Advancing Combat Casualty Care Statistics and Other Battlefield Care Metrics.

Aggregate statistics can provide intra-conflict and inter-conflict mortality comparisons and trends within and between U.S. combat operations. However, capturing individual-level data to evaluate medical and non-medical factors that influence combat casualty mortality has historically proven difficult. The Department of Defense (DoD) Trauma Registry, developed as an integral component of the Joint Trauma System during recent conflicts in Afghanistan and Iraq, has amassed individual-level data that have afforded greater opportunity for a variety of analyses and comparisons. Although aggregate statistics are easily calculated and commonly used across the DoD, other issues that require consideration include the impact of individual medical interventions, non-medical factors, non-battle-injured casualties, and incomplete or missing medical data, especially for prehospital care and forward surgical team care. Needed are novel methods to address these issues in order to provide a clearer interpretation of aggregate statistics and to highlight solutions that will ultimately increase survival and eliminate preventable death on the battlefield. Although many U.S. military combat fatalities sustain injuries deemed non-survivable, survival among these casualties might be improved using primary and secondary prevention strategies that prevent injury or reduce injury severity. The current commentary proposes adjustments to traditional aggregate combat casualty care statistics by integrating statistics from the DoD Military Trauma Mortality Review process as conducted by the Joint Trauma System and Armed Forces Medical Examiner System.

The Golden Hour of Casualty Care: Rapid Handoff to Surgical Team is Associated With Improved Survival in War-injured US Service Members.

OBJECTIVE: To examine time from injury to initiation of surgical care and association with survival in US military casualties. BACKGROUND: Although the advantage of trauma care within the "golden hour" after an injury is generally accepted, evidence is scarce. METHODS: This retrospective, population-based cohort study included US military casualties injured in Afghanistan and Iraq, January 2007 to December 2015, alive at initial request for evacuation with maximum abbreviated injury scale scores ≥2 and documented 30-day survival status after injury. Interventions: (1) handoff alive to the surgical team, and (2) initiation of first surgery were analyzed as time-dependent covariates (elapsed time from injury) using sequential Cox proportional hazards regression to assess how intervention timing might affect mortality. Covariates included age, injury year, and injury severity. RESULTS: Among 5269 patients (median age, 24 years; 97% males; and 68% battle-injured), 728 died within 30 days of injury, 68% within 1 hour, and 90% within 4 hours. Only handoffs within 1 hour of injury and the resultant timely initiation of emergency surgery (adjusted also for prior advanced resuscitative interventions) were significantly associated with reduced 24-hour mortality compared with more delayed surgical care (adjusted hazard ratios: 0.34; 95% CI: 0.14-0.82; P = 0.02; and 0.40; 95% CI: 0.20-0.81; P = 0.01, respectively). In-hospital waits for surgery (mean: 1.1 hours; 95% CI; 1.0-1.2) scarcely contributed ( P = 0.67). CONCLUSIONS: Rapid handoff to the surgical team within 1 hour of injury may reduce mortality by 66% in US military casualties. In the subgroup of casualties with indications for emergency surgery, rapid handoff with timely surgical intervention may reduce mortality by 60%. To inform future research and trauma system planning, findings are pivotal.

Operational Considerations for Crew Fatality on the International Space Station.

BACKGROUND: While catastrophic spaceflight events resulting in crew loss have occurred, human spaceflight has never suffered an on-orbit fatality with survival of other crewmembers on board. Historical plans for management of an on-orbit fatality have included some consideration for forensic documentation and sample collection, human remains containment, and disposition of remains; however, such plans have not included granular detailing of crew or ground controller actions. The NASA Johnson Space Center Contingency Medical Operations Group, under authority from the Space and Occupational Medicine Branch, the Space Medicine Operations Division, and the Human Health and Performance Directorate, undertook the development of a comprehensive plan, including an integrated Mission Control Center response for flight control teams and Flight Surgeons for a single on-orbit crew fatality on the International Space Station (ISS) and subsequent events. Here we detail the operational considerations for a crew fatality should it occur during spaceflight onboard the ISS, including forensic and timeline constraints, behavioral health factors, and considerations for final disposition of decedent remains. Future considerations for differential survival and crewmember fatality outside of low-Earth orbit operations will additionally be discussed, including consideration of factors unique to planetary and surface operations and disposition limitations in exploration spaceflight. While the efforts detailed herein were developed within the constraints of the ISS concept of operations, future platforms may benefit from the procedural validation and product verifications steps described. Ultimately, any response to spaceflight fatality must preserve the goal of handling decedent remains and disposition with dignity, honor, and respect.Stepaniak PC, Blue RS, Gilmore S, Beven GE, Chough NG, Tsung A, McMonigal KA, Mazuchowski EL II, Bytheway JA, Lindgren KN, Barratt MR. Operational considerations for crew fatality on the International Space Station. Aerosp Med Hum Perform. 2023; 94(9):705-714.

