced Capability Packageb Medical Care Ventilators Intensive care unit nursing staff Central venous catheters Cardiac monitoring IV inotropes Surgical Services Cardiothoracic Neurosurgical Reconstructive a This facility would provide damage control surgery en route to definitive surgery as needed. b An advanced capability package can be used to increase the complexity and scope of surgery performed in the definitive care facilities by providing specialist surgeons and critical care services.

Surgical Services Cardiothoracic Neurosurgical Reconstructive a This facility would provide damage control surgery en route to definitive surgery as needed. b An advanced capability package can be used to increase the complexity and scope of surgery performed in the definitive care facilities by providing specialist surgeons and critical care services. Contingency Facility An innovation proposed by this group is the contingency facility. This facility should provide damage control surgery en route to definitive care as needed. Situations dictating the need for a contingency site include (1) the pace and volume of incoming casualties, (2) anticipated surge in casualties, (3) ability to provide timely damage-control surgery, and (4) other threats to the survival gains made at the TSP. Patients with critical status (ie, triage category red) should optimally receive surgical care within 45 minutes but no longer than 60 minutes after leaving the TSP. For those with less-critical conditions (ie, triage category yellow), this timeline extends to surgery within 4 hours optimally but no more than 6 hours. Although these timelines are ambitious in insecure environments, similar transport times have been achieved in other resource-constrained settings. Emergency abdominal and obstetric procedures could also be done at this site if timely transfer to the definitive site is not possible within a time frame that maximizes survival (Box 1). Contingency facilities must be mobile and, as at the TSP, stringent triage criteria must be used given finite resources and the inability to provide mechanical ventilation while awaiting transport.

t this site if timely transfer to the definitive site is not possible within a time frame that maximizes survival (Box 1). Contingency facilities must be mobile and, as at the TSP, stringent triage criteria must be used given finite resources and the inability to provide mechanical ventilation while awaiting transport. Advanced Capability Package Another proposed innovation is a standardized advanced capability package that can be used by definitive care facilities to provide higher-level specialty surgical and critical care. The advanced capability package would consist of personnel with specialized surgical training (eg, cardiothoracic, neurologic, plastic surgeons) and equipment (eg, mechanical ventilation, central venous catheters, advanced monitoring, specialized surgical equipment), which could be integrated into the core platform as circumstances permit. Level 4: Reconstruction and Rehabilitation Despite resource limitations, the system should seek to improve functional outcomes by including basic reconstructive and rehabilitative services (Table 1). However, the complexity of reconstructive care should not exceed contextual realities in terms of hygiene, required skill, nursing, physiotherapy, postoperative care capabilities, and outpatient or community rehabilitation services. The decision to perform advanced reconstructive procedures must weigh the risks of potential complications. Early reconstruction should prioritize procedures that optimize functional outcomes, emphasizing physiotherapy and rehabilitation as integral components of the process.

tient or community rehabilitation services. The decision to perform advanced reconstructive procedures must weigh the risks of potential complications. Early reconstruction should prioritize procedures that optimize functional outcomes, emphasizing physiotherapy and rehabilitation as integral components of the process. Table 1. Reconstructive and Rehabilitative Services Level Procedure Minimum Burn reconstruction, including skin grafts and contracture release Local flaps for soft-tissue coverage Stump revision and provision of postamputation care Reanastomosis of bowel stoma Treatment of acute osteomyelitis Physiotherapy, including provision of crutches, walking frames Conservative management of spinal cord/column injuries Mental health services Context dependent Internal fixation of fractures Not to be performed (nonexhaustive) Cosmetic surgery Dental reconstruction Complex congenital disorders Free flaps Arthroplasty Repair of obstetrical fistula Limb lengthening/bone transport

Physiotherapy, including provision of crutches, walking frames Conservative management of spinal cord/column injuries Mental health services Context dependent Internal fixation of fractures Not to be performed (nonexhaustive) Cosmetic surgery Dental reconstruction Complex congenital disorders Free flaps Arthroplasty Repair of obstetrical fistula Limb lengthening/bone transport A significant percentage of patients who experience blast and explosion injuries require amputation. It is critical for surgeons to consider function in the creation of the residual limb. Of equal importance is training in adaptive devices, safe transfer techniques, and physiotherapy for residual limb preparation. When feasible, the provision of adequate prostheses would permit patients to regain additional function. At present there are few organizations with the means to provide and maintain prosthetics in these settings. Efforts should be made to establish international networks and allocate funds for prosthesis provision and follow-up. Burn injuries are common in both conflict and low-income contexts. Therefore, acute burn care, reconstruction, and rehabilitation are critical functions to prevent death and disability. Mental health services should be an integral part of care and follow-up planning at acute care facilities. In addition, reconstruction of congenital disorders and other complex non–conflict-related conditions should be deferred during active conflict given resource constraints.

unctions to prevent death and disability. Mental health services should be an integral part of care and follow-up planning at acute care facilities. In addition, reconstruction of congenital disorders and other complex non–conflict-related conditions should be deferred during active conflict given resource constraints. Systemwide Requirements In addition to the technical requirements and competencies necessary at each level of care, there are features that should be integrated within the system to optimize care. These features include predeployment education, injury prevention, data collection, and quality improvement.

unctions to prevent death and disability. Mental health services should be an integral part of care and follow-up planning at acute care facilities. In addition, reconstruction of congenital disorders and other complex non–conflict-related conditions should be deferred during active conflict given resource constraints. Systemwide Requirements In addition to the technical requirements and competencies necessary at each level of care, there are features that should be integrated within the system to optimize care. These features include predeployment education, injury prevention, data collection, and quality improvement. Humanitarian Principles and Context The ability for humanitarian organizations to provide surgical care proximate to the time of injury is complicated by security and access constraints. Humanitarian medical teams are unarmed and may come under fire if operating near the front line or, increasingly, are directly targeted. Attempts to reconcile the dual imperatives of safety and rapid medical intervention have proven controversial. Placing humanitarian medical personnel under the protection of combatant forces challenges the long-standing humanitarian principles of neutrality and independence, which are in part designed to enhance humanitarian access and safety. Although these tensions are unresolved, it remains important to distinguish humanitarian activities from other forms of assistance associated with “interest-conflicted” parties, which may include the host state. Efforts to document attacks on medical personnel and/or zones established to care for the wounded and sick and hold perpetrators accountable should be strongly supported.

o distinguish humanitarian activities from other forms of assistance associated with “interest-conflicted” parties, which may include the host state. Efforts to document attacks on medical personnel and/or zones established to care for the wounded and sick and hold perpetrators accountable should be strongly supported. Given the importance and complexity of these issues, all medical personnel serving in conflict areas should have basic training in humanitarian ethics and/or medical ethics specific to the setting or armed conflict, international humanitarian law, and knowledge of the local sociocultural and political context. Special attention should be paid to the principle of impartiality, which requires that assistance be provided based on medical need regardless of a patient’s political affiliation or preinjury combatant status. Counter-terrorism strategies can conflict with medical impartiality, and potential conflicts should be managed with an understanding of international humanitarian law and informed anticipation of these pressures. Standardized, pragmatic educational materials for medical personnel and predeployment checklists may prove useful (Box 2). Box 2. Predeployment Minimal Training Standards: Humanitarian Principles and Context Training in medical ethics, humanitarian principles, and international humanitarian law Training in international and domestic laws governing medical action and patient protections Context briefing on the local setting, including cultural and political dynamics

Box 2. Predeployment Minimal Training Standards: Humanitarian Principles and Context Training in medical ethics, humanitarian principles, and international humanitarian law Training in international and domestic laws governing medical action and patient protections Context briefing on the local setting, including cultural and political dynamics Security protocols and orientation to operations in high-risk environments, kidnapping, handling of unexploded ordnance and nuclear, biological, and chemical defense procedures Code of professional conduct/behavioral commitments Policies for media relations, including the ethical use of social media

Context briefing on the local setting, including cultural and political dynamics Security protocols and orientation to operations in high-risk environments, kidnapping, handling of unexploded ordnance and nuclear, biological, and chemical defense procedures Code of professional conduct/behavioral commitments Policies for media relations, including the ethical use of social media Injury Prevention Injury prevention may provide additional opportunities to reduce preventable death and disability (Table 2). Prevention measures should include efforts to anticipate and mitigate risks associated with conflict, including timely escape, avoidance of landmines and unexploded ordnance, and safety around damaged infrastructures. First responders, whether lay or professional, should have training in safe recovery of the wounded, use of personal protection, risk reduction strategies, and contingency planning. Prevention programs should engage patients, individuals, community leaders, civil societies, nongovernmental organizations, and when appropriate, military stakeholders and/or governments. Use of local systems to disseminate information (eg, public service announcements via radio or social media, training of community health workers) may improve their reach. Population safeguards, such as early warning systems and egress assistance, may also prove to be useful. Table 2. Functions and Representative Activities for Injury Prevention in Conflict Settings Function Representative Activities Strengthen individual knowledge and skills Landmine/unexploded ordnance risk reduction campaign

Injury Prevention Injury prevention may provide additional opportunities to reduce preventable death and disability (Table 2). Prevention measures should include efforts to anticipate and mitigate risks associated with conflict, including timely escape, avoidance of landmines and unexploded ordnance, and safety around damaged infrastructures. First responders, whether lay or professional, should have training in safe recovery of the wounded, use of personal protection, risk reduction strategies, and contingency planning. Prevention programs should engage patients, individuals, community leaders, civil societies, nongovernmental organizations, and when appropriate, military stakeholders and/or governments. Use of local systems to disseminate information (eg, public service announcements via radio or social media, training of community health workers) may improve their reach. Population safeguards, such as early warning systems and egress assistance, may also prove to be useful. Table 2. Functions and Representative Activities for Injury Prevention in Conflict Settings Function Representative Activities Strengthen individual knowledge and skills Landmine/unexploded ordnance risk reduction campaign Burn and electrical injury prevention Instruction on safe management of structural hazards Develop community awareness and engagement Public service announcements Engagement with community health workers Train-the-trainer models for safety promotion Educate providers Injury risk screening and reduction in health facilities Awareness of gender-based violence signs and resources

Instruction on safe management of structural hazards Develop community awareness and engagement Public service announcements Engagement with community health workers Train-the-trainer models for safety promotion Educate providers Injury risk screening and reduction in health facilities Awareness of gender-based violence signs and resources Safe recovery education for first responders Foster coalitions Interagency collaboration for prevention initiatives Coordination with existing injury prevention actors and campaigns Population safeguards Early warning systems and egress assistance Advocate for safety Mobilizing social support for specific prevention efforts Bringing forward/supporting relevant treaties Data Collection and Quality Improvement Advances in trauma systems development have been predicated on the ability to evaluate data from trauma registries such as the Department of Defense Trauma Registry and American College of Surgeons National Trauma Data Bank. A clinical data collection system is foundational for understanding the evolving epidemiology of surgical disease in conflict and for improving the quality of response.

y to evaluate data from trauma registries such as the Department of Defense Trauma Registry and American College of Surgeons National Trauma Data Bank. A clinical data collection system is foundational for understanding the evolving epidemiology of surgical disease in conflict and for improving the quality of response. The recommended minimum data that should be collected at each point of care and coordinated among all actors are outlined in Box 3. Desired data elements include the geographic place of injury, clinical complications, functional status at disposition and, if possible, measures of long-term patient outcomes. If multiple organizations are involved, responsibilities for data collection and analysis should be clearly defined and occur at consistent points throughout the system. The registration and transmission of data must use security safeguards to protect the identity of the patient, maintain patient safety, and link individual records across the continuum of care. To minimize the task burden and maximize utility, data collection should be completed electronically and include a limited number of elements at each site. In addition, systematic data analysis should be undertaken in real time to ensure immediate feedback and response refinement in a rapidly changing environment. Box 3. Minimum Data Set for Humanitarian Trauma System Required Patient demographic information (sex, age) Mechanism and anatomic location of injury Estimated time of injury Time of arrival at each point of care Mode of transport to point of care Vital signs Triage category and Kampala Trauma Score

The recommended minimum data that should be collected at each point of care and coordinated among all actors are outlined in Box 3. Desired data elements include the geographic place of injury, clinical complications, functional status at disposition and, if possible, measures of long-term patient outcomes. If multiple organizations are involved, responsibilities for data collection and analysis should be clearly defined and occur at consistent points throughout the system. The registration and transmission of data must use security safeguards to protect the identity of the patient, maintain patient safety, and link individual records across the continuum of care. To minimize the task burden and maximize utility, data collection should be completed electronically and include a limited number of elements at each site. In addition, systematic data analysis should be undertaken in real time to ensure immediate feedback and response refinement in a rapidly changing environment. Box 3. Minimum Data Set for Humanitarian Trauma System Required Patient demographic information (sex, age) Mechanism and anatomic location of injury Estimated time of injury Time of arrival at each point of care Mode of transport to point of care Vital signs Triage category and Kampala Trauma Score Procedures performed Disposition outcome (dead/alive) Time of disposition Intended destination at disposition Desirable Geographic place of injury (if not risking patient safety) Clinical complications Information about the patient’s basic functional status at disposition Any available data about long-term patient outcomes

Triage category and Kampala Trauma Score Procedures performed Disposition outcome (dead/alive) Time of disposition Intended destination at disposition Desirable Geographic place of injury (if not risking patient safety) Clinical complications Information about the patient’s basic functional status at disposition Any available data about long-term patient outcomes Discussion This framework presents minimum standards for humanitarian surgical response in areas beset by armed conflict. Even in high-risk security and resource-constrained conflict settings there exists a realistic potential to prevent death and disability. Adapting advances in trauma systems to the humanitarian context could also improve outcomes in the care of other surgical emergencies. The implementation of trauma systems has consistently reported reduction of preventable death and disability in both military as well as civilian environments. This framework builds on this evidence, optimizing rapid intervention to manage the leading causes of death, hemorrhage, and airway compromise. Military and civilian communities have approached these challenges by developing coordinated systems of trauma care that match the nature and urgency of patient needs with provision of escalating surgical capabilities. Communication between system components is also essential to facilitate clinical standards, transitions of care, data collection, and quality improvement.

se challenges by developing coordinated systems of trauma care that match the nature and urgency of patient needs with provision of escalating surgical capabilities. Communication between system components is also essential to facilitate clinical standards, transitions of care, data collection, and quality improvement. Limitations There are significant challenges to the implementation of this framework; however, its utility is based on providing a basic blueprint that can be adapted for different conflict settings. The Stanford Working Group also identified areas for further consideration, including (1) standardized technical and contextual training for personnel deployed to conflict settings, (2) development of a uniform data registry with embedded quality improvement capabilities, and (3) a system for communication and coordination of care between all actors working in the zone of conflict, as collaboration between all medical actors is critical to the success of a surgical care system. Conclusions Ideally, the principles used to establish military and civilian trauma systems should be applied to the humanitarian care of patients in conflict zones. Organized trauma systems save lives and have become the standard of care; as such, it is vital for all actors to extend these benefits to populations in conflict.

