The effect of prehospital transport time, injury severity, and blood transfusion on survival of US military casualties in Iraq.

BACKGROUND: Reducing time from injury to care can optimize trauma patient outcomes. A previous study of prehospital transport of US military casualties during the Afghanistan conflict demonstrated the importance of time and treatment capability for combat casualty survival. METHODS: A retrospective descriptive analysis was conducted to analyze battlefield data collected on US military combat casualties during the Iraq conflict from March 19, 2003, to August 31, 2010. All casualties were analyzed by mortality outcome (killed in action, died of wounds, case fatality rate) and compared with Afghanistan conflict. Detailed data for those who underwent prehospital transport were analyzed for effects of transport time, injury severity, and blood transfusion on survival. RESULTS: For the total population, percent killed in action (16.6% vs. 11.1%), percent died of wounds (5.9% vs. 4.3%), and case fatality rate (10.0 vs. 8.6) were higher for Iraq versus Afghanistan (p < 0.001). Among 1,692 casualties (mean New Injury Severity Score, 22.5; mortality, 17.6%) with detailed data, the injury mechanism included 77.7% from explosions and 22.1% from gunshot wounds. For prehospital transport, 67.6% of casualties were transported within 60 minutes, and 32.4% of casualties were transported in greater than 60 minutes. Although 97.0% of deaths occurred in critical casualties (New Injury Severity Score, 25-75), 52.7% of critical casualties survived. Critical casualties were transported more rapidly (p < 0.01) and more frequently within 60 minutes (p < 0.01) than other casualties. Critical casualties had lower mortality when blood was received (p < 0.01). Among critical casualties, blood transfusion was associated with survival irrespective of transport time within or greater than 60 minutes (p < 0.01). CONCLUSION: Although data were limited, early blood transfusion was associated with battlefield survival in Iraq as it was in Afghanistan. LEVEL OF EVIDENCE: Performance improvement and epidemiological, level IV.

The Effect of a Golden Hour Policy on the Morbidity and Mortality of Combat Casualties.

IMPORTANCE: The term golden hour was coined to encourage urgency of trauma care. In 2009, Secretary of Defense Robert M. Gates mandated prehospital helicopter transport of critically injured combat casualties in 60 minutes or less. OBJECTIVES: To compare morbidity and mortality outcomes for casualties before vs after the mandate and for those who underwent prehospital helicopter transport in 60 minutes or less vs more than 60 minutes. DESIGN, SETTING, AND PARTICIPANTS: A retrospective descriptive analysis of battlefield data examined 21,089 US military casualties that occurred during the Afghanistan conflict from September 11, 2001, to March 31, 2014. Analysis was conducted from September 1, 2014, to January 21, 2015. MAIN OUTCOMES AND MEASURES: Data for all casualties were analyzed according to whether they occurred before or after the mandate. Detailed data for those who underwent prehospital helicopter transport were analyzed according to whether they occurred before or after the mandate and whether they occurred in 60 minutes or less vs more than 60 minutes. Casualties with minor wounds were excluded. Mortality and morbidity outcomes and treatment capability-related variables were compared. RESULTS: For the total casualty population, the percentage killed in action (16.0% [386 of 2411] vs 9.9% [964 of 9755]; P < .001) and the case fatality rate ([CFR] 13.7 [469 of 3429] vs 7.6 [1344 of 17,660]; P < .001) were higher before vs after the mandate, while the percentage died of wounds (4.1% [83 of 2025] vs 4.3% [380 of 8791]; P = .71) remained unchanged. Decline in CFR after the mandate was associated with an increasing percentage of casualties transported in 60 minutes or less (regression coefficient, -0.141; P < .001), with projected vs actual CFR equating to 359 lives saved. Among 4542 casualties (mean injury severity score, 17.3; mortality, 10.1% [457 of 4542]) with detailed data, there was a decrease in median transport time after the mandate (90 min vs 43 min; P < .001) and an increase in missions achieving prehospital helicopter transport in 60 minutes or less (24.8% [181 of 731] vs 75.2% [2867 of 3811]; P < .001). When adjusted for injury severity score and time period, the percentage killed in action was lower for those critically injured who received a blood transfusion (6.8% [40 of 589] vs 51.0% [249 of 488]; P < .001) and were transported in 60 minutes or less (25.7% [205 of 799] vs 30.2% [84 of 278]; P < .01), while the percentage died of wounds was lower among those critically injured initially treated by combat support hospitals (9.1% [48 of 530] vs 15.7% [86 of 547]; P < .01). Acute morbidity was higher among those critically injured who were transported in 60 minutes or less (36.9% [295 of 799] vs 27.3% [76 of 278]; P < .01), those severely and critically injured initially treated at combat support hospitals (severely injured, 51.1% [161 of 315] vs 33.1% [104 of 314]; P < .001; and critically injured, 39.8% [211 of 530] vs 29.3% [160 of 547]; P < .001), and casualties who received a blood transfusion (50.2% [618 of 1231] vs 3.7% [121 of 3311]; P < .001), emphasizing the need for timely advanced treatment. CONCLUSIONS AND RELEVANCE: A mandate made in 2009 by Secretary of Defense Gates reduced the time between combat injury and receiving definitive care. Prehospital transport time and treatment capability are important factors for casualty survival on the battlefield.