Remains Containment Considerations for Death in Low-Earth Orbit.

BACKGROUND: Maintenance and disposition of decedent remains during spaceflight require the isolation of biohazardous products of decomposition in microgravity and in the absence of refrigeration. Containment and isolation options would preferably offer sufficient time to enable crew and ground support teams to determine appropriate disposition of remains and even potentially return remains to the Earth. The pilot study described herein undertook an effort to develop a postmortem containment unit for the isolation and maintenance of decedent remains in a microgravity environment.METHODS: Commercial off-the-shelf containment units were modified to meet the needs of a microgravity spaceflight environment and to offer the best likelihood of successful containment and management of remains. A subsequent evaluation of modified containment unit performance was undertaken utilizing human cadavers, with measurement and analysis of volatile off-gassing over time followed by impact testing of the units containing cadaverous remains in a simulated spaceflight vehicle seat.RESULTS: Modifications were implemented without significant negative design impact. Failure was observed in one modified unit after 9 d and attributed to improper filter application. The remaining unit successfully contained remains beyond the intended endpoint of the study.DISCUSSION: These pilot efforts offer important insight into the development of effective postmortem containment options for future spaceflight. Further study is needed to ensure repeatability of the findings and to further characterize the failure modes of the modified units evaluated, the impact of microgravity conditions, and the identification of additional modifications that would improve remains disposition.Houser T, Lindgren KN, Mazuchowski EL II, Barratt MR, Haines DC, Jayakody M, Blue RS, Bytheway JA, Stepaniak PC. Remains containment considerations for death in low-Earth orbit. Aerosp Med Hum Perform. 2023; 94(5):368-376.

United States Military Fatalities During Operation Inherent Resolve and Operation Freedom's Sentinel.

BACKGROUND: Military operations provide a unified action and strategic approach to achieve national goals and objectives. Mortality reviews from military operations can guide injury prevention and casualty care efforts. METHODS: A retrospective study was conducted on all U.S. military fatalities from Operation Inherent Resolve (OIR) in Iraq (2014-2021) and Operation Freedom's Sentinel (OFS) in Afghanistan (2015-2021). Data were obtained from autopsy reports and other existing records. Fatalities were evaluated for population characteristics; manner, cause, and location of death; and underlying atherosclerosis. Non-suicide trauma fatalities were also evaluated for injury severity, mechanism of death, injury survivability, death preventability, and opportunities for improvement. RESULTS: Of 213 U.S. military fatalities (median age, 29 years; male, 93.0%; prehospital, 89.2%), 49.8% were from OIR, and 50.2% were from OFS. More OIR fatalities were Reserve and National Guard forces (OIR 22.6%; OFS 5.6%), conventional forces (OIR 82.1%; OFS 65.4%), and support personnel (OIR 61.3%; OFS 33.6%). More OIR fatalities also resulted from disease and non-battle injury (OIR 83.0%; OFS 28.0%). The leading cause of death was injury (OIR 81.1%; OFS 98.1%). Manner of death differed as more homicides (OIR 18.9%; OFS 72.9%) were seen in OFS, and more deaths from natural causes (OIR 18.9%; OFS 1.9%) and suicides (OIR 29.2%; OFS 6.5%) were seen in OIR. The prevalence of underlying atherosclerosis was 14.2% in OIR and 18.7% in OFS. Of 146 non-suicide trauma fatalities, most multiple/blunt force injury deaths (62.2%) occurred in OIR, and most blast injury deaths (77.8%) and gunshot wound deaths (76.6%) occurred in OFS. The leading mechanism of death was catastrophic tissue destruction (80.8%). Most fatalities had non-survivable injuries (80.8%) and non-preventable deaths (97.3%). CONCLUSIONS: Comprehensive mortality reviews should routinely be conducted for all military operation deaths. Understanding death from both injury and disease can guide preemptive and responsive efforts to reduce death among military forces.

United States military fatalities during Operation New Dawn.

