Brian J. Eastridge

Death on the battlefield (2001-2011): implications for the future of combat casualty care.

BACKGROUND Critical evaluation of all aspects of combat casualty care, including mortality, with a special focus on the incidence and causes of potentially preventable deaths among US combat fatalities, is central to identifying gaps in knowledge, training, equipment, and execution of battlefield trauma care. The impetus to produce this analysis was to develop a comprehensive perspective of battlefield death, concentrating on deaths that occurred in the pre–medical treatment facility (pre-MTF) environment. METHODS The Armed Forces Medical Examiner Service Mortality Surveillance Division was used to identify Operation Iraqi Freedom and Operation Enduring Freedom combat casualties from October 2001 to June 2011 who died from injury in the deployed environment. The autopsy records, perimortem records, photographs on file, and Mortality Trauma Registry of the Armed Forces Medical Examiner Service were used to compile mechanism of injury, cause of injury, medical intervention performed, Abbreviated Injury Scale (AIS) score, and Injury Severity Score (ISS) on all lethal injuries. All data were used by the expert panel for the conduct of the potential for injury survivability assessment of this study. RESULTS For the study interval between October 2001 and June 2011, 4,596 battlefield fatalities were reviewed and analyzed. The stratification of mortality demonstrated that 87.3% of all injury mortality occurred in the pre-MTF environment. Of the pre-MTF deaths, 75.7% (n = 3,040) were classified as nonsurvivable, and 24.3% (n = 976) were deemed potentially survivable (PS). The injury/physiologic focus of PS acute mortality was largely associated with hemorrhage (90.9%). The site of lethal hemorrhage was truncal (67.3%), followed by junctional (19.2%) and peripheral-extremity (13.5%) hemorrhage. CONCLUSION Most battlefield casualties died of their injuries before ever reaching a surgeon. As most pre-MTF deaths are nonsurvivable, mitigation strategies to impact outcomes in this population need to be directed toward injury prevention. To significantly impact the outcome of combat casualties with PS injury, strategies must be developed to mitigate hemorrhage and optimize airway management or reduce the time interval between the battlefield point of injury and surgical intervention. Understanding battlefield mortality is a vital component of the military trauma system. Emphasis on this analysis should be placed on trauma system optimization, evidence-based improvements in Tactical Combat Casualty Care guidelines, data-driven research, and development to remediate gaps in care and relevant training and equipment enhancements that will increase the survivability of the fighting force.

Died of Wounds on the Battlefield: Causation and Implications for Improving Combat Casualty Care

BACKGROUND Understanding the epidemiology of death after battlefield injury is vital to combat casualty care performance improvement. The current analysis was undertaken to develop a comprehensive perspective of deaths that occurred after casualties reached a medical treatment facility. METHODS Battle injury died of wounds (DOW) deaths that occurred after casualties reached a medical treatment facility from October 2001 to June 2009 were evaluated by reviewing autopsy and other postmortem records at the Office of the Armed Forces Medical Examiners (OAFME). A panel of military trauma experts classified the injuries as nonsurvivable (NS) or potentially survivable (PS), in consultation with an OAFME forensic pathologist. Data including demographics, mechanism of injury, physiologic and laboratory variables, and cause of death were obtained from the Joint Theater Trauma Registry and the OAFME Mortality Trauma Registry. RESULTS DOW casualties (n = 558) accounted for 4.56% of the nonreturn to duty battle injuries over the study period. DOW casualties were classified as NS in 271 (48.6%) cases and PS in 287 (51.4%) cases. Traumatic brain injury was the predominant injury leading to death in 225 of 271 (83%) NS cases, whereas hemorrhage from major trauma was the predominant mechanism of death in 230 of 287 (80%) PS cases. In the hemorrhage mechanism PS cases, the major body region bleeding focus accounting for mortality were torso (48%), extremity (31%), and junctional (neck, axilla, and groin) (21%). Fifty-one percent of DOW casualties presented in extremis with cardiopulmonary resuscitation upon presentation. CONCLUSIONS Hemorrhage is a major mechanism of death in PS combat injuries, underscoring the necessity for initiatives to mitigate bleeding, particularly in the prehospital environment.