Introduction In industrialized countries, mortality and disability-adjusted life-years attributable to blunt multiple trauma decreased markedly during the past decades. Advanced Trauma Life Support (ATLS), implementation of trauma centers and networks, hemostatic resuscitation, early pelvic stabilization, point-of-care ultrasonography, resuscitative endovascular balloon occlusion of the aorta, and other complex interventions contributed to this trend. Controversy exists about contrast-enhanced, whole-body computed tomography (WBCT) as a primary screening modality for suspected multiple trauma. Whole-body computed tomography shows excellent specificity but varying sensitivity for diagnosing injuries to different body areas. Apart from potential advantages on process quality, WBCT bears the risk of excessive exposure to diagnostic radiation. Modern scanner hardware and dose-sparing protocols have decreased radiation exposure with WBCT and, thus, the lifetime attributable risk of cancer. Recent noise-reducing image processing techniques, such as adaptive statistical iterative reconstruction (GE Healthcare) and iDose (Philips Healthcare), may further limit the radiation dose and likelihood of biological damage. In this study, we hypothesized that low-dose WBCT does not increase the risk of missed injury diagnoses at the point of care compared with standard-dose WBCT for screening patients with suspected blunt multiple trauma while exposing them to much less radiation.

it the radiation dose and likelihood of biological damage. In this study, we hypothesized that low-dose WBCT does not increase the risk of missed injury diagnoses at the point of care compared with standard-dose WBCT for screening patients with suspected blunt multiple trauma while exposing them to much less radiation. Methods Study Design and Setting This prospective time-series cohort study (Dose Reduction in Whole-Body Computed Tomography of Multiple Injuries [DoReMI]) was conducted at an academic urban trauma center in Berlin, Germany, accredited by the German Society for Trauma Surgery. The DoReMI study enrolled patients with suspected blunt multiple trauma scheduled for initial WBCT. This study was approved by the institutional review board (IRB) of the Charité Universitätsmedizin, Berlin, Germany, in November 2013. The IRB approved inclusion of unconscious and ventilated, hemodynamically unstable patients, conditional on establishing pathways to obtain written informed consent from the individual patient or the patient’s next of kin or legal representative. This study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline.

tilated, hemodynamically unstable patients, conditional on establishing pathways to obtain written informed consent from the individual patient or the patient’s next of kin or legal representative. This study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline. Selection of Participants Male and female patients of all ages with suspected blunt multiple trauma presenting to the emergency department and assigned to WBCT according to red flag criteria of the national evidence- and consensus-based best practice guideline for managing patients with severe injuries (Box) were eligible to participate in the study. Indication for WBCT matched international recommendations as summarized in recent systematic reviews. Patients were approached, informed about the study, and asked for consent to participate as soon as allowed by their physical and mental condition. Relatives, legal representatives, and patients were informed by physicians or professional clinical trial staff. Box. Inclusion and Exclusion Criteria Inclusion Criteria Suspected blunt multiple trauma resulting from the following: Car crash with extrication or death of ≥1 occupant Automobile vs pedestrian or bicycle Fall from a height greater than 10 ft (3 m) Any other high-velocity injury mechanism Resuscitation on scene or at the trauma bay by a multiprofessional team of paramedics and emergency physicians (including sedation or general anesthesia and airway management by orotracheal intubation)

Car crash with extrication or death of ≥1 occupant Automobile vs pedestrian or bicycle Fall from a height greater than 10 ft (3 m) Any other high-velocity injury mechanism Resuscitation on scene or at the trauma bay by a multiprofessional team of paramedics and emergency physicians (including sedation or general anesthesia and airway management by orotracheal intubation) Exclusion Criteria Patients considered unsuitable for WBCT for any reason (eg, need for immediate life-saving thoracotomy, laparotomy, or cranial trepanation before imaging) Patients declared dead on arrival or did not survive CPR Patients not allowed to take part because of refusal by their relatives or legal representatives Abbreviations: CPR, cardiopulmonary resuscitation; WBCT, whole-body computed tomography.

Exclusion Criteria Patients considered unsuitable for WBCT for any reason (eg, need for immediate life-saving thoracotomy, laparotomy, or cranial trepanation before imaging) Patients declared dead on arrival or did not survive CPR Patients not allowed to take part because of refusal by their relatives or legal representatives Abbreviations: CPR, cardiopulmonary resuscitation; WBCT, whole-body computed tomography. Intervention All patients were managed according to Pre-Hospital Trauma Life Support and ATLS principles by certified health care professionals or instructors, as mandated by the American College of Surgeons and the German Society for Trauma Surgery. After admission to the emergency department, patients were treated by an interdisciplinary team of trauma surgeons, anesthesiologists, radiologists, and nurses. This treatment included damage-control resuscitation, surgeon-performed focused ultrasonography of the thorax and abdomen, intubation and ventilation, relief of pneumothorax by chest tubes, and placement of central intravenous lines. At the investigational site, the CT suite is located opposite to the trauma bay. Patients were assigned to damage control or definitive surgery, intensive care, admission to a general trauma ward, or discharge and ambulatory care, according to their individual injury severity and pattern.

of central intravenous lines. At the investigational site, the CT suite is located opposite to the trauma bay. Patients were assigned to damage control or definitive surgery, intensive care, admission to a general trauma ward, or discharge and ambulatory care, according to their individual injury severity and pattern. All WBCT examinations were performed on a 128-row scanner (Philips Ingenuity Core; Philips Healthcare) in the standard-dose and low-dose study periods. All hardware and scanning protocols (including the iDose image processing algorithm) were approved by the US Food and Drug Administration and the European Medicines Agency. Patients were placed supine on the CT table with arms at their side. A low-dose scout imaging routine (Surview; Philips Healthcare) was followed for individual adjustment of scanning parameters. A native scan of the skull and midface was performed first, followed by contrast-enhanced whole-body imaging from the cranial base to the pelvis at the trochanteric level (eTable 1 in the Supplement). Automatic bolus tracking (BolusPro; Philips Healthcare) was used to trigger scans by placing a region of interest in the ascending aorta. Scanning was initiated 30 seconds after a predefined threshold of 120 Hounsfield units was reached. Images were stored in the local picture archiving and communication system (IntelliSpace PACS; Philips Healthcare).

o; Philips Healthcare) was used to trigger scans by placing a region of interest in the ascending aorta. Scanning was initiated 30 seconds after a predefined threshold of 120 Hounsfield units was reached. Images were stored in the local picture archiving and communication system (IntelliSpace PACS; Philips Healthcare). During the low-dose period, the iDose hybrid iterative reconstruction algorithm was used in adjunct to optimized tube energy and effective output. iDose is supposed to reduce noise and overcome inherent limitations of filtered back projection while maintaining the quality and usual clinical impression of CT images. Data Collection Data were collected from September 3, 2014, through August 20, 2016. All initial WBCT scans were read by board-certified radiologists, and findings were immediately reported to the trauma team in the initial (“hot”) report. For quality ascertainment, all primary scans were reread by the radiological consultant on call at the earliest opportunity, and results were presented during the next interdisciplinary morning (7:45 am) or afternoon (2:30 pm) trauma rounds. The local trial coordinating unit was responsible for data management, including data entry, plausibility checks, and query generation. Data were entered, stored, and processed using an electronic data capture system (secuTrial; interActive Systems). Data management complied with recent European General Data Protection Regulation.

ial coordinating unit was responsible for data management, including data entry, plausibility checks, and query generation. Data were entered, stored, and processed using an electronic data capture system (secuTrial; interActive Systems). Data management complied with recent European General Data Protection Regulation. Injuries were classified according to the Abbreviated Injury Scale coding scheme issued by the Association for the Advancement of Automotive Medicine as incorporated in recommendations by the American College of Surgeons and trained during ATLS courses. Patients enrolled during the standard-dose and low-dose periods were followed up in a similar fashion. A clinical synopsis using surgical reports and subsequent radiological examinations was used as an independent reference test to identify false-negative findings (missed diagnoses at the point of care) and false-positive findings (ie, injuries suspected by initial reading that could not be reproduced during follow-up). After discharge, any information about outpatient visits, reports by rehabilitation facilities, and private practice health care professionals was collected to identify false-negative or false-positive findings of the initial WBCT examination. Because lethal injuries are considered nonnatural causes of death in Germany, corpses of injured patients are confiscated by prosecution officers. However, forensic autopsies for research purposes are difficult to obtain.

Injuries were classified according to the Abbreviated Injury Scale coding scheme issued by the Association for the Advancement of Automotive Medicine as incorporated in recommendations by the American College of Surgeons and trained during ATLS courses. Patients enrolled during the standard-dose and low-dose periods were followed up in a similar fashion. A clinical synopsis using surgical reports and subsequent radiological examinations was used as an independent reference test to identify false-negative findings (missed diagnoses at the point of care) and false-positive findings (ie, injuries suspected by initial reading that could not be reproduced during follow-up). After discharge, any information about outpatient visits, reports by rehabilitation facilities, and private practice health care professionals was collected to identify false-negative or false-positive findings of the initial WBCT examination. Because lethal injuries are considered nonnatural causes of death in Germany, corpses of injured patients are confiscated by prosecution officers. However, forensic autopsies for research purposes are difficult to obtain. Outcome Measures A missed injury diagnosis at the point of care was defined as any injury demanding clinical awareness or therapeutic action at any time but that was not recognized in the initial WBCT or contained in the hot report provided to the trauma team. These diagnoses may be revealed during a second independent reading of the original scan. The DoReMI study was initiated ahead of the Berlin definition of multiple trauma incorporating physiological parameters in addition to an anatomical organ injury scale score. Multiple trauma was then indicated by the presence of injuries to 2 or more body regions that, alone or in combination, were life threatening or resulted in an Injury Severity Score of greater than 15.

ition of multiple trauma incorporating physiological parameters in addition to an anatomical organ injury scale score. Multiple trauma was then indicated by the presence of injuries to 2 or more body regions that, alone or in combination, were life threatening or resulted in an Injury Severity Score of greater than 15. False-negative and false-positive findings may be caused by misinterpretation by the first reader or technical limitations to detect injuries. In the real world, it makes no difference whether a certain injury was missed or falsely presumed because of the reader’s fault or technical reasons, and the initial diagnostic information provided to the trauma team was accepted as the index test finding. Dosimetry indexes were calculated automatically using section thickness, number of sections, and dose. This calculation included the volume CT dose index, dose-length product (DLP), and size-specific dose estimate. The CT dose index represents the energy dose (in milligrays) absorbed in a presumed rectangle profile of a single section with thickness provided by the manufacturer. The DLP accounts for the length of the scan, expressed as milligrays per centimeter. The size-specific dose estimates are adjusted for individual patient sizes and expressed as milligrays. Subjective image quality among different tissues and sites was graded by 2 independent radiologists (F.R. and T.K.) using a 100-mm visual analog scale, with 0 indicating worst and 100 indicating perfect quality. Ratings were made in a paper-based fashion and subsequently entered in the electronic data capture system.