BACKGROUND: Military operations vary by scope, purpose, and intensity, each having unique forces and actions to execute a mission. Evaluation of military operation fatalities guides current and future casualty care. METHODS: A retrospective study was conducted of all US military fatalities from Operation New Dawn in Iraq, 2010 to 2011. Data were obtained from autopsies and other records. Population characteristics, manner of death, cause of death, and location of death were analyzed. All fatalities were evaluated for concomitant evidence of underlying atherosclerosis. Nonsuicide trauma fatalities were also reviewed for injury severity, mechanism of death, injury survivability, death preventability, and opportunities for improvement. RESULTS: Of 74 US military Operation New Dawn fatalities (median age, 26 years; male, 98.6%; conventional forces, 100%; prehospital, 82.4%) the leading cause of death was injury (86.5%). The manner of death was primarily homicide (55.4%), followed by suicide (17.6%), natural (13.5%), and accident (9.5%). Fatalities were divided near evenly between combatants (52.7%) and support personnel (47.3%), and between battle injury (51.4%) and disease and nonbattle injury (48.6%). Natural and suicide death was higher (p < 0.01, 0.02) among support personnel who were older (p = 0.05) with more reserve/national guard personnel (p = 0.01). Total population prevalence of underlying atherosclerosis was 18.9%, with more among support personnel (64.3%). Of 46 nonsuicide trauma fatalities, most died of blast injury (67.4%) followed by gunshot wound (26.1%) and multiple/blunt force injury (6.5%). The leading mechanism of death was catastrophic tissue destruction (82.6%). Most had nonsurvivable injuries (82.6%) and nonpreventable deaths (93.5%). CONCLUSION: Operation New Dawn fatalities were exclusively conventional forces divided between combatants and support personnel, the former succumbing more to battle injury and the latter to disease and nonbattle injury including self-inflicted injury. For nonsuicide trauma fatalities, none died from a survivable injury, and 17.4% died from potentially survivable injuries. Opportunities for improvement included providing earlier blood products and surgery. LEVEL OF EVIDENCE: Therapeutic, level V and epidemiological, level IV.

Case-control analysis of prehospital death and prolonged field care survival during recent US military combat operations.

BACKGROUND: Quantification of medical interventions administered during prolonged field care (PFC) is necessary to inform training and planning. MATERIALS AND METHODS: Retrospective cohort study of Department of Defense Trauma Registry casualties with maximum Abbreviated Injury Scale (MAIS) score of 2 or greater and prehospital records during combat operations 2007 to 2015; US military nonsurvivors were linked to Armed Forces Medical Examiner System data. Medical interventions administered to survivors of 4 hours to 72 hours of PFC and nonsurvivors who died prehospital were compared by frequency-matching on mechanism (explosive, firearm, other), injury type (penetrating, blunt) and injured body regions with MAIS score of 3 or greater. Covariates for adjustment included age, sex, military Service, shock, Glasgow Coma Scale, transport team, MAIS and Injury Severity Score (ISS). Sensitivity analysis focused on US military subgroup with AIS/ISS assigned to nonsurvivors after autopsy. RESULTS: The total inception cohort included 16,202 casualties (5,269 US military, 10,809 non-US military), 64% Afghanistan, 36% Iraq. Of US military, 734 deaths occurred within 30 days, nearly 90% occurred within 4 hours of injury. There were 3,222 casualties (1,111 US military, 2,111 non-US military) documented for prehospital care and died prehospital (691) or survived 4 hours to 72 hours of PFC (2,531). Twenty-five percent (815/3,222) received advanced airway, 18% (583) ventilatory support, 9% (281) tourniquet. Twenty-three percent (725) received blood transfusions within 24 hours. Of the matched cohort (1,233 survivors, 490 nonsurvivors), differences were observed in care (survivors received more warming, intravenous fluids, sedation, mechanical ventilation, narcotics, antibiotics; nonsurvivors received more intubations, tourniquets, intraosseous fluids, cardiopulmonary resuscitation). Sensitivity analysis focused on US military (732 survivors, 379 nonsurvivors) showed no significant differences in prehospital interventions. Without autopsy information, the ISS of nonsurvivors significantly underestimated injury severity. CONCLUSION: Tourniquets, blood transfusion, airway, and ventilatory support are frequently required interventions for the seriously injured. Prolonged field care should direct resources, technology, and training to field technology for sustained resuscitation, airway, and breathing support in the austere environment. LEVEL OF EVIDENCE: Prognostic, Level III.

Autopsy-Determined Atherosclerosis in Elite US Military Special Operations Forces.

