Use of Combat Casualty Care Data to Assess the US Military Trauma System During the Afghanistan and Iraq Conflicts, 2001-2017

Abstract

IMPORTANCE Although the Afghanistan and Iraq conflicts have the lowest US case-fatality rates in history, no comprehensive assessment of combat casualty care statistics, major interventions, or risk factors has been reported to date after 16 years of conflict. OBJECTIVES To analyze trends in overall combat casualty statistics, to assess aggregate measures of injury and interventions, and to simulate how mortality rates would have changed had the interventions not occurred. DESIGN, SETTING, AND PARTICIPANTS Retrospective analysis of all available aggregate and weighted individual administrative data compiled from Department of Defense databases on all 56 763 US military casualties injured in battle in Afghanistan and Iraq from October 1, 2001, through December 31, 2017. Casualty outcomes were compared with period-specific ratios of the use of tourniquets, blood transfusions, and transport to a surgical facility within 60 minutes. MAIN OUTCOMES AND MEASURES Main outcomes were casualty status (alive, killed in action [KIA], or died of wounds [DOW]) and the case-fatality rate (CFR). Regression, simulation, and decomposition analyses were used to assess associations between covariates, interventions, and individual casualty status; estimate casualty transitions (KIA to DOW, KIA to alive, and DOW to alive); and estimate the contribution of interventions to changes in CFR. RESULTS In aggregate data for 56 763 casualties, CFR decreased in Afghanistan (20.0% to 8.6%) and Iraq (20.4% to 10.1%) from early stages to later stages of the conflicts. Survival for critically injured casualties (Injury Severity Score, 25-75 [critical]) increased from 2.2% to 39.9% in Afghanistan and from 8.9% to 32.9% in Iraq. Simulations using data from 23 699 individual casualties showed that without interventions assessed, CFR would likely have been higher in Afghanistan (15.6% estimated vs 8.6% observed) and Iraq (16.3% estimated vs 10.1% observed), equating to 3672 additional deaths (95% CI, 3209-4244 deaths), of which 1623 (44.2%) were associated with the interventions studied: 474 deaths (12.9%) (95% CI, 439-510) associated with the use of tourniquets, 873 (23.8%) (95% CI, 840-910) with blood transfusion, and 275 (7.5%) (95% CI, 259-292) with prehospital transport times.CONCLUSIONS AND RELEVANCE Our analysis suggests that increased use of tourniquets, blood transfusions, and more rapid prehospital transport were associated with 44.2% of total mortality reduction. More critically injured casualties reached surgical care, with increased survival, implying improvements in prehospital and hospital care.

It is time to reconsider the risks of transfusing RhD negative females of childbearing potential with RhD positive red blood cells in bleeding emergencies

“…Furthermore, a secondary analysis of the Pragmatic Randomized Optimal Platelet and Plasma Ratios (PROPPR) trial that compared outcomes of trauma patients who were resuscitated with two different blood product ratios found a 5% increase in mortality for every minute that blood products were not provided to a trauma patient after the massive transfusion protocol (MTP) had been activated . Lastly, two recent studies of military casualties revealed that the prompt transfusion of blood products resulted in impressive reductions in mortality . These findings underscore the importance of having blood products available early in the resuscitation of massively bleeding trauma patients.…”

Applying trauma systems concepts to humanitarian battlefield care: a qualitative analysis of the Mosul trauma pathway

“…Moreover, the recent achievements of military trauma systems in reducing battlefield mortality have drawn upon many technological advances, including the use of blood products in far forward positions, the reliance on airpower for rapid evacuation of casualties, and the development of sophisticated trauma registries that have allowed for the identification of suboptimal care and real-time improvements. A recent analysis by Howell et al (2019), reviewing U.S. servicemember casualties in Iraq and Afghanistan, found that improvements in blood product availability, tourniquet use, and reduction in pre-hospital transport times accounted for nearly half of the reduction in case fatality in those conflicts [5]. Some observers have raised concerns that, in the absence of such advances, echeloning care may be counterproductive or even harmful if such echelons delay rather than expedite access to appropriate care.…”

“…In many ways, this pathway represented a marked departure from "business as usual" for humanitarian trauma care in wartime. Although echelons of care are well-described in war surgery literature, they are most commonly associated with western militaries, having been deployed in military responses in Vietnam, Israel, and the Falkland Islands in the 1970s and 1980s through Afghanistan and Iraq more recently [4,5]. These military evacuation chains provided first aid near the point of injury, transport of the critically wounded, and surgical care for combatants and, to varying degrees, injured civilians.…”

“…In the 2000s, the U.S.-led international coalition in Iraq and Afghanistan made massive investments in battlefield trauma systems that have been credited with a marked reduction in servicemember fatality rates compared to previous armed conflicts [17,18]. Critically, these systems feature not only multiple echelons of care (from point of injury to complex rehabilitative care), but also integrative components such as communication, transportation, data collection, and clinical practice guidelines that enabled a continuum of timely, quality care for the gravely injured [3,5]. Many of these elements have been credited with saving lives, including reduced times between injury and definitive care (often through the use of air evacuation to limit the time between injury and definitive care to less than one hour); better tactical prehospital care that prioritized hemorrhage control including tourniquet use, resuscitation with blood products, and hypothermia management; sustained en-route care during transportation; and real-time use of data to improve care delivery [5,19,20].…”

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“…11 This contemporary JTTS resulted in a steady decrease in combat case fatality rates despite increasingly severe injuries sustained by wounded troops. [12][13][14] The most recent analysis of data documents that between 2001 and 2017, the combat case fatality rates (defined as the number of troops killed in action plus those who died of wounds divided by the sum of those killed in action plus those wounded in action) decreased in Afghanistan from 20% to 8.6%; in Iraq it went from 20.4% to 10% 15 (Fig. 2).…”