Dosimetry indexes were calculated automatically using section thickness, number of sections, and dose. This calculation included the volume CT dose index, dose-length product (DLP), and size-specific dose estimate. The CT dose index represents the energy dose (in milligrays) absorbed in a presumed rectangle profile of a single section with thickness provided by the manufacturer. The DLP accounts for the length of the scan, expressed as milligrays per centimeter. The size-specific dose estimates are adjusted for individual patient sizes and expressed as milligrays. Subjective image quality among different tissues and sites was graded by 2 independent radiologists (F.R. and T.K.) using a 100-mm visual analog scale, with 0 indicating worst and 100 indicating perfect quality. Ratings were made in a paper-based fashion and subsequently entered in the electronic data capture system. Objective image quality was assessed by the contrast-to-noise ratio. Standard regions of interest were placed in 7 anatomical landmarks: carotid artery, aortic arch, liver parenchyma, kidney cortex, abdominal aorta, cervical spine vertebra (C7), and lumbar spine vertebra (L1). The reference region of interest was placed in muscle tissue adjacent to the individual landmark on the same cross-sectional image.

interest were placed in 7 anatomical landmarks: carotid artery, aortic arch, liver parenchyma, kidney cortex, abdominal aorta, cervical spine vertebra (C7), and lumbar spine vertebra (L1). The reference region of interest was placed in muscle tissue adjacent to the individual landmark on the same cross-sectional image. Statistical Analysis and Sample Size Calculation Data were analyzed January 16, 2017, through October 14, 2019. At the time of planning and commencing this study, 3 previous investigations had specifically determined the risk of missed injuries with standard-dose WBCT in major trauma (including 1534 patients, 186 of whom had missed injuries). The pooled overall risk (using a random-effects model because of significant heterogeneity across studies, implemented in the STATA metaprop module [StataCorp LLC]) was 21% (95% CI, 7%-35% [eFigure 1 in the Supplement]). No reliable prior evidence was available to define noninferiority margins in categorical end points between the specific interventions of interest. Because of the quasi-experimental design of this study and lack of noninferiority margins, we did not use inferential statistics to test for noninferiority of low-dose compared with standard-dose WBCT. We attempted high precision of estimates and tight confidence intervals to substantiate our primary objective that low-dose WBCT does not increase the risk of missed injury diagnoses in a clinically meaningful or statistically significant manner compared with standard-dose WBCT. We aimed at a cohort size in which upper 97.5% binomial-exact confidence limits of the risk difference (RD) did not exceed 5% of the point estimate, given a baseline risk of missed injuries of 20% and varying scenarios with RDs of 4%, 2%, and 1% (eFigure 2 in the Supplement). This was guaranteed with a minimum sample size of 450 evaluable patients per group. To account for postallocation dropouts because of lack or denial of informed consent, missing data, and other sources of information loss, we aimed at enrolling 500 consecutive patients each in the standard-dose and low-dose WBCT periods. This approach was approved by the IRB and stated in the published trial protocol.

To account for postallocation dropouts because of lack or denial of informed consent, missing data, and other sources of information loss, we aimed at enrolling 500 consecutive patients each in the standard-dose and low-dose WBCT periods. This approach was approved by the IRB and stated in the published trial protocol. Results are presented as means, medians, proportions, differences in means and proportions, RDs, and odds ratios (ORs), including measures of distribution and precision, such as SD, interquartile range (IQR), and 95% CI. The primary outcome, the proportion of patients with at least 1 missed injury diagnosis, was analyzed by a segmented regression model. This model assumes that, apart from seasonal fluctuation of events as operationalized by time intervals (ie, months), there is no bias by confounding variables. Autocorrelation was assessed by the Durbin-Watson statistic. We performed a secondary multivariate logistic regression analysis, adjusting OR of missed injury diagnoses at the point of care for age, sex, intubation, shock, coagulation measures, positive findings of focused ultrasonography of the thorax and abdomen, and the interval from admission to WBCT. Prevalence, sensitivity, and specificity for excluding and confirming injuries with 95% CI were calculated using cross-tables. Complications, adverse events, and serious adverse events were recorded for either protocol. Medians and skewed continuous measures were compared by the Kruskal-Wallis test.

Results are presented as means, medians, proportions, differences in means and proportions, RDs, and odds ratios (ORs), including measures of distribution and precision, such as SD, interquartile range (IQR), and 95% CI. The primary outcome, the proportion of patients with at least 1 missed injury diagnosis, was analyzed by a segmented regression model. This model assumes that, apart from seasonal fluctuation of events as operationalized by time intervals (ie, months), there is no bias by confounding variables. Autocorrelation was assessed by the Durbin-Watson statistic. We performed a secondary multivariate logistic regression analysis, adjusting OR of missed injury diagnoses at the point of care for age, sex, intubation, shock, coagulation measures, positive findings of focused ultrasonography of the thorax and abdomen, and the interval from admission to WBCT. Prevalence, sensitivity, and specificity for excluding and confirming injuries with 95% CI were calculated using cross-tables. Complications, adverse events, and serious adverse events were recorded for either protocol. Medians and skewed continuous measures were compared by the Kruskal-Wallis test. Reliability of subjective ratings was assessed by the intraclass correlation coefficient using a 2-way random-effects model. Substantial reliability was assumed with an intraclass correlation coefficient of 0.4 or higher for all 7 rated areas. We used SPSS, version 25.0 (IBM Corporation) and STATA, version 14.2 (Stata Corp LLC) for statistical analysis. P values were used with 95% CIs in an explanatory fashion.

a 2-way random-effects model. Substantial reliability was assumed with an intraclass correlation coefficient of 0.4 or higher for all 7 rated areas. We used SPSS, version 25.0 (IBM Corporation) and STATA, version 14.2 (Stata Corp LLC) for statistical analysis. P values were used with 95% CIs in an explanatory fashion. Results Of 1695 patients screened, 1074 patients or their legal representatives consented to participate in the study. From September 3, 2014, through July 26, 2015, 565 patients underwent standard-dose WBCT, followed by 509 patients undergoing low-dose WBCT from August 7, 2015, through August 20, 2016. Altogether, data from 971 patients were available for primary end point analysis, with losses due to lacking information to compute a reference test (Figure 1). Among the 971 patients included in the analysis, mean (SD) age was 52.7 (19.5) years; 649 (66.8%) were men and 322 (33.2%) were women. One hundred fourteen patients (11.7%; 95% CI, 9.8%-13.9%) had multiple trauma. Baseline demographics for the 2 groups were similar (Table). Patients in the low-dose protocol period had a marginally higher mean (SD) international normalized ratio (1.3 [0.7] vs 1.2 [0.4]) and maximal Abbreviated Injury Scale score of the abdomen (2.4 [0.8] vs 2.1 [0.7]) and pelvis (2.4 [0.9] vs 2.2 [0.8]). Ultimate consequences from WBCT imaging and disposition of patients from the emergency department are shown in eTable 2 in the Supplement. Figure 1. Study Profile and Flowchart WBCT indicates whole-body computed tomography.

Results Of 1695 patients screened, 1074 patients or their legal representatives consented to participate in the study. From September 3, 2014, through July 26, 2015, 565 patients underwent standard-dose WBCT, followed by 509 patients undergoing low-dose WBCT from August 7, 2015, through August 20, 2016. Altogether, data from 971 patients were available for primary end point analysis, with losses due to lacking information to compute a reference test (Figure 1). Among the 971 patients included in the analysis, mean (SD) age was 52.7 (19.5) years; 649 (66.8%) were men and 322 (33.2%) were women. One hundred fourteen patients (11.7%; 95% CI, 9.8%-13.9%) had multiple trauma. Baseline demographics for the 2 groups were similar (Table). Patients in the low-dose protocol period had a marginally higher mean (SD) international normalized ratio (1.3 [0.7] vs 1.2 [0.4]) and maximal Abbreviated Injury Scale score of the abdomen (2.4 [0.8] vs 2.1 [0.7]) and pelvis (2.4 [0.9] vs 2.2 [0.8]). Ultimate consequences from WBCT imaging and disposition of patients from the emergency department are shown in eTable 2 in the Supplement. Figure 1. Study Profile and Flowchart WBCT indicates whole-body computed tomography. Table. Patient Characteristics Characteristic WBCT Group P Value Standard-Dose (n = 468) Low-Dose (n = 503) Age, mean (SD), y 52.9 (18.9) 52.5 (20.0) .78 Male sex, No. (%) 312 (66.7) 337 (67.0) .95 Mechanism of injury, No. (%) MVC 117 (25.0) 120 (23.9) .81 Motorcycle 67 (14.3) 69 (13.7) Fall 198 (42.3) 200 (39.8) Auto vs pedestrian 22 (4.7) 28 (5.6) Cyclist 31 (6.6) 38 (7.6) Assault 7 (1.5) 10 (2.0) Other 26 (5.6) 38 (7.6) Transport or transfer, No. (%) Helicopter 123 (26.3) 141 (28.0) .06 Ground ambulance Paramedics 116 (24.8) 134 (26.6) Physician staff 194 (41.5) 200 (39.8) Walk-in 25 (5.3) 27 (5.4) Other 10 (2.1) 1 (0.2) Orotracheal intubation, No. (%) 95 (20.3) 94 (18.7) .57 Shock index, mean (SD)a 0.7 (0.4) 0.7 (0.3) .97 Hemoglobin level, mean (SD), g/dLb 13.4 (2.2) 13.4 (2.1) .95 INR, mean (SD)c 1.2 (0.4) 1.3 (0.7) .048 PTT, mean (SD), sc 35.2 (18.5) 35.1 (21.6) .96 Multiple trauma with ISS >15, No. (%)d 55 (12) 59 (12) >.99 Maximal AIS score, mean (SD)e Head and neckf 2.4 (1.4) 2.3 (1.3) .17 Faceg 1.7 (0.8) 1.6 (0.8) .39 Thoraxh 2.2 (1.0) 2.4 (1.1) .33 Abdomeni 2.1 (0.7) 2.4 (0.8) .007 Extremitiesj 2.2 (0.8) 2.4 (0.9) .049 Externalk 1.3 (0.7) 1.3 (0.7) .80 Abbreviations: AIS, Abbreviated Injury Scale; INR, international normalized ratio; ISS, Injury Severity Score; MVC, motor vehicle crash; PTT, partial thromboplastin time; WBCT, whole-body computed tomography.

) .33 Abdomeni 2.1 (0.7) 2.4 (0.8) .007 Extremitiesj 2.2 (0.8) 2.4 (0.9) .049 Externalk 1.3 (0.7) 1.3 (0.7) .80 Abbreviations: AIS, Abbreviated Injury Scale; INR, international normalized ratio; ISS, Injury Severity Score; MVC, motor vehicle crash; PTT, partial thromboplastin time; WBCT, whole-body computed tomography. SI conversion factor: To convert hemoglobin to grams per liter, multiply by 10.0. a Based on 923 (426 and 497) patients, accounting for missing data. Calculated as heart rate in beats per minute divided by systolic blood pressure in millimeters of mercury. b Based on 968 (465 and 503) patients, accounting for missing data. c Based on 961 (459 and 502) patients, accounting for missing data. d Indicates major trauma. e Scores range from 0 to 6, with 6 indicating maximum severity. f Based on 455 (210 and 245) patients with head and neck injuries. g Based on 85 (30 and 55) patients with facial trauma. h Based on 153 (73 and 80) patients with thoracic injuries. i Based on 168 (77 and 91) patients with abdominal injuries. j Based on 228 (121 and 107) patients with fractures of the pelvis or extremities. k Based on 61 (37 and 24) patients with skin and soft tissue injuries.

f Based on 455 (210 and 245) patients with head and neck injuries. g Based on 85 (30 and 55) patients with facial trauma. h Based on 153 (73 and 80) patients with thoracic injuries. i Based on 168 (77 and 91) patients with abdominal injuries. j Based on 228 (121 and 107) patients with fractures of the pelvis or extremities. k Based on 61 (37 and 24) patients with skin and soft tissue injuries. The incidence of missed diagnoses fluctuated over time (eFigure 3 in the Supplement). By segmented regression analysis, the period of observation (β = −0.002; P = .83), implementation of the low-dose algorithm (β = 0.056; P = .50), and the interval after implementation (β = −0.007, P = .58) did not influence the risk of missed diagnoses. The Durbin-Watson statistic (d = 2.323) suggested no significant autocorrelation. Altogether, 109 of 468 patients in the standard-dose WBCT group (23.3%) and 107 of 503 patients in the low-dose WBCT group (21.3%) had any missed injury diagnosis at the point of care (RD, −2.0% [95% CI, −7.3% to 3.2%]; unadjusted OR, 0.89 [95% CI, 0.66-1.20]; P = .45). Among patients with any serious injury classified as 3 or greater on the Abbreviated Injury Scale (n = 411) (6 indicates maximum severity), 71 of 193 patients in the standard-dose WBCT group (36.8%) and 74 of 218 in the low-dose WBCT group (33.9%) had missed injury diagnoses (RD, −2.8% [95% CI, −12.1% to 6.4%]; unadjusted OR, 0.88 [95% CI, 0.59-1.32]; P = .55). Multivariable logistic regression showed no differences between raw and adjusted estimates in the OR of missed injuries in different anatomical regions (Figure 2).