BACKGROUND: Autopsy studies of trauma fatalities have provided evidence for the pervasiveness of atherosclerosis in young and middle-aged adults. The objective of this study was to determine the prevalence of atherosclerosis in elite US military forces. METHODS: We conducted a retrospective study of all US Special Operations Command (USSOCOM) fatalities from 2001 to 2020 who died from battle injuries. Autopsies were evaluated from Afghanistan- and Iraq-centric combat operations for evidence of coronary and/or aortic atherosclerosis and categorized as minimal (fatty streaking only), moderate (10-49% narrowing of ≥1 vessel), and severe (≥50% narrowing of ≥1 vessel). Prevalence of atherosclerosis was determined for the total population and by subgroup characteristics of age, sex, race/ethnicity, combat operation, service command, occupation, rank, cause of death, manner of death, and body mass index (BMI). RESULTS: From the total of 388 USSOCOM battle injury fatalities, 356 were included in the analysis. The mean age was 31 years (range, 19-57 years), and 98.6% were male. The overall prevalence of coronary and/or aortic atherosclerosis was 17.4%. The prevalence of coronary atherosclerosis alone was 13.8%. Coronary atherosclerosis was categorized as minimal in 1.1%, moderate in 7.6%, and severe in 5.1%. Of those with atherosclerosis, 24.2% were <30 years old, 88.7% were from enlisted ranks, and 95.2% had combatant occupations. When BMI could be calculated, 73.5% of fatalities with atherosclerosis had a BMI =25. CONCLUSIONS: Autopsy-determined atherosclerosis is prevalent in elite US military Special Operations Forces despite young age and positive lifestyle benefits of service in an elite military unit.

Establishing an enduring Military Trauma Mortality Review: Misconceptions and lessons learned.

Under direction from the Defense Health Agency, subject matter experts (SMEs) from the Joint Trauma System, Armed Forces Medical Examiner System, and civilian sector established the Military Trauma Mortality Review process. To establish the most empirically robust process, these SMEs used both qualitative and quantitative methods published in a series of peer-reviewed articles over the last 3 years. Most recently, the Military Mortality Review process was implemented for the first time on all battle-injured service members attached to the United States Special Operations Command from 2001 to 2018. The current Military Mortality Review process builds on the strengths and limitations of important previous work from both the military and civilian sector. To prospectively improve the trauma care system and drive preventable death to the lowest level possible, we present the main misconceptions and lessons learned from our 3-year effort to establish a reliable and sustainable Military Trauma Mortality Review process. These lessons include the following: (1) requirement to use standardized and appropriate lexicon, definitions, and criteria; (2) requirement to use a combination of objective injury scoring systems, forensic information, and thorough SME case review to make injury survivability and death preventability determinations; (3) requirement to use nonmedical information to make reliable death preventability determinations and a comprehensive list of opportunities for improvement to reduce preventable deaths within the trauma care system; and (4) acknowledgment that the military health system still has gaps in current infrastructure that must be addressed to globally and continuously implement the process outlined in the Military Trauma Mortality Review process in the future. LEVEL OF EVIDENCE: Level III.

United States Special Operations Command fatality study of subcommands, units, and trends.

BACKGROUND: Death from injury occurs predominantly in prehospital settings. Injury prevention and prehospital care of military forces is the responsibility of combatant commanders. Medical examiner and trauma systems should routinely study fatalities and inform commanders of mortality trends. METHODS: Data reported on US Special Operations Command (USSOCOM) fatalities who died while performing duties from September 11, 2001, to September 10, 2018, were reevaluated to compare subcommands, units, and trends. Injury was assessed by mechanism, severity, operational posture, and survivability. Death was assessed by manner, cause, classification, mechanism, and preventability. RESULTS: Of 614 USSOCOM fatalities (median age, 30 years; male, 98.5%), 67.6% occurred in the Army command, of which 49.2% occurred in the Special Forces command. Battle injury accounted for 60.1% of USSOCOM fatalities. Most battle-injured fatalities in each subcommand had nonsurvivable injuries and nonpreventable deaths. For each subcommand except Marine Corps, fatalities with nonsurvivable injuries sustained injuries primarily while mounted. By subcommand, the primary cause of death for fatalities with nonsurvivable injuries was blast for Army (57.6%), multiple/blunt force for Navy (60.0%), gunshot wound for Air Force (55.6%), and split between blast (50.0%) and gunshot wound (50.0%) for Marine Corps. For each subcommand except Air Force, fatalities with potentially survivable-survivable injuries sustained injuries primarily while dismounted, and the mechanism of death was primarily hemorrhage plus other mechanism or hemorrhage alone. Hemorrhage only mechanism of death was surpassed over time by complex multimechanism death. Potential for injury survivability and death preventability was greatest during early and later years of conflict. CONCLUSION: Organizational differences in mortality characteristics and trends were identified from which commanders can refine efforts to prevent and treat injury and improve survival. Fatality analyses inform operational risk matrices and advance casualty prevention and response efforts. Prevention, assessment, and treatment strategies must evolve to reduce death from hemorrhage plus coexisting mechanisms. LEVEL OF EVIDENCE: Performance Improvement and Epidemiological, level IV.