The incidence of missed diagnoses fluctuated over time (eFigure 3 in the Supplement). By segmented regression analysis, the period of observation (β = −0.002; P = .83), implementation of the low-dose algorithm (β = 0.056; P = .50), and the interval after implementation (β = −0.007, P = .58) did not influence the risk of missed diagnoses. The Durbin-Watson statistic (d = 2.323) suggested no significant autocorrelation. Altogether, 109 of 468 patients in the standard-dose WBCT group (23.3%) and 107 of 503 patients in the low-dose WBCT group (21.3%) had any missed injury diagnosis at the point of care (RD, −2.0% [95% CI, −7.3% to 3.2%]; unadjusted OR, 0.89 [95% CI, 0.66-1.20]; P = .45). Among patients with any serious injury classified as 3 or greater on the Abbreviated Injury Scale (n = 411) (6 indicates maximum severity), 71 of 193 patients in the standard-dose WBCT group (36.8%) and 74 of 218 in the low-dose WBCT group (33.9%) had missed injury diagnoses (RD, −2.8% [95% CI, −12.1% to 6.4%]; unadjusted OR, 0.88 [95% CI, 0.59-1.32]; P = .55). Multivariable logistic regression showed no differences between raw and adjusted estimates in the OR of missed injuries in different anatomical regions (Figure 2). Figure 2. Unadjusted and Adjusted Odds Ratios (ORs) of Missed Injury Diagnoses Adjustment was made using a multivariable logistic regression model, accounting for age, sex, intubation, heart rate, systolic blood pressure, hemoglobin concentration, international normalized ratio and partial thromboplastin time on admission, a positive finding of thoracoabdominal focused ultrasonographic scan at the trauma bay, and the interval from admission to whole-body computed tomography. AIS indicates Abbreviated Injury Scale score (1 indicates minor and 6, maximum).

ration, international normalized ratio and partial thromboplastin time on admission, a positive finding of thoracoabdominal focused ultrasonographic scan at the trauma bay, and the interval from admission to whole-body computed tomography. AIS indicates Abbreviated Injury Scale score (1 indicates minor and 6, maximum). Ratings of subjective image quality varied across observers and region of interest (eFigure 4 in the Supplement). Both WBCT protocols showed high specificity in detecting injuries in various body areas (eTable 3 in the Supplement). Sensitivity, however, varied markedly across anatomical regions and was particularly low in case of hemothorax, hollow visceral tears, hemoperitoneum, retroperitoneal bleeding, and kidney injuries (eTable 4 in the Supplement). Low-dose WBCT significantly decreased exposure to radiation (Figure 3). Median volume CT dose index was reduced from 11.7 (IQR, 11.7-17.6) to 5.9 (IQR, 5.9-8.8) mGy (P < .001). Median DLP was reduced from 1109 (IQR, 1020-1578) to 735 (IQR, 525-847) mGy/cm (P < .001). Median size-specific dose estimate was reduced from 16.4 (IQR, 14.5-18.6) to 8.8 (IQR, 7.7-10.6; P < .001) at midbody and from 16.2 (IQR, 14.1-18.2) to 8.7 (IQR, 7.4-10.3; P < .001) at navel level.

(IQR, 5.9-8.8) mGy (P < .001). Median DLP was reduced from 1109 (IQR, 1020-1578) to 735 (IQR, 525-847) mGy/cm (P < .001). Median size-specific dose estimate was reduced from 16.4 (IQR, 14.5-18.6) to 8.8 (IQR, 7.7-10.6; P < .001) at midbody and from 16.2 (IQR, 14.1-18.2) to 8.7 (IQR, 7.4-10.3; P < .001) at navel level. Figure 3. Dose Estimates of Standard-Dose and Low-Dose Whole-Body Computed Tomographic (WBCT) Scans The low-dose protocol used the iDose image processing algorithm. Data are expressed as medians and interquartile range (error bars). Circles represent outliers. For better readability, single extreme outliers are not shown for the standard-dose group (computed tomographic dose index [CTDI] volume, 1174 mGy; dose-length product [DLP] 33063.1 mGy/cm; size-specific dose estimate [SSDE] midbody, 1801.6 mGy; SSDE navel, 1823.6 mGy) or the low-dose group (CTDI volume, 585 mGy; DLP, 5021.1 mGy/cm; SSDE midbody, 891.9 mGy; SSDE navel, 866.8 mGy).

or the standard-dose group (computed tomographic dose index [CTDI] volume, 1174 mGy; dose-length product [DLP] 33063.1 mGy/cm; size-specific dose estimate [SSDE] midbody, 1801.6 mGy; SSDE navel, 1823.6 mGy) or the low-dose group (CTDI volume, 585 mGy; DLP, 5021.1 mGy/cm; SSDE midbody, 891.9 mGy; SSDE navel, 866.8 mGy). The contrast-to-noise ratio consistently favored low-dose WBCT for all investigated anatomical regions (eFigure 5 in the Supplement). Median contrast-to-noise ratio was 28.9 (IQR, 16.8-43.8) vs 11.7 (IQR, 9.0-17.1) in the carotid artery (P < .001), 17.8 (IQR, 13.7-24.2) vs 15.1 (IQR, 10.7-19.6) in the aortic arch (P < .001), 2.5 (IQR, 1.4-3.5) vs 2.0 (IQR, 1.2-2.9) in the liver (P < .001), 9.8 (IQR, 7.2-13.2) vs 8.3 (IQR, 5.7-11.0) in the kidney (P < .001), 13.1 (IQR, 9.3-19.1) vs 11.6 (IQR, 7.7-16.4) in the aorta (P < .001), 7.4 (IQR, 5.6-9.7) vs 4.7 (IQR, 3.5-6.4) in the seventh cervical vertebral (P < .001), and 5.9 (IQR, 4.1-8.8) vs 4.2 (IQR, 2.8-6.5) in the first lumbar vertebral (P < .001). Four adverse events occurred (ie, extravasates of intravenously admitted contrast agent), with 3 (0.6%) and 1 (0.2%) incidents occurring in either group (P = .28). No other intervention-related events compromising patients’ safety were observed during the study.

(IQR, 2.8-6.5) in the first lumbar vertebral (P < .001). Four adverse events occurred (ie, extravasates of intravenously admitted contrast agent), with 3 (0.6%) and 1 (0.2%) incidents occurring in either group (P = .28). No other intervention-related events compromising patients’ safety were observed during the study. Discussion In this prospective time-series cohort study, low-dose WBCT using statistical image reconstruction did not increase the risk of missed injury diagnoses at the point of care in patients with suspected blunt multiple trauma compared with standard-dose WBCT scanning. Low-dose WBCT almost halved radiation exposure and improved the contrast-to-noise ratio compared with standard-dose imaging, while maintaining diagnostic accuracy. Conflicting evidence about the effect of primary WBCT on patient outcomes in major trauma is available. The only randomized clinical trial at present failed to show a difference in raw mortality between both diagnostic options, whereas large-scale registries suggest a significantly decreased risk-adjusted ratio of observed to expected deaths with primary WBCT. Excess radiation remains a major concern and obstacle to the liberal use of primary WBCT in trauma resuscitation.

to show a difference in raw mortality between both diagnostic options, whereas large-scale registries suggest a significantly decreased risk-adjusted ratio of observed to expected deaths with primary WBCT. Excess radiation remains a major concern and obstacle to the liberal use of primary WBCT in trauma resuscitation. The observed rate of missed diagnoses in this study markedly exceeded that from a recent French investigation that included 2354 scans in patients with trauma obtained at 26 sites during a 5-year period (12.9%; 95% CI, 11.6%-14.3%) and other studies. Strict independent confirmation of positive and negative index test results may explain the rather high frequency of missed injury diagnoses compared with previous studies that calculated the risk by a secondary review of initial scans. A review of all subsequent clinical, surgical, and imaging findings was considered the most appropriate (though still imperfect) diagnostic reference test to verify initial WBCT results, because it would be unsuitable and unethical to assign patients to a second WBCT, magnetic resonance imaging, or even invasive procedures to confirm index test findings.

surgical, and imaging findings was considered the most appropriate (though still imperfect) diagnostic reference test to verify initial WBCT results, because it would be unsuitable and unethical to assign patients to a second WBCT, magnetic resonance imaging, or even invasive procedures to confirm index test findings. Limitations Although this study was originally planned as a noninferiority randomized clinical trial, the IRB prohibited random allocation of patients to either imaging strategy. The IRB’s ethical logic was that no previous experimental data had demonstrated that low-dose WBCT does not pose any extra risk of missed injury diagnoses to patients compared with standard-dose WBCT. The ultimate risk of a missed injury diagnosis by low-dose WBCT was considered more important than the remote lifetime attributable risk of cancer by standard-dose WBCT. The IRB approved this controlled, quasi-confirmatory before-and-after study, and several statistical efforts were made to control primary end points for time-dependent patient- and intervention-related variables. The baseline profile was well balanced among groups, and there was no marked association of injury-related or other variables with effect estimates. Conservative definitions of missed injuries were used, because blunt trauma minor injuries or their combination may be detrimental in the long term. This, however, may have led to an overestimate of the incidence of missed injuries and an underestimate of the sensitivity of WBCT with either dose protocol. Radiation exposure was determined by volume CT dose index, DLP, and size-specific dose estimate rather than effective doses. Patient- and organ-specific dose estimates depend on conversion factors specific to individual health care systems and different estimation methods (eg, Monte-Carlo simulation). However, volume CT dose index and DLP are valid measures to compare radiation exposure between different WBCT protocols. Although objective image quality was better with the low-dose protocol, subjective image quality varied considerably among regions of interest.

ferent estimation methods (eg, Monte-Carlo simulation). However, volume CT dose index and DLP are valid measures to compare radiation exposure between different WBCT protocols. Although objective image quality was better with the low-dose protocol, subjective image quality varied considerably among regions of interest. Conclusions The findings of this study suggest that low-dose WBCT may safely replace standard-dose WBCT in diagnostic workup of blunt multiple trauma. It provided comparable diagnostic accuracy at a much lower radiation dose and was not associated with extra harms. Because this was a quasi-experimental study, a large-scale, multicenter randomized clinical trial is warranted to confirm our findings. Supplement. eTable 1. CT Scanning Parameters eTable 2. Therapeutic Consequences From WBCT eTable 3. Diagnostic Accuracy Among Different Anatomical Regions eTable 4. Accuracy of WBCT in Diagnosing Individual Injuries eFigure 1. Meta-analysis of Studies Reporting on Missed Injuries With WBCT eFigure 2. Sample Size Calculation With Different Clinical Scenarios eFigure 3. Incidence of Missed Injury Diagnoses Over Time eFigure 4. Subjective Rating of Image Quality by 2 Independent Observers Using a 100-mm Visual Analog Scale (VAS) eFigure 5. Contrast-to-Noise Ratio (CNR) in Different Regions of Interest (ROI) Click here for additional data file.

erial19; (4) use of perioperative goal-directed fluid therapy (GDFT) to guide fluid resuscitation20; (5) admission of all patients to the intensive care unit after a surgical procedure9,21; and (6) involvement of senior clinicians in the decision to proceed to surgical treatment and throughout the surgical procedure.13 The aim of this study was to assess whether a quality improvement (QI) collaborative approach to implement a care bundle for patients undergoing emergency laparotomy across a large hospital group could be associated with a reduction in unadjusted and P-POSSUM risk-adjusted in-hospital mortality capped at 30 days, reduction in inpatient length of stay (LOS), and improvement in the delivery of agreed-on quality standards of care.

Introduction Emergency general surgery occurs commonly,1 and patients undergoing major nontrauma nonvascular intra-abdominal operation or emergency laparotomy form a specific subset of emergency general surgical patients. Mortality and morbidity rates are high for patients undergoing emergency laparotomy, with reports from the United Kingdom,2,3,4 United States,5 and Denmark6 suggesting a 30-day mortality of between 10% and 18%. In a UK study3 carried out over 3 months, crude 30-day mortality for emergency laparotomy across 27 hospitals varied between 3% and 45%. These mortality figures are substantially higher than the mortality rates for elective surgical procedures for which in-hospital mortality rates of 1% to 2% are usually reported for even the most complex procedures.7 To date, few studies exist to improve outcomes for patients requiring emergency laparotomy.

3% and 45%. These mortality figures are substantially higher than the mortality rates for elective surgical procedures for which in-hospital mortality rates of 1% to 2% are usually reported for even the most complex procedures.7 To date, few studies exist to improve outcomes for patients requiring emergency laparotomy. Underlying the observed wide variation in mortality are considerable differences in the patients undergoing emergency laparotomy and in the delivery of their care.8 Although it may be difficult to control for patient variation at presentation, evidence highlights the wide variation in delivering key aspects of care.4,8,9,10,11 This variation includes inconsistencies in initiating prompt patient resuscitation, management of common acute physiologic changes,12 communication between professionals, understanding of patient risk,8 use of perioperative goal-directed fluid resuscitation,3 admission of patients after a surgical procedure to the intensive care unit,5 and involvement by senior surgeons and anesthesiologists in the care of patients.2 In the United Kingdom, the Royal College of Surgeons of England attempted to define standards of care that should be considered for the management of patients undergoing emergency laparotomy.13 In addition, the national Healthcare Quality Improvement Partnership funded a mandatory audit, the National Emergency Laparotomy Audit (NELA), to record the delivery of key process measures and outcomes for all patients in England and Wales who undergo emergency laparotomy.2

patients undergoing emergency laparotomy.13 In addition, the national Healthcare Quality Improvement Partnership funded a mandatory audit, the National Emergency Laparotomy Audit (NELA), to record the delivery of key process measures and outcomes for all patients in England and Wales who undergo emergency laparotomy.2 With the aim of reducing mortality for emergency laparotomy, a group of 4 hospitals in England used a care bundle approach to implement the standards of care recommended for the higher-risk surgical patient.13 The results showed a 25% reduction in crude 30-day mortality and a 42% reduction in the Portsmouth Physiological and Operative Severity Score for the enumeration of Mortality and morbidity (P-POSSUM)14 risk-adjusted mortality at 30 days.15 Supporting these improvements in outcome were similar substantial improvements in delivery in many key processes of care. Two further studies16,17 from Denmark used a similar approach with more than 700 patients and showed a similar 25% reduction in crude hospital mortality.

SUM)14 risk-adjusted mortality at 30 days.15 Supporting these improvements in outcome were similar substantial improvements in delivery in many key processes of care. Two further studies16,17 from Denmark used a similar approach with more than 700 patients and showed a similar 25% reduction in crude hospital mortality. The 3 studies15,16,17 used a number of evidence-based standards of care that, when consistently delivered, brought about substantial improvements in patient outcomes. These standards of care include the (1) use of an early warning score18 or blood lactate level measurement to aid immediate resuscitation and escalation; (2) early identification of sepsis and early administration of broad-spectrum antibiotics, as recommended by the Surviving Sepsis Campaign19; (3) early transfer to the operating room (OR) to carry out definitive surgical treatment and drainage and removal of septic material19; (4) use of perioperative goal-directed fluid therapy (GDFT) to guide fluid resuscitation20; (5) admission of all patients to the intensive care unit after a surgical procedure9,21; and (6) involvement of senior clinicians in the decision to proceed to surgical treatment and throughout the surgical procedure.13

re bundle for patients undergoing emergency laparotomy across a large hospital group could be associated with a reduction in unadjusted and P-POSSUM risk-adjusted in-hospital mortality capped at 30 days, reduction in inpatient length of stay (LOS), and improvement in the delivery of agreed-on quality standards of care. Methods This study was a QI project in the United Kingdom, called the Emergency Laparotomy Collaborative (ELC), involving 28 National Health Service hospitals with inpatient bed capacity between 246 and 1300. The ELC design was based on an Institute for Healthcare Improvement Breakthrough Series collaborative approach22 of hospital teams meeting every 3 months. Between these meetings, the teams were supported by improvement teams from 3 local Academic Health Science Network groups.23 The care bundle implemented is shown in the Box. An assessment of the study was completed to determine its alignment with national guidance,24 which confirmed the project fell outside the area of research and required no further ethical approvals or informed consent. Data from the NELA were collected by each participating ELC hospital with national ethical approval for that data set. Each hospital was asked to register its participation in the project with its own research and development panel. Box. How to Save Lives in Emergency Laparotomy Screen patient NEWS/SIRS/arterial lactate level Assess whether patient has signs of sepsis Treat with antibiotics within 1 h Move patient to operating room Move to operating room within 6 h of decision to operate Consultant surgeon and anesthesiologist

Methods This study was a QI project in the United Kingdom, called the Emergency Laparotomy Collaborative (ELC), involving 28 National Health Service hospitals with inpatient bed capacity between 246 and 1300. The ELC design was based on an Institute for Healthcare Improvement Breakthrough Series collaborative approach22 of hospital teams meeting every 3 months. Between these meetings, the teams were supported by improvement teams from 3 local Academic Health Science Network groups.23 The care bundle implemented is shown in the Box. An assessment of the study was completed to determine its alignment with national guidance,24 which confirmed the project fell outside the area of research and required no further ethical approvals or informed consent. Data from the NELA were collected by each participating ELC hospital with national ethical approval for that data set. Each hospital was asked to register its participation in the project with its own research and development panel. Box. How to Save Lives in Emergency Laparotomy Screen patient NEWS/SIRS/arterial lactate level Assess whether patient has signs of sepsis Treat with antibiotics within 1 h Move patient to operating room Move to operating room within 6 h of decision to operate Consultant surgeon and anesthesiologist In operating room Monitor cardiac output Goal-directed fluid therapy ICU for all patients Abbreviations: ICU, intensive care unit; NEWS, National Early Warning Score; SIRS, Systemic Inflammatory Response Syndrome. Adapted from the Emergency Laparotomy Collaborative.

Move to operating room within 6 h of decision to operate Consultant surgeon and anesthesiologist In operating room Monitor cardiac output Goal-directed fluid therapy ICU for all patients Abbreviations: ICU, intensive care unit; NEWS, National Early Warning Score; SIRS, Systemic Inflammatory Response Syndrome. Adapted from the Emergency Laparotomy Collaborative. The hospitals were located across the south of England. All consecutive patients who underwent emergency laparotomy were included. Patients were followed up for a maximum of 30 days after the surgical procedure or until discharge or death if this occurred before 30 days. No patient selection or grouping was carried out other than using the inclusion and exclusion criteria as identified in the NELA data set during the study period.2 A multidisciplinary local implementation group was formed in each hospital, and the group included general surgeons, anesthesiologists, intensivists, nurses, and QI specialists. Hospitals submitted their anonymized NELA data set for the 15 months preceding the start of the project to act as their own baseline. After the launch of the project on October 1, 2015, hospitals submitted their ongoing anonymized NELA data to a central database every 3 months for the following 24 months of the project.

ospitals submitted their anonymized NELA data set for the 15 months preceding the start of the project to act as their own baseline. After the launch of the project on October 1, 2015, hospitals submitted their ongoing anonymized NELA data to a central database every 3 months for the following 24 months of the project. The ELC project had a leadership board composed of clinicians, QI experts, data analysts, and program managers. This group met regularly throughout the life of the project. The 24-month program of QI included clinical evidence review, QI methodology, leadership and negotiation coaching, promotion of collaborative learning and sharing of new ideas, and sustainability development. The model for improvement25 was used to coach teams on the plan-do-study-act cycles. This teaching was combined with other elements such as systems analysis, driver diagrams, and performance monitoring using time series data. To help hospitals own their real-time data, teaching on data use and analysis was provided. Coaching was also provided to assist teams to promote behavioral change.26 The second 12-month period focused on leadership and negotiation skills. Data on adherence to the 6-point care bundle were prospectively collected for each patient undergoing emergency laparotomy. Aggregate quarterly performance data for each hospital were shared across the collaborative group in the form of run charts and a comparative dashboard.

The model for improvement25 was used to coach teams on the plan-do-study-act cycles. This teaching was combined with other elements such as systems analysis, driver diagrams, and performance monitoring using time series data. To help hospitals own their real-time data, teaching on data use and analysis was provided. Coaching was also provided to assist teams to promote behavioral change.26 The second 12-month period focused on leadership and negotiation skills. Data on adherence to the 6-point care bundle were prospectively collected for each patient undergoing emergency laparotomy. Aggregate quarterly performance data for each hospital were shared across the collaborative group in the form of run charts and a comparative dashboard. The primary outcomes were in-hospital (truncated at 30 days) mortality, both crude and P-POSSUM risk-adjusted, and LOS. The secondary outcomes were the changes after implementation of the separate metrics in the care bundle. Baseline data were collected from July 1, 2014, to September 30, 2015 (months 1 to 15), and prospective (post-ELC implementation) data were obtained from October 1, 2015, to September 30, 2017 (months 16 to 39).

The primary outcomes were in-hospital (truncated at 30 days) mortality, both crude and P-POSSUM risk-adjusted, and LOS. The secondary outcomes were the changes after implementation of the separate metrics in the care bundle. Baseline data were collected from July 1, 2014, to September 30, 2015 (months 1 to 15), and prospective (post-ELC implementation) data were obtained from October 1, 2015, to September 30, 2017 (months 16 to 39). Statistical Analysis Initially, the statistical significance of changes, pre-ELC compared with post-ELC, in continuous variables (age, blood lactate level, systolic blood pressure, serum creatinine level, Glasgow Coma Scale score [score range: 1-15, with the highest score indicating complete consciousness], number of patients per month) was assessed using linear regression models. Likewise, quantile (P-POSSUM risk), logistic (male and type of operation), and ordinal (American Society of Anaesthesiologists physical status grade) regression models were used for other variables. Two-sided P values were obtained from specific statistical models, for which P < .05 was statistically significant.

dels. Likewise, quantile (P-POSSUM risk), logistic (male and type of operation), and ordinal (American Society of Anaesthesiologists physical status grade) regression models were used for other variables. Two-sided P values were obtained from specific statistical models, for which P < .05 was statistically significant. The 10 primary and secondary outcomes (the quality indicators) were assessed for evidence of improvement using Shewhart statistical process control charts. The statistical process control methodology is a branch of statistical tool that combines rigorous time series analysis with graphical presentation of data.27 This technique is particularly useful in the context of real-world large-scale change in which the control of independent variables is not always possible, in the way it is in more traditional experimental approaches.28 Statistical process control is increasingly being recognized as the optimal way of assessing QI projects in health care.29,30,31

ly useful in the context of real-world large-scale change in which the control of independent variables is not always possible, in the way it is in more traditional experimental approaches.28 Statistical process control is increasingly being recognized as the optimal way of assessing QI projects in health care.29,30,31 Monthly arithmetic means for each of the 10 quality indicators were plotted on time series charts. A baseline was constructed for the first 15 data points (from June 2014 through September 2015), and ongoing data were plotted on a monthly basis. For each of these charts, the expected mean value and upper and lower control limits were plotted (set at 3 SDs from the mean); these control limits are not CIs and cannot be interpreted in the same way. The charts were then inspected for common cause variation (random fluctuation) and special cause variation (changes due to external factors). Special cause variation or a substantial change not due to natural variation was identified, either when the mean monthly performance broached the upper or lower control limits or when 8 consecutive months of performance lay on 1 side of the mean line. The software used for the statistical analysis was SQCpack, version 7 (PQ Systems). Special cause variation was taken as a clinically and statistically significant change.

the mean monthly performance broached the upper or lower control limits or when 8 consecutive months of performance lay on 1 side of the mean line. The software used for the statistical analysis was SQCpack, version 7 (PQ Systems). Special cause variation was taken as a clinically and statistically significant change. Results A total of 28 hospitals participated in the ELC and completed the project. Aggregate-level patient demographics are shown in the Table. The baseline group included 5562 patients (2937 female [52.8%] and a mean [range] age of 65.3 [18-114] years), whereas the post-ELC group had 9247 patients (4911 female [53.1%] and a mean [range] age of 65 [18-99] years). No difference in age and sex was found. No significant difference was identified in median (interquartile range [IQR]) P-POSSUM (7.00% [2.7% to 21.9%] vs 6.30% [2.5% to 19.4%]; P = .002) and American Society of Anaesthesiologists physical status grades. No differences were identified in preoperative median (IQR) blood lactate level (1.4 [0-20] mmol/L vs 1.4 [1-20] mmol/L; P > .99) (to convert to milligrams per deciliter, multiply by 0.111) and other physiologic variables between the control and post-ELC groups. The most common surgical procedure type is contained in the eFigure in the Supplement.

d in preoperative median (IQR) blood lactate level (1.4 [0-20] mmol/L vs 1.4 [1-20] mmol/L; P > .99) (to convert to milligrams per deciliter, multiply by 0.111) and other physiologic variables between the control and post-ELC groups. The most common surgical procedure type is contained in the eFigure in the Supplement. Table. Comparison Between Baseline Group and Post–Emergency Laparotomy Collaborative Implementation Group Variable Baseline Group, mo 1-15 (n = 5562) Post-ELC Implementation Group, mo 16-39 (n = 9247) P Value Age, mean (range), y 65.3 (18-114) 65 (18-99) .33 Sex, No. (%) Male 2625 (47.2) 4336 (46.9) .72 Female 2937 (52.8) 4911 (53.1) No. of patients per mo, mean 371.6 386.9 .13 P-POSSUM, No. (%) Median (IQR) 7.00 (2.7-21.9) 6.30 (2.5-19.4) .002 0-10.0 3233 (58.1) 5661 (61.2) 10.1-20.0 834 (15.0) 1311 (14.2) 20.1-30.0 387 (7.0) 670 (7.2) 30.1-40.0 279 (5.0) 419 (4.5) 40.1-50.0 196 (3.5) 286 (3.1) 50.1-60.0 147 (2.6) 232 (2.5) 60.1-70.0 142 (2.6) 210 (2.3) 70.1-80.0 119 (2.1) 167 (1.8) 80.1-90.0 116 (2.1) 150 (1.6) 90.1-100 109 (2.0) 141 (1.5) ASA grade, No. (%) 1 554 (9.96) 1017 (11.00) .005 2 1988 (35.74) 3358 (36.31) 3 1976 (35.53) 3294 (35.62 4 936 (16.83) 1449 (15.67) 5 108 (1.94) 129 (1.40) Preoperative physiologic variables Blood lactate, median (range), mmol/L 1.4 (0-20) 1.4 (0.1-20) >.99 Systolic blood pressure, mean (range), mm Hg 126.9 (12-226) 127.1 (10.6-225) .63 Glasgow Coma Scale score,a mean (range) 14.7 (3-15) 14.7 (3-15) .47 Serum creatinine, mean (range), μmol/L 93.2 (0.8-1200) 91.1 (0.2-1083) .06 Abbreviations: ASA, American Society of Anaesthesiologists physical status; ELC, Emergency Laparotomy Collaborative; IQR, interquartile range; P-POSSUM, Portsmouth Physiological and Operative Severity Score for the enumeration of Mortality and morbidity. SI conversion factors: To convert lactate to milligrams per deciliter, multiply by 0.111; creatinine to milligrams per deciliter, multiply by 88.4.

mergency Laparotomy Collaborative; IQR, interquartile range; P-POSSUM, Portsmouth Physiological and Operative Severity Score for the enumeration of Mortality and morbidity. SI conversion factors: To convert lactate to milligrams per deciliter, multiply by 0.111; creatinine to milligrams per deciliter, multiply by 88.4. a Glasgow Coma Scale score range: 1-15, with the highest score indicating complete consciousness. During the ELC implementation period, a significant reduction was observed in both crude and P-POSSUM risk-adjusted mortality. Unadjusted mortality rate was 9.8% in the baseline period, fell to 9.0% in months 15 to 27, and declined again to 8.3% in months 28 to 39 (Figure 1). A significant change in mortality was observed after month 27. Figure 1. Change in Crude Mortality This statistical process control chart shows the stepwise reductions in 30-day unadjusted crude mortality. Months 1 to 15 depict the baseline data (ie, no intervention or care bundle from the Emergency Laparotomy Collaborative [ELC]); post-ELC months 16 to 27, year 1 change; and post-ELC months 28 to 39, year 2 change. LCL indicates lower control limit; UCL, upper control limit. The P-POSSUM risk-adjusted mortality also fell during the study period from 5.5% at baseline to 5.1% in months 15 to 27 and 4.5% in months 28 to 39. Again, a significant change was identified after month 27.