Mortality review of US Special Operations Command battle-injured fatalities.

BACKGROUND: Comprehensive analyses of battle-injured fatalities, incorporating a multidisciplinary process with a standardized lexicon, is necessary to elucidate opportunities for improvement (OFIs) to increase survivability. METHODS: A mortality review was conducted on United States Special Operations Command battle-injured fatalities who died from September 11, 2001, to September 10, 2018. Fatalities were analyzed by demographics, operational posture, mechanism of injury, cause of death, mechanism of death (MOD), classification of death, and injury severity. Injury survivability was determined by a subject matter expert panel and compared with injury patterns among Department of Defense Trauma Registry survivors. Death preventability and OFI were determined for fatalities with potentially survivable or survivable (PS-S) injuries using tactical data and documented medical interventions. RESULTS: Of 369 United States Special Operations Command battle-injured fatalities (median age, 29 years; male, 98.6%), most were killed in action (89.4%) and more than half died from injuries sustained during mounted operations (52.3%). The cause of death was blast injury (45.0%), gunshot wound (39.8%), and multiple/blunt force injury (15.2%). The leading MOD was catastrophic tissue destruction (73.7%). Most fatalities sustained nonsurvivable injuries (74.3%). For fatalities with PS-S injuries, most had hemorrhage as a component of MOD (88.4%); however, the MOD was multifactorial in the majority of these fatalities (58.9%). Only 5.4% of all fatalities and 21.1% of fatalities with PS-S injuries had comparable injury patterns among survivors. Accounting for tactical situation, a minority of deaths were potentially preventable (5.7%) and a few preventable (1.1%). Time to surgery (93.7%) and prehospital blood transfusion (89.5%) were the leading OFI for PS-S fatalities. Most fatalities with PS-S injuries requiring blood (83.5%) also had an additional prehospital OFI. CONCLUSION: Comprehensive mortality reviews of battlefield fatalities can identify OFI in combat casualty care and prevention. Standardized lexicon is essential for translation to civilian trauma systems. LEVEL OF EVIDENCE: Epidemiological, level IV.

Nonfatal motor vehicle related injuries among deployed US Service members: Characteristics, trends, and risks for limb amputations.

BACKGROUND: Motor vehicle-related (MVR) incidents are important causes of morbidity among deployed US service members (SMs). Nonbattle MVR injuries are usually similar to civilian MVR injuries, while battle MVR injuries are often unique due to the blast effects from precipitating explosive mechanisms. Our primary objective was to describe the characteristics and trends of nonfatal MVR injuries sustained by deployed US SMs. A second objective was to assess the association between mechanism of injury (i.e., explosive vs. nonexplosive) and limb amputation. METHODS: We conducted a retrospective cross-sectional analysis using data from the Department of Defense Trauma Registry collected from October 2001 to December 2018. Descriptive statistics were reported stratified by mechanism of injury (explosive vs. nonexplosive). The association between mechanism of injury and limb amputation was assessed using logistic regression models. RESULTS: There were 3,119 US casualties who sustained nonfatal MVR injuries, 2,380 (76.3%) SMs sustained nonexplosive MVR injuries while 739 (23.7%) sustained explosive MVR injuries. Of all MVR casualties, 2,085 (66.9%) were in Iraq or Syria and 1034 (33.1%) in Afghanistan. The annual prevalence of nonfatal MVR battle casualties was highest in Iraq and Syria from 2003 to 2009 and Afghanistan from 2009 to 2014, ranging overall 15 to 50 MVR casualties per 1,000 wounded in action. There were 92 limb amputations associated with MVR incidents. Compared with nonexplosive MVR mechanisms, explosive MVR mechanisms had higher association with limb amputation (adjusted odds ratio, 2.6; confidence interval, 1.7-3.9), even after adjusting for injury year and Injury Severity Score (AOR, 2.1; confidence interval: 1.4-3.4). CONCLUSION: Motor vehicle-related incidents are an important cause of injury in US military operations. Compared with nonexplosive MVR incidents, explosive MVR incidents result in more severe injuries, and have a higher associated risk of limb amputation. Continued efforts to improve injury prevention through protective equipment and medical training specific to MVR injuries are needed. LEVEL OF EVIDENCE: Prognostic and epidemiological study, Level III.

Patterns of Anatomic Injury in Critically Injured Combat Casualties: A Network Analysis.

A mortality review of death caused by injury requires a determination of injury survivability prior to a determination of death preventability. If injuries are nonsurvivable, only non-medical primary prevention strategies have potential to prevent the death. Therefore, objective measures are needed to empirically inform injury survivability from complex anatomic patterns of injury. As a component of injury mortality reviews, network structures show promise to objectively elucidate survivability from complex anatomic patterns of injury resulting from explosive and firearm mechanisms. In this network analysis of 5,703 critically injured combat casualties, patterns of injury among fatalities from explosive mechanisms were associated with both a higher number and severity of anatomic injuries to regions such as the extremities, abdomen, and thorax. Patterns of injuries from a firearm were more isolated to individual body regions with fatal patterns involving more severe injuries to the head and thorax. Each injury generates a specific level of risk as part of an overall anatomic pattern to inform injury survivability not always captured by traditional trauma scoring systems. Network models have potential to further elucidate differences between potentially survivable and nonsurvivable anatomic patterns of injury as part of the mortality review process relevant to improving both the military and civilian trauma care systems.

A descriptive study of US Special Operations Command fatalities, 2001 to 2018.

BACKGROUND: Studies of fatalities from injury and disease guide prevention and treatment efforts for populations at risk. Findings can inform leadership and direct clinical practice guidelines, research, and personnel, training, and equipment requirements. METHODS: A retrospective review and descriptive analysis was conducted of United States Special Operations Command (USSOCOM) fatalities who died while performing duties from September 11, 2001, to September 10, 2018. Characteristics analyzed included subcommand, military activity, operational posture, and manner of death. RESULTS: Of 614 USSOCOM fatalities (median age, 30 years; male, 98.5%) the leading cause of death was injury (97.7%); specifically, multiple/blunt force injury (34.5%), blast injury (30.7%), gunshot wound (GSW; 30.3%), and other (4.5%). Most died outside the United States (87.1%), during combat operations (85.3%), in the prehospital environment (91.5%), and the same day of insult (90.4%). Most fatalities were with the US Army Special Operations Command (67.6%), followed by the Naval Special Warfare Command (16.0%), Air Force Special Operations Command (9.3%), and Marine Corps Forces Special Operations Command (7.2%). Of 54.6% who died of injuries incurred during mounted operations, most were on ground vehicles (53.7%), followed by rotary-wing (37.3%) and fixed-wing (9.0%) aircrafts. The manner of death was primarily homicide (66.0%) and accident (30.5%), followed by natural (2.1%), suicide (0.8%), and undetermined (0.7%). Specific homicide causes of death were GSW (43.7%), blast injury (42.2%), multiple/blunt force injury (13.8%), and other (0.2%). Specific accident causes of death were multiple/blunt force injury (80.7%), blast injury (6.4%), GSW (0.5%), and other (12.3%). Of accident fatalities with multiple/blunt force injury, the mechanism was mostly aircraft mishaps (62.9%), particularly rotary wing (68.4%). CONCLUSION: Most USSOCOM fatalities died abroad from injury in the prehospital setting. To improve survival from military activities worldwide, leaders must continue to optimize prehospital capability and develop strategies that rapidly connect patients to advanced resuscitative and surgical care. LEVEL OF EVIDENCE: Epidemiological, level IV; Therapeutic level IV.

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

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.

Prominent Injury Types in Vehicle Underbody Blast.

BACKGROUND: To fully understand the injury mechanisms during an underbody blast (UBB) event with military vehicles and develop new testing standards specific to military vehicles, one must understand the injuries sustained by the occupants. METHODS: Injury data from Service Members (SM) involved in UBB theater events that occurred from 2010 to 2014 were analyzed. Analysis included the investigation of prominent skeletal and visceral torso injuries. Results were categorized by killed-in-action (n = 132 SM) and wounded-in-action (n = 1,887 SM). RESULTS: Over 90% (553/606 SM) of casualties in UBB events with Abbreviated Injury Scale (AIS) 2+ injury sustained at least one skeletal fracture, when excluding concussion. The most frequent skeletal injuries from UBB were foot fractures (13% of injuries) for wounded-in-action and tibia/fibula fractures (10% of injuries) for killed-in-action. Only 1% (11/1037 SM) of all casualties with AIS 2+ injuries had visceral torso injuries without also sustaining skeletal fractures. In these few casualties, the coded injuries were likely due to trauma from a loading path other than direct UBB loading. CONCLUSION: Skeletal fractures are the most frequent AIS 2+ injury resulting from UBB events. Visceral torso injuries are infrequent in individuals that survive and they generally occur in conjunction with skeletal injuries.