Figure 1. Change in Crude Mortality This statistical process control chart shows the stepwise reductions in 30-day unadjusted crude mortality. Months 1 to 15 depict the baseline data (ie, no intervention or care bundle from the Emergency Laparotomy Collaborative [ELC]); post-ELC months 16 to 27, year 1 change; and post-ELC months 28 to 39, year 2 change. LCL indicates lower control limit; UCL, upper control limit. The P-POSSUM risk-adjusted mortality also fell during the study period from 5.5% at baseline to 5.1% in months 15 to 27 and 4.5% in months 28 to 39. Again, a significant change was identified after month 27. The baseline LOS mean was 20.1 days, which decreased to 18.9 days during year 1 and remained at 18.9 days during year 2 of ELC implementation. A significant change in patient LOS occurred between months 26 to 36, but this change was not sustained beyond month 36 (Figure 2).

The P-POSSUM risk-adjusted mortality also fell during the study period from 5.5% at baseline to 5.1% in months 15 to 27 and 4.5% in months 28 to 39. Again, a significant change was identified after month 27. The baseline LOS mean was 20.1 days, which decreased to 18.9 days during year 1 and remained at 18.9 days during year 2 of ELC implementation. A significant change in patient LOS occurred between months 26 to 36, but this change was not sustained beyond month 36 (Figure 2). Figure 2. Change in Length of Stay (LOS) This statistical process control chart shows the change in baseline LOS. The mean baseline LOS was 20.1 days, which decreased to 18.9 days in post–ELC (Emergency Laparotomy Collaborative) months 13 to 27 and remained at 18.9 days for post-ELC months 28 to 39. The dark blue circles are monthly data readings; the filled orange circles are significant changes on 1 side of the mean line, indicating significance; and the empty orange circles are data points that lead up to significance. If more than 8 points lie on 1 side of the mean line, then the change is significant, which includes empty orange circles and filled orange circles. If the points cross the upper control limit (UCL) or the lower control limit (LCL), this is highly significant.

range circles are data points that lead up to significance. If more than 8 points lie on 1 side of the mean line, then the change is significant, which includes empty orange circles and filled orange circles. If the points cross the upper control limit (UCL) or the lower control limit (LCL), this is highly significant. A significant change in the P-POSSUM was identified during the study period. Overall, the preoperative P-POSSUM risk of death in the control group was 17.7%, which was reduced to 16.6% in months 16 to 27 and 15.5% in months 28 to 39 of the ELC implementation. The preoperative P-POSSUM showed a significant reduction from month 20 onward, and this decrease was sustained throughout the project. Aggregate-level data for all hospital metrics are shown in Figure 3 and Figure 4. In the baseline period, 63.9% of patients (3554 of 5562) had their blood lactate levels measured before arrival in the OR. This percentage increased to 71.2% (3381 patients) in months 16 to 27 and to 74.9% (3372 patients) in months 28 to 39. A significant improvement was identified that started before the beginning of the ELC implementation and was sustained and increased throughout the ELC project (Figure 3A).

ed before arrival in the OR. This percentage increased to 71.2% (3381 patients) in months 16 to 27 and to 74.9% (3372 patients) in months 28 to 39. A significant improvement was identified that started before the beginning of the ELC implementation and was sustained and increased throughout the ELC project (Figure 3A). Figure 3. Baseline to Post–Emergency Laparotomy Collaborative (ELC) Changes by Lactate Level, Antibiotics Use, Operating Room (OR) Access, and Goal-Directed Fluid Therapy (GDFT) Use A, Changes in the measurement of blood lactate level from baseline (63.9%) to post-ELC implementation year 1 (71.2%) and year 2 (74.9%), a significant change that crossed the upper control limit (UCL) of the statistical process chart. B, Changes in the use of antibiotics before OR arrival: 57.1% of patients received antibiotics during baseline, which decreased to 56.6% in year 1 and 52.3% in year 2. C, Changes in the percentage of patients who entered the OR within 6 hours of booking, which was 77.2% at baseline but increased to 79.4% in months 16 to 27 and to 80.8% in year 2. D, Changes in the use of GDFT, which was less than 42.3% preoperatively but increased beginning in month 25 onward, a significant change that was sustained and crossed the UCL. The dark blue circles are monthly data readings; the filled orange circles are significant changes on 1 side of the mean line, indicating significance; and the empty orange circles are data points that lead up to significance. If more than 8 points lie on 1 side of the mean line, then the change is significant, which includes empty orange circles and filled orange circles. If the points cross the UCL or the lower control limit (LCL), this is highly significant.

cance; and the empty orange circles are data points that lead up to significance. If more than 8 points lie on 1 side of the mean line, then the change is significant, which includes empty orange circles and filled orange circles. If the points cross the UCL or the lower control limit (LCL), this is highly significant. Figure 4. Baseline to Post–Emergency Laparotomy Collaborative (ELC) Changes by Intensive Care Unit (ICU) Admission and Surgeon and Anesthesiologist Involvement Changes in the admission rate to the ICU just before ELC implementation (month 14), which was a significant and sustained change that crossed the upper control limit (UCL) (A); the direct involvement of a senior surgeon, which occurred after month 18, crossed the UCL, and was significant (B); and the direct involvement of a senior anesthesiologist experienced by 74.8% of patients at baseline and increased to 85.8% in months 16 to 27 and was sustained in months 28 to 39 (C). See the caption to Figure 3 for explanation of dark blue circles, filled orange circles, and the empty orange circles. LCL indicates lower control limit. In the baseline period, 2875 (57.1%) of 5562 patients had antibiotics administered before arrival in the OR, and this number reduced to 2688 (56.6%) of 4748 patients in months 16 to 27 and to 2354 (52.3%) of 4499 patients in months 28 to 39. A significant deterioration was identified that started at month 30 and continued until the end of the project (Figure 3B).

patients had antibiotics administered before arrival in the OR, and this number reduced to 2688 (56.6%) of 4748 patients in months 16 to 27 and to 2354 (52.3%) of 4499 patients in months 28 to 39. A significant deterioration was identified that started at month 30 and continued until the end of the project (Figure 3B). The percentage of patients who entered the OR within 6 hours of booking was 77.2% in the baseline period. In months 16 to 27, this percentage increased to 79.4% and then to 80.8% in months 28 to 39. Overall, the improvement in access to the OR that started just before the start of the ELC project lasted from month 1 to month 3. This improvement was not sustained throughout the implementation, but it occurred again from months 34 to 39 (Figure 3C). The use of GDFT in the OR is shown in Figure 3D. Before the start of ELC, 42.3% of patients (2353 of 5562) were managed using GDFT. This percentage increased to 44.5% (2115 of 4748 patients) in months 16 to 27 and again to 56.3% (2534 of 4499 patients) in months 28 to 39. A significant change in the use of GDFT occurred from month 25 and was sustained. The admission rate to the intensive care unit before the ELC project was 62.9%. Again, a significant change in admission rate was seen starting just before the ELC implementation (month 14) and continued to improve throughout the project. The data show not only a significant but also a sustained change (Figure 4E).

The use of GDFT in the OR is shown in Figure 3D. Before the start of ELC, 42.3% of patients (2353 of 5562) were managed using GDFT. This percentage increased to 44.5% (2115 of 4748 patients) in months 16 to 27 and again to 56.3% (2534 of 4499 patients) in months 28 to 39. A significant change in the use of GDFT occurred from month 25 and was sustained. The admission rate to the intensive care unit before the ELC project was 62.9%. Again, a significant change in admission rate was seen starting just before the ELC implementation (month 14) and continued to improve throughout the project. The data show not only a significant but also a sustained change (Figure 4E). Direct involvement by a senior surgeon was experienced by 87.0% of patients (4839 of 5562) before the ELC implementation. During months 16 to 27, this involvement increased to 91.4% (4340 of 4748 patients) and to 94.2% (4238 of 4499 patients) during months 28 to 39. The improvements in compliance with this metric started before the project (month 11) but continued throughout the implementation. A significant change occurred after month 18 (Figure 4B). Before the ELC project, 74.8% of patients (4160 of 5562) experienced the direct involvement of a senior anesthesiologist. A significant change was seen, increasing involvement to 85.8% (4075 of 4748 patients) in months 16 to 27, which was sustained in months 28 to 39 (Figure 4C).

Direct involvement by a senior surgeon was experienced by 87.0% of patients (4839 of 5562) before the ELC implementation. During months 16 to 27, this involvement increased to 91.4% (4340 of 4748 patients) and to 94.2% (4238 of 4499 patients) during months 28 to 39. The improvements in compliance with this metric started before the project (month 11) but continued throughout the implementation. A significant change occurred after month 18 (Figure 4B). Before the ELC project, 74.8% of patients (4160 of 5562) experienced the direct involvement of a senior anesthesiologist. A significant change was seen, increasing involvement to 85.8% (4075 of 4748 patients) in months 16 to 27, which was sustained in months 28 to 39 (Figure 4C). Discussion This study showed a reduction in unadjusted mortality rate and LOS as well as changes in many of the care bundle metrics after ELC implementation, suggesting that improvements in the delivery of care can be achieved. Metrics were seen to change at different rates. More marked changes occurred in the second year of the project, supporting the concept that improvement work takes time to establish.32 Better attendance by senior clinicians occurred early, as did the measurement of blood lactate levels and admission to the intensive care unit. Improvement in accessing the OR was often not maintained, and sustained change occurred late in the project, suggesting that this target was more complex and may first require substantial upgrades to the system at many levels. Better use of GDFT was significant but did not occur until month 17.

the intensive care unit. Improvement in accessing the OR was often not maintained, and sustained change occurred late in the project, suggesting that this target was more complex and may first require substantial upgrades to the system at many levels. Better use of GDFT was significant but did not occur until month 17. The use of antibiotics declined during the project, especially during the later stages of ELC implementation. This finding is surprising in view of the concurrent focus in the United Kingdom to improve identification and early treatment of patients with sepsis. One explanation may be the observed change in case mix, with fewer other cases included in the database in the implementation period than in the baseline period. Another explanation could be that the NELA data set did not allow us to distinguish patients who showed signs of sepsis and required early antibiotics from patients who were not in septic shock. Considerably more other procedures were performed in the baseline group compared with the intervention (or post-ELC) group (eFigure in the Supplement). The use of the NELA database was relatively new at the start of the baseline period, and clinicians were likely not completely familiar with the specific codes used by the NELA database.

other procedures were performed in the baseline group compared with the intervention (or post-ELC) group (eFigure in the Supplement). The use of the NELA database was relatively new at the start of the baseline period, and clinicians were likely not completely familiar with the specific codes used by the NELA database. A reduction in the median P-POSSUM risk-adjusted mortality at 30 days was identified, and several possibilities may account for this decrease. Patient selection might have changed, but overall patient accrual rate and physiologic variables remained unchanged. Patients with high P-POSSUM risk-adjusted mortality at 30 days may have been denied for a surgical procedure, but again no evidence supports this possibility when looking at the P-POSSUM distribution. The care bundle itself may have advantages for the recorded P-POSSUM. The measurement of blood lactate level or the recording of the early warning score may have prompted earlier patient resuscitation, associated with improved physiologic variables and reduced overall P-POSSUM.

hen looking at the P-POSSUM distribution. The care bundle itself may have advantages for the recorded P-POSSUM. The measurement of blood lactate level or the recording of the early warning score may have prompted earlier patient resuscitation, associated with improved physiologic variables and reduced overall P-POSSUM. The ELC project had several features to encourage success. The care bundle approach offered a small number of simple, evidence-based metrics on which teams could focus their QI work, and collaboration among a number of hospitals has been shown to be more effective than hospitals working alone on improvement projects.33,34 The Michigan Surgical Quality Collaborative has demonstrated this very effectively.35 The use of frequent and timely data feedback has been shown to be a good indicator of successful QI initiatives.36 Highlighting and providing data to clinicians in an accessible manner to show their performance against peers, as was done using our dashboard, has also been shown to improve performance.37

effectively.35 The use of frequent and timely data feedback has been shown to be a good indicator of successful QI initiatives.36 Highlighting and providing data to clinicians in an accessible manner to show their performance against peers, as was done using our dashboard, has also been shown to improve performance.37 Strengths and Limitations The study has strengths, including its use of established improvement science methodology, the size of the collaborative group, and the large cohort of patients. This study also has several limitations. The NELA data set for data entry and baseline data was not designed specifically for the care bundle metrics. Another limitation is that the project took place against a backdrop of national interest in improving outcomes for emergency laparotomy. Distinguishing improvements owing to the ELC project from those associated with the prevailing trend is challenging. In addition, the availability of data for the treatment of sepsis was not ideal. Identifying those patients who should have received antibiotics when indicated would have been more useful. Conclusions The 28 participating hospitals in this collaborative project used a QI methodology and a care bundle and appeared to have substantial gains in both mortality rate and LOS. Significant improvements in recognized quality standards of care were achieved. Hospitals wishing for better outcomes for patients requiring emergency laparotomy should consider adopting a care bundle approach and participating in a QI collaborative group to see improvement in performance and reduction in mortality.