Management of Suspected Tension Pneumothorax in Tactical Combat Casualty Care: TCCC Guidelines Change 17-02.

This change to the Tactical Combat Casualty Care (TCCC) Guidelines that updates the recommendations for management of suspected tension pneumothorax for combat casualties in the prehospital setting does the following things: (1) Continues the aggressive approach to suspecting and treating tension pneumothorax based on mechanism of injury and respiratory distress that TCCC has advocated for in the past, as opposed to waiting until shock develops as a result of the tension pneumothorax before treating. The new wording does, however, emphasize that shock and cardiac arrest may ensue if the tension pneumothorax is not treated promptly. (2) Adds additional emphasis to the importance of the current TCCC recommendation to perform needle decompression (NDC) on both sides of the chest on a combat casualty with torso trauma who suffers a traumatic cardiac arrest before reaching a medical treatment facility. (3) Adds a 10-gauge, 3.25-in needle/ catheter unit as an alternative to the previously recommended 14-gauge, 3.25-in needle/catheter unit as recommended devices for needle decompression. (4) Designates the location at which NDC should be performed as either the lateral site (fifth intercostal space [ICS] at the anterior axillary line [AAL]) or the anterior site (second ICS at the midclavicular line [MCL]). For the reasons enumerated in the body of the change report, participants on the 14 December 2017 TCCC Working Group teleconference favored including both potential sites for NDC without specifying a preferred site. (5) Adds two key elements to the description of the NDC procedure: insert the needle/ catheter unit at a perpendicular angle to the chest wall all the way to the hub, then hold the needle/catheter unit in place for 5 to 10 seconds before removing the needle in order to allow for full decompression of the pleural space to occur. (6) Defines what constitutes a successful NDC, using specific metrics such as: an observed hiss of air escaping from the chest during the NDC procedure; a decrease in respiratory distress; an increase in hemoglobin oxygen saturation; and/or an improvement in signs of shock that may be present. (7) Recommends that only two needle decompressions be attempted before continuing on to the "Circulation" portion of the TCCC Guidelines. After two NDCs have been performed, the combat medical provider should proceed to the fourth element in the "MARCH" algorithm and evaluate/treat the casualty for shock as outlined in the Circulation section of the TCCC Guidelines. Eastridge's landmark 2012 report documented that noncompressible hemorrhage caused many more combat fatalities than tension pneumothorax.1 Since the manifestations of hemorrhagic shock and shock from tension pneumothorax may be similar, the TCCC Guidelines now recommend proceeding to treatment for hemorrhagic shock (when present) after two NDCs have been performed. (8) Adds a paragraph to the end of the Circulation section of the TCCC Guidelines that calls for consideration of untreated tension pneumothorax as a potential cause for shock that has not responded to fluid resuscitation. This is an important aspect of treating shock in combat casualties that was not presently addressed in the TCCC Guidelines. (9) Adds finger thoracostomy (simple thoracostomy) and chest tubes as additional treatment options to treat suspected tension pneumothorax when further treatment is deemed necessary after two unsuccessful NDC attempts-if the combat medical provider has the skills, experience, and authorizations to perform these advanced interventions and the casualty is in shock. These two more invasive procedures are recommended only when the casualty is in refractory shock, not as the initial treatment.

A US military Role 2 forward surgical team database study of combat mortality in Afghanistan.