S. Significant improvements in recognized quality standards of care were achieved. Hospitals wishing for better outcomes for patients requiring emergency laparotomy should consider adopting a care bundle approach and participating in a QI collaborative group to see improvement in performance and reduction in mortality. Supplement. eFigure. Bar Chart Showing the Commonest Procedures Under the Umbrella Term “Emergency Laparotomy” Carried Out During Baseline and Intervention Click here for additional data file.

Introduction In many fields of general surgery (eg, hepatopancreatobiliary surgery), accurate knowledge and understanding of the patient’s anatomy with all details (eg, vasculature) is the key requirement in surgical decision making. The interpretation of complex anatomy based on conventional cross-sectional imaging is difficult and susceptible to errors because it requires advanced spatial reasoning abilities. Misinterpretation of imaging data corrupts preoperative decision making and the designated surgical approach, which, in turn, may jeopardize patient outcomes. Virtual 3-dimensional (3-D) reconstruction techniques have been developed to overcome this subjective limitation, ultimately facilitating comprehension of patient anatomy.1,2,3 However, conventional volume-rendering techniques provide images of limited quality that do not allow an adequate evaluation of complex intra-abdominal structures, such as the liver. In this regard, a more photorealistic visualization may facilitate image interpretation and improve the comprehension of the surgical anatomy.4,5

conventional volume-rendering techniques provide images of limited quality that do not allow an adequate evaluation of complex intra-abdominal structures, such as the liver. In this regard, a more photorealistic visualization may facilitate image interpretation and improve the comprehension of the surgical anatomy.4,5 In 2016, a new technique for 3-D visualization of cross-sectional image data called cinematic rendering (CR) was introduced.6,7,8 Cinematic rendering is a physically based volume-rendering method that works with random sampling computational algorithms. Different light maps and transfer functions are used to generate a realistic depiction of medical imaging data.8 This enhanced simulation of the paths of light rays enables CR to provide images with higher quality compared with conventional volume-rendering techniques.4,5,7,8,9,10,11,12,13 In our study, we assessed the value of CR in the comprehension of surgical anatomy. Using a customized workstation for postprocessing and real-time acquisition of CR images, we compared computed tomography (CT) with CR imaging using objective and subjective assessment questionnaires.

In 2016, a new technique for 3-D visualization of cross-sectional image data called cinematic rendering (CR) was introduced.6,7,8 Cinematic rendering is a physically based volume-rendering method that works with random sampling computational algorithms. Different light maps and transfer functions are used to generate a realistic depiction of medical imaging data.8 This enhanced simulation of the paths of light rays enables CR to provide images with higher quality compared with conventional volume-rendering techniques.4,5,7,8,9,10,11,12,13 In our study, we assessed the value of CR in the comprehension of surgical anatomy. Using a customized workstation for postprocessing and real-time acquisition of CR images, we compared computed tomography (CT) with CR imaging using objective and subjective assessment questionnaires. Methods Cinematic Rendering: Technical Background Cinematic rendering is a physically based volume-rendering technique. This crossover study used a Monte Carlo path-tracing method to compute the interaction of photons with the scanned patient data.6 This path-tracing method was first deployed in computer animation programs by the entertainment industry.7 This rendering method works with data retrieved from conventional CT or magnetic resonance scans. Hence, the image quality is determined by the original resolution and increases with the number of light paths that are traced. The use of high-dynamic-range–rendering light maps for illumination and the real-time computation of complex lighting effects produce a photorealistic depiction of the image data (Video 1).

s. Hence, the image quality is determined by the original resolution and increases with the number of light paths that are traced. The use of high-dynamic-range–rendering light maps for illumination and the real-time computation of complex lighting effects produce a photorealistic depiction of the image data (Video 1). Video 1. Cinematic Rendering Animation of Patient Case 14. The Cinematic Rendering for Surgery application used in this study was developed in a multistep innovation process in a collaboration between Siemens Healthineers and the Department of Surgery of the University Hospital of Erlangen. This prototype is still used only for research purposes and is not yet approved for clinical use. Digital Imaging and Communications in Medicine (DICOM) data can be uploaded directly into the application without conversion. The interface displays the patient’s name and sex, imaging modality, type of radiologic protocol (eg, CT for pancreatic imaging), slice thickness, and number of images with a small, multiplanar reformat preview in the axial plane on the side. The prototype version has multiple options to manipulate the image, and 2 different display presets can be chosen. The image can be sliced with 3 clipping planes. Because of the importance of vasculature in surgery, there is an option to virtually show the vessels in front of the sectional plane, and multiplanar reformat images can be overlaid. Lighting (Brightness), window-levelling (Range), and window center (Anatomy) can be selected. The images are rendered in real time, and the quality depends on the resolution of the original image.

s an option to virtually show the vessels in front of the sectional plane, and multiplanar reformat images can be overlaid. Lighting (Brightness), window-levelling (Range), and window center (Anatomy) can be selected. The images are rendered in real time, and the quality depends on the resolution of the original image. Participants and Patient Cases This study followed the Consolidated Standards of Reporting Trials (CONSORT) reporting guideline. The medical ethics review committee of the University Hospital of Erlangen (University of Erlangen-Nürnberg, Germany) approved the study protocol. Informed consent was deemed unnecessary because we used completely anonymized imaging data. We randomly asked general surgery residents and attending surgeons from our department, the Department of Surgery of the University Hospital of Erlangen, to participate in this study. Nine resident surgeons and 9 attending surgeons agreed to participate in this study. Resident surgeons who participated were in postgraduate year 2 to 6. None of the participants had previous experience with volume-rendering techniques. Using an electronic database, we identified patient cases who were treated or followed up for hepatopancreatobiliary tumors at the Department of Surgery in the University Hospital of Erlangen, Germany, from January 1, 2015, through January 1, 2017. Subsequently, we selected 40 patients who had undergone a high-resolution CT of the abdomen at any time during their course of treatment. Only anonymized DICOM data from CT images with a maximum slice thickness of 1 mm were used.

e University Hospital of Erlangen, Germany, from January 1, 2015, through January 1, 2017. Subsequently, we selected 40 patients who had undergone a high-resolution CT of the abdomen at any time during their course of treatment. Only anonymized DICOM data from CT images with a maximum slice thickness of 1 mm were used. For each patient case, 1 question addressing crucial issues of anatomic understanding, preoperative planning, and intraoperative strategies was formulated (eTable 1 in the Supplement). These questions had to be answered by using either CR visualization or conventional CT imaging. The correct answers were predefined in the study protocol. Using the preset function of the application, CR and CT imaging packages were automatically generated in a standardized fashion for each patient case. We then set up starting images depicting the area of interest in 2 different planes for each imaging modality to speed up the evaluation process (Figure 1). The prepared imaging packages were used by all participants. Figure 1. Example Starting Images and Questions From Patient Cases Cinematic rendering (CR) and computed tomography (CT) images. A and B, test case 1 (Does the pancreatic head tumor have contact to the superior mesenteric artery?); C and D, test case 14 (Is the tumor supplied by vessels from the left hepatic artery?); and E and F, test case 20 (Show and name the arterial supply of the left liver lobe).

g (CR) and computed tomography (CT) images. A and B, test case 1 (Does the pancreatic head tumor have contact to the superior mesenteric artery?); C and D, test case 14 (Is the tumor supplied by vessels from the left hepatic artery?); and E and F, test case 20 (Show and name the arterial supply of the left liver lobe). Study Design and Assessment This preclinical study with a randomized 2-sequence crossover design was conducted from February to November 1, 2018, at the Department of Surgery in the University Hospital of Erlangen, Germany (Figure 2). For each participant, the selected patient cases were randomized either to a CR-CT sequence or a CT-CR sequence. The number of cases within the 2 sequence groups were balanced in regard to the experience of the surgeon (resident vs attending). The participants conducted their evaluations at separate time points in the presence of 1 interviewer (C.K.). Figure 2. Study Design CR indicates cinematic rendering; CT, computed tomography. After an introduction to the CR for surgery application, all participants were allowed to acclimate themselves to handling the hardware and software components. In addition, 2 separate patient cases were used to simulate the flow of the study, which enabled each participant to familiarize himself or herself with the objective assessments and self-assessment questionnaires.

, all participants were allowed to acclimate themselves to handling the hardware and software components. In addition, 2 separate patient cases were used to simulate the flow of the study, which enabled each participant to familiarize himself or herself with the objective assessments and self-assessment questionnaires. After this orientation, all participants completed the first assessment of 40 prepared patient cases according to the assigned image modality. After a washout period of at least 2 weeks, all cases were crossed over to the alternate imaging modality for a second assessment. For an objective assessment, all surgeons had to answer the predefined questions (1 per patient case). The interviewer tracked and documented the outcome measures. There was no time restriction. The primary outcome was the correctness of the answers. The secondary outcome was the time needed to give the answer.

After this orientation, all participants completed the first assessment of 40 prepared patient cases according to the assigned image modality. After a washout period of at least 2 weeks, all cases were crossed over to the alternate imaging modality for a second assessment. For an objective assessment, all surgeons had to answer the predefined questions (1 per patient case). The interviewer tracked and documented the outcome measures. There was no time restriction. The primary outcome was the correctness of the answers. The secondary outcome was the time needed to give the answer. We applied a case assessment questionnaire to rate participants’ perception of the advantage of using CR compared with conventional CT images in each CR assessment. This questionnaire consisted of 4 categories: comprehension of general anatomy, comprehension of vascular anatomy, comprehension of parenchymal anatomy, and comprehension of spatial relationships (eTable 2 in the Supplement). Moreover, a general assessment questionnaire we designed was applied at the beginning of the first assessment period and at the end of the second assessment period. This 9-item questionnaire was set up to explore a possible benefit of CR in 4 categories: general decision making, interdisciplinary decision making, intraoperative guidance, and informed consent discussions (eTable 3 in the Supplement). Both questionnaires were based on a typical 5-point Likert scale ranging from 1 for strongly disagree to 5 for strongly agree.

ore a possible benefit of CR in 4 categories: general decision making, interdisciplinary decision making, intraoperative guidance, and informed consent discussions (eTable 3 in the Supplement). Both questionnaires were based on a typical 5-point Likert scale ranging from 1 for strongly disagree to 5 for strongly agree. Statistical Analysis Results are presented as mean (SD) or as frequency data. Time to answer and the percentage correct were computed as treatment effects, period effects, and carryover effects by the method reported by Hills and Armitage14 for 2-period crossover clinical trials. These data were analyzed using the independent t test to evaluate between-group differences of the 2 sequence groups. For the interperiod difference, the difference of assessment period 1 and assessment period 2 was computed. Differences between resident and attending physicians were analyzed with the Fisher exact test (questionnaire scores) or with the independent t test (time to answer and percentage of correctness). Statistical significance was determined as 2-sided P < .05. The analysis was conducted using SPSS, version 20 (SPSS Inc).