BACKGROUND: Timely and optimal care can reduce mortality among critically injured combat casualties. US military Role 2 surgical teams were deployed to forward positions in Afghanistan on behalf of the battlefield trauma system. They received prehospital casualties, provided early damage control resuscitation and surgery, and rapidly transferred casualties to Role 3 hospitals for definitive care. A database was developed to capture Role 2 data. METHODS: A retrospective review and descriptive analysis were conducted of battle-injured casualties transported to US Role 2 surgical facilities in Afghanistan from February 2008 to September 2014. Casualties were analyzed by mortality status and location of death (pretransport, intratransport, or posttransport), military affiliation, transport time, injury type and mechanism, combat mortality index-prehospital (CMI-PH), and documented prehospital treatment. RESULTS: Of 9,557 casualties (median age, 25.0 years; male, 97.4%), most (95.1%) survived to transfer from Role 2 facility care. Military affiliation included US coalition forces (37.4%), Afghanistan National Security Forces (23.8%), civilian/other forces (21.3%), Afghanistan National Police (13.5%), and non-US coalition forces (4.0%). Mortality differed by military affiliation (p < 0.001). Among fatalities, most were Afghanistan National Security Forces (30.5%) civilian/other forces (26.0%), or US coalition forces (25.2%). Of those categorized by CMI-PH, 40.0% of critical, 11.2% of severe, 0.8% of moderate, and less than 0.1% of mild casualties died. Most fatalities with CMI-PH were categorized as critical (66.3%) or severe (25.9%), whereas most who lived were mild (56.9%) or moderate (25.4%). Of all fatalities, 14.0% died prehospital (pretransport, 5.8%; intratransport, 8.2%), and 86.0% died at a Role 2 facility (posttransport). Of fatalities with documented transport times (median, 53.0 minutes), most (61.7%) were evacuated within 60 minutes. CONCLUSIONS: Role 2 surgical team care has been an important early component of the battlefield trauma system in Afghanistan. Combat casualty care must be documented, collected, and analyzed for outcomes and trends to improve performance. LEVEL OF EVIDENCE: Therapeutic/Care Management, level IV.

Suicide Rates Among Active Duty Service Members Compared with Civilian Counterparts, 2005-2014.

The objective of this study was to compare military suicide rates with civilian suicide rates, adjusting for age and sex differences that exist between the two populations. The number of active component (AC) service members whose manner of death was certified as suicide was determined for specific age and sex groups for each year from 2005 to 2014. Indirect standardization was then used to determine the expected number of suicides for each age/sex group, based on the U.S. suicide rates for the corresponding age/sex groups obtained from the Centers for Disease Control and Prevention's Web-based Injury Statistics Query and Reporting System. Although suicide rates among U.S. active duty Service Members were found to increase between 2005 and 2009, overall age- and sex-adjusted AC suicide rates were lower than or comparable to civilian rates every year of the study period. When suicide numbers were analyzed within specific age and sex categories, there was a significant association between higher suicide incidence and AC military status for 17-29-yr-old females in 2010, 2012, and 2014, and a significant association between lower suicide incidence and AC military status for 25-49 -yr-old males in some years.

Comparison of Military and Civilian Methods for Determining Potentially Preventable Deaths: A Systematic Review.

Importance: Military and civilian trauma experts initiated a collaborative effort to develop an integrated learning trauma system to reduce preventable morbidity and mortality. Because the Department of Defense does not currently have recommended guidelines and standard operating procedures to perform military preventable death reviews in a consistent manner, these performance improvement processes must be developed. Objectives: To compare military and civilian preventable death determination methods to understand the existing best practices for evaluating preventable death. Evidence Review: This systematic review followed the PRISMA reporting guidelines. English-language articles were searched from inception to February 15, 2017, using the following databases: MEDLINE (Ovid), Evidence-Based Medicine Reviews (Ovid), PubMed, CINAHL, and Google Scholar. Articles were initially screened for eligibility and excluded based on predetermined criteria. Articles reviewing only prehospital deaths, only inhospital deaths, or both were eligible for inclusion. Information on study characteristics was independently abstracted by 2 investigators. Reported are methodological factors affecting the reliability of preventable death studies and the preventable death rate, defined as the number of potentially preventable deaths divided by the total number of deaths within a specific patient population. Findings: Fifty studies (8 military and 42 civilian) met the inclusion criteria. In total, 1598 of 6500 military deaths reviewed and 3346 of 19 108 civilian deaths reviewed were classified as potentially preventable. Among military studies, the preventable death rate ranged from 3.1% to 51.4%. Among civilian studies, the preventable death rate ranged from 2.5% to 85.3%. The high level of methodological heterogeneity regarding factors, such as preventable death definitions, review process, and determination criteria, hinders a meaningful quantitative comparison of preventable death rates. Conclusions and Relevance: The reliability of military and civilian preventable death studies is hindered by inconsistent definitions, incompatible criteria, and the overall heterogeneity in study methods. The complexity, inconsistency, and unpredictability of combat require unique considerations to perform a methodologically sound combat-related preventable death review. As the Department of Defense begins the process of developing recommended guidelines and standard operating procedures for performing military preventable death reviews, consideration must be given to the factors known to increase the risk of bias and poor reliability.