Statistical Analysis Results are presented as mean (SD) or as frequency data. Time to answer and the percentage correct were computed as treatment effects, period effects, and carryover effects by the method reported by Hills and Armitage14 for 2-period crossover clinical trials. These data were analyzed using the independent t test to evaluate between-group differences of the 2 sequence groups. For the interperiod difference, the difference of assessment period 1 and assessment period 2 was computed. Differences between resident and attending physicians were analyzed with the Fisher exact test (questionnaire scores) or with the independent t test (time to answer and percentage of correctness). Statistical significance was determined as 2-sided P < .05. The analysis was conducted using SPSS, version 20 (SPSS Inc). Results Objective Assessment Eighteen surgeons completed a total of 720 case evaluations. Cinematic rendering visualization was associated with a better anatomic understanding compared with conventional CT imaging. For the CR-CT sequence, the overall mean (SD) percentage of correct answers for CR assessment was 98.7% (2.2%); for CT assessment, 90.2% (7.0%); and for mean (SD) difference over time, 8.5% (7.0%). For the CT-CR sequence, the overall percentage of correct answers for CT assessment was 86.6% (6.6%); for CR assessment, 99.7% (1.4%); and for mean difference over time, –13.1% (6.3%); P < .001 by independent t test (Figure 3B). This association was also detectable in the subgroups of resident and attending surgeons (eTable 4 in the Supplement). The percentage of correct answers did not differ significantly between resident and attending surgeons for the CT assessment (86.9% [6.6%] vs 89.9% [7.2%]; P = .21) and for the CR assessment (99.2% [1.8%] vs 99.1% [2.0%]; P = .90).

ctable in the subgroups of resident and attending surgeons (eTable 4 in the Supplement). The percentage of correct answers did not differ significantly between resident and attending surgeons for the CT assessment (86.9% [6.6%] vs 89.9% [7.2%]; P = .21) and for the CR assessment (99.2% [1.8%] vs 99.1% [2.0%]; P = .90). Figure 3. Association of Cinematic Rendering (CR) With Correctness of Answers and Time to Answer A, Rate of correct answers. B, Time needed to answer according to the sequence. CT indicates computed tomography.

ctable in the subgroups of resident and attending surgeons (eTable 4 in the Supplement). The percentage of correct answers did not differ significantly between resident and attending surgeons for the CT assessment (86.9% [6.6%] vs 89.9% [7.2%]; P = .21) and for the CR assessment (99.2% [1.8%] vs 99.1% [2.0%]; P = .90). Figure 3. Association of Cinematic Rendering (CR) With Correctness of Answers and Time to Answer A, Rate of correct answers. B, Time needed to answer according to the sequence. CT indicates computed tomography. Mean time spent by all participants with the CR assessment was significantly shorter than with the CT assessment. For the CR-CT sequence, the mean (SD) time for the CR assessment was 56.6 (54.6) seconds; for CT assessment, 75.0 (69.1) seconds; and for mean (SD) difference over time, –18.3 (76.9) seconds. For the CT-CR sequence, the mean (SD) time for the CT assessment was 95.1 (83.7) seconds; for CR assessment, 42.7 (48.9) seconds; and for mean (SD) difference over time, 52.4 (88.5) seconds; P < .001 by independent t test (Figure 3A). This association was still evident after stratification according to surgeon experience (resident vs attending) (eTable 4 in the Supplement). Moreover, resident surgeons needed significantly more time for their answers compared with attending surgeons, no matter which visualization modality they used (CT: residents, 103.3 [87.2] seconds vs attending surgeons, 66.8 [60.8] seconds; P < .001 and CR: residents, 55.7 [54.3] seconds vs attending surgeons, 43.6 [49.6] seconds; P = .002). However, time reduction by CR was 48% for resident surgeons and 32.5% for attending surgeons (P = .01). No carryover or period effects were observed.

s, 103.3 [87.2] seconds vs attending surgeons, 66.8 [60.8] seconds; P < .001 and CR: residents, 55.7 [54.3] seconds vs attending surgeons, 43.6 [49.6] seconds; P = .002). However, time reduction by CR was 48% for resident surgeons and 32.5% for attending surgeons (P = .01). No carryover or period effects were observed. Case Assessment Questionnaire The ratings of the case assessment according to the different categories and surgeon experience are summarized as a Likert plot in Figure 4. In total, the self-assessment questionnaire revealed that, in most cases, participants agreed that CR is beneficial for the comprehension of the surgical anatomy (overall mean (SD) score, 4.53 [0.75]). Independent of surgeon experience, the question categories of vascular anatomy and spatial relationship received the highest scores (vascular anatomy, 4.63 [0.68]; spatial relationship, 4.58 [0.73]). The mean (SD) score for general anatomy was 4.52 (0.72) and for parenchymal anatomy, 4.39 (0.84). In all categories, the ratings of resident surgeons were significantly higher than those of the attending surgeons (eTable 5 in the Supplement). Figure 4. Responses to the Case Assessment Questionnaire Mean scores are depicted within the gray circles.

Case Assessment Questionnaire The ratings of the case assessment according to the different categories and surgeon experience are summarized as a Likert plot in Figure 4. In total, the self-assessment questionnaire revealed that, in most cases, participants agreed that CR is beneficial for the comprehension of the surgical anatomy (overall mean (SD) score, 4.53 [0.75]). Independent of surgeon experience, the question categories of vascular anatomy and spatial relationship received the highest scores (vascular anatomy, 4.63 [0.68]; spatial relationship, 4.58 [0.73]). The mean (SD) score for general anatomy was 4.52 (0.72) and for parenchymal anatomy, 4.39 (0.84). In all categories, the ratings of resident surgeons were significantly higher than those of the attending surgeons (eTable 5 in the Supplement). Figure 4. Responses to the Case Assessment Questionnaire Mean scores are depicted within the gray circles. General Assessment Questionnaire The responses to the general assessment questionnaire according to different categories and surgeon experience are summarized as a Likert plot in the eFigure in the Supplement. The highest scores were given for the statement “CR may help with explanations during informed consent discussions.” As in the case assessment questionnaire, ratings of resident surgeons tended to be higher than those of the attending surgeons. Only the scores for question 9 (“CR can help with explanations during informed consent discussions”) differed significantly between resident and attending surgeons (mean [SD] score; resident surgeons, 5.0 [0]; attending surgeons 4.3 (0.9); P = .04).

ent surgeons tended to be higher than those of the attending surgeons. Only the scores for question 9 (“CR can help with explanations during informed consent discussions”) differed significantly between resident and attending surgeons (mean [SD] score; resident surgeons, 5.0 [0]; attending surgeons 4.3 (0.9); P = .04). Resident surgeons rated CR as beneficial in relation to all 9 questions (mean [SD] score for each question, >3). Attending surgeons were undetermined toward a beneficial influence of CR on interdisciplinary decision making for multimodal therapy concepts (mean [SD] score for question 8: 2.9 [1.6]) and in regard to a reduction of time needed for therapeutic decisions (question 4: 3.0 [1.5]). The responses to the general assessment questionnaire did not differ significantly over time (eg, mean [SD] score for question 1: first assessment, 3.3 [1.3]; second assessment, 3.5 [1.3]; P = .30).

for question 8: 2.9 [1.6]) and in regard to a reduction of time needed for therapeutic decisions (question 4: 3.0 [1.5]). The responses to the general assessment questionnaire did not differ significantly over time (eg, mean [SD] score for question 1: first assessment, 3.3 [1.3]; second assessment, 3.5 [1.3]; P = .30). Discussion Our investigation showed that CR imaging reduces the time needed to answer anatomy-related questions. Most of all, the correctness of answers increased when CR was used. In regard to the complexity of our questions, these results demonstrate that CR helps to transfer complex anatomical information to clinicians. Recently, Marconi et al15 reported that 3-D–printed models allowed the best anatomical understanding, with faster and clearer comprehension of the surgical anatomy. This study was set up to validate the preoperative use of 3-D–printed anatomical models in comparison with conventional CT imaging and volume-rendering visualizations. Both 3-D–printed anatomical models and conventional volume-rendering visualizations significantly increased the correctness of answers and the time spent for evaluations compared with conventional CT imaging. However, there were no significant differences between conventional volume-rendering visualizations and 3-D–printed models. The authors stated that the possibility of grasping a physical object is the most evident advantage of 3-D–printed models, allowing a mental reconstruction and memorization of the anatomy. Because there is a substantial improvement of depth perception in CR reconstructions, we think that CR, in contrast to conventional volume rendering, offers similar advantages. At the same time, CR visualization can be easily and quickly provided via the Cinematic Rendering for Surgery application through real-time postprocessing using a computer or tablet. In addition, there is no need for a 3-D printer or radiologic validation of the virtual model that is retrieved from a series of medical images after image segmentation.

on can be easily and quickly provided via the Cinematic Rendering for Surgery application through real-time postprocessing using a computer or tablet. In addition, there is no need for a 3-D printer or radiologic validation of the virtual model that is retrieved from a series of medical images after image segmentation. That CR visualization improves the correctness of image interpretation is an obviously important finding of this study. However, from our point of view, the time savings conferred by the use of CR are equally important, because time is a rare commodity in the daily routine of surgeons. Tools that speed up image interpretation will help to save time in a variety of situations (eg, preoperative planning, intraoperative decision making). In addition, multiparty decision making may benefit, if all participants have access to a faster assessment of volume imaging. In the present study, we also aimed to evaluate the benefits of CR imaging in regard to the level of expertise. As expected, the time to answer was significantly greater in the resident surgeon group than in the attending surgeon group, regardless of the imaging technique. Of note, the time reduction through CR imaging was significantly greater for resident (48%) than attending surgeons (32.5%). These results show that resident surgeons benefit more than attending surgeons when using CR imaging, although the increase of correct answers did not significantly differ between resident and attending surgeons.

reduction through CR imaging was significantly greater for resident (48%) than attending surgeons (32.5%). These results show that resident surgeons benefit more than attending surgeons when using CR imaging, although the increase of correct answers did not significantly differ between resident and attending surgeons. We applied a case assessment questionnaire to rate the participants’ perception of the advantage of using CR in regard to the understanding of the patient anatomy. Independent of their level of experience, surgeons perceived CR as beneficial for the comprehension of vascular anatomy and spatial relationship (highest mean scores). This finding is in line with previous results reporting particularly impressive visualizations of high-density and high-contrast structures such as bones or contrast-enhanced vessels by CR.2 In addition, these results reflect the substantial contribution of CR visualization to depth perception by complex lighting effects.

s finding is in line with previous results reporting particularly impressive visualizations of high-density and high-contrast structures such as bones or contrast-enhanced vessels by CR.2 In addition, these results reflect the substantial contribution of CR visualization to depth perception by complex lighting effects. Cinematic rendering is a technique for 3-D visualization that confirms decisions through real-time acquisition of photorealistic and lifelike images from medical data. These features may allow a deployment of 3-D visualizations in new fields of application. To explore the participants’ opinions on potential future applications of CR, we included a general assessment questionnaire in our study. There was an overall agreement that CR may be helpful in regard to general and interdisciplinary decision making, intraoperative guidance, and informed consent discussions. Resident surgeons tended to have a more positive outlook on future applications of CR. In this context, we think that CR is a perfect tool to enhance anatomy education of surgical residents and medical students.10,16 Photorealistic images are suitable to recall and deepen knowledge of anatomy. Cinematic rendering also provides the possibility of virtual immersion in patient cases involving different variants of anatomical structures or manifestations of diseases.

ce anatomy education of surgical residents and medical students.10,16 Photorealistic images are suitable to recall and deepen knowledge of anatomy. Cinematic rendering also provides the possibility of virtual immersion in patient cases involving different variants of anatomical structures or manifestations of diseases. Limitations This study has several limitations worthy of consideration. First, adaptation to the CR software may have added to response time, because CR was unfamiliar and possibly appeared more complex than conventional imaging in the first place. Although all surgeons were obliged to test the CR software with 2 additional cases before being admitted to this study, we cannot exclude the possibility that there has been a learning curve in handling the CR software during the first CR cases of this study. Second, the emphasis of this study was a general evaluation of CR imaging and not to examine differences in visualization among different tissue types. Although we conducted a subjective case assessment, we cannot draw conclusions on objective benefits of CR in regard to certain types of tissues. Third, because this is a nonclinical study, we can only speculate about the potential influence that CR imaging may have on surgeons owing to an improved comprehension of the patient anatomy. Thus, it remains to be determined whether the routine clinical use of CR may improve surgical decision making, ultimately leading to a reduction of intraoperative mistakes and an improvement in patient outcomes.1 In this regard, further research should focus on intraoperative guidance, including an integration of CR imaging into augmented reality technologies (eg, Microsoft HoloLens).

of CR may improve surgical decision making, ultimately leading to a reduction of intraoperative mistakes and an improvement in patient outcomes.1 In this regard, further research should focus on intraoperative guidance, including an integration of CR imaging into augmented reality technologies (eg, Microsoft HoloLens). Conclusions This study shows that CR imaging speeds up and improves the understanding of complex anatomical situations compared with CT. Surgeons perceive CR imaging as a helpful tool that not only promotes their anatomical understanding but may also enhance preoperative and intraoperative decision making. Additional studies are needed to further explore the benefits of CR imaging in the clinical setting. Supplement. eFigure. Likert Plot of the Responses to the General Assessment Questionnaire eTable 1. Patient Case Questions eTable 2. Case Assessment Questionnaire eTable 3. General Assessment Questionnaire eTable 4. Results of Objective Assessment According to the Type of Surgeon eTable 5. Ratings of the Case Assessment Questionnaire According to Different Categories and Type of Surgeon Click here for additional data file.