The Epidemiology of Vascular Injury in the Wars in Iraq and Afghanistan

Background:Blood vessel trauma leading to hemorrhage or ischemia presents a significant cause of morbidity and mortality after battlefield injury. The objective of this study is to characterize the epidemiology of vascular injury in the wars of Iraq and Afghanistan, including categorization of anatomic patterns, mechanism, and management of casualties. Methods:The Joint Theater Trauma Registry was interrogated (2002–2009) for vascular injury in US troops to identify specific injury (group 1) and operative intervention (group 2) groups. Battle-related injuries (nonreturn to duty) were used as the denominator to establish injury rates. Mechanism of injury was compared between theaters of war and the management strategies of ligation versus revascularization (repair and interposition grafting) reported. Results:Group 1 included 1570 Troops injured in Iraq (OIF) (n = 1390) and Afghanistan (OEF) (n = 180). Mechanism included explosive (73%), gunshot (27%), and other (<1%) with explosive more common in OIF than OEF (P < 0.05). During this period, 13,076 battle-related injuries occurred resulting in a specific rate of 12% (1570 of 13,076), which was higher in OIF than OEF (12.5% vs 9% respectively; P < 0.05). Of group 1, 60% (n = 940) sustained injury to major or proximal vessels and 40% (n = 630) to minor or distal vessels (unknown vessel, n = 27). Group 2 (operative) comprised 1212 troops defining an operative rate of 9% (1212 of 13,076) and included ligation (n = 660; 54%) or repair (n = 552; 46%). Peak rates in OIF and OEF occurred in November 2004 (15%) and August 2009 (11%), respectively and correlated with combat operational tempo. Conclusion:The rate of vascular injury in modern combat is 5 times that reported in previous wars and varies according to theater of war, mechanism of injury and operational tempo. Methods of reconstruction are now applied to nearly half of the vascular injuries and should be a focus of training for combat surgery. Selective ligation of vascular injury remains an important management strategy, especially for minor or distal vessel injuries.

Improved characterization of combat injury

BACKGROUND Combat injury patterns differ from civilian trauma in that the former are largely explosion-related, comprising multiple mechanistic and fragment injuries and high-kinetic-energy bullets. Further, unlike civilians, U.S. armed forces combatants are usually heavily protected with helmets and Kevlar body armor with ceramic plate inserts. Searchable databases providing actionable, statistically valid knowledge of body surface entry wounds and resulting organ injury severity are essential to understanding combat trauma. METHODS Two tools were developed to address these unique aspects of combat injury: (1) the Surface Wound Mapping (SWM) database and Surface Wound Analysis Tool (SWAT) software that were developed to generate 3D density maps of point-of-surface wound entry and resultant anatomic injury severity; and (2) the Abbreviated Injury Scale (AIS) 2005-Military that was developed by a panel of military trauma surgeons to account for multiple injury etiology from explosions and other high-kinetic- energy weapons. Combined data from the Joint Theater Trauma Registry, Navy/Marine Combat Trauma Registry, and the Armed Forces Medical Examiner System Mortality Trauma Registry were coded in AIS 2005-Military, entered into the SWM database, and analyzed for entrance site and wounding path. RESULTS When data on 1,151 patients, who had a total of 3,500 surface wounds and 12,889 injuries, were entered into SWM, surface wounds averaged 3.0 per casualty and injuries averaged 11.2 per casualty. Of the 3,500 surface wounds, 2,496 (71%) were entrance wounds with 6,631 (51%) associated internal injuries, with 2.2 entrance wounds and 5.8 associated injuries per casualty (some details cannot be given because of operational security). Crude deaths rates were calculated using Maximum AIS-Military. CONCLUSION These new tools have been successfully implemented to describe combat injury, mortality, and distribution of wounds and associated injuries. AIS 2005-Military is a more precise assignment of severity to military injuries. SWM has brought data from all three combat registries together into one analyzable database. SWM and SWAT allow visualization of wounds and associated injuries by region on a 3D model of the body.

Impact of joint theater trauma system initiatives on battlefield injury outcomes

INTRODUCTION The US military forces developed and implemented the Joint Theater Trauma System (JTTS) and Joint Theater Trauma Registry (JTTR) using US civilian trauma system models with the intent of improving outcomes after battlefield injury. METHODS The purpose of this analysis was to elaborate the impact of the JTTS. To quantify these achievements, the JTTR captured mechanism, acute physiology, diagnostic, therapeutic, and outcome data on 23,250 injured patients admitted to deployed US military treatment facilities from July 2003 through July 2008 for analysis. Comparative analysis to civilian trauma systems was done using the National Trauma Data Bank (NTDB). RESULTS In contrast to civilian trauma systems with an 11.1% rate of penetrating injury, 68.3% of battlefield wounds were by penetrating mechanism. In the analyzed cohort, 23.3% of all patients had an Injury Severe Score (ISS) > or = 16, which is similar to the civilian rate of 22.4%. In the military injury population, 66% of injuries were combat-related. In addition, in the military injury group, 21.8% had metabolic evidence of shock with a base deficit > or = 5, 29.8% of patients required blood transfusion, and 6.4% of the total population of combat casualties required massive transfusion (>10 U red blood cells/24 hours). With this complex and severely injured population of battlefield injuries, the JTTS elements were used to recognize and remedy more than 60 trauma system issues requiring leadership and advocacy, education, research, and alterations in clinical care. Of particular importance to the trauma system was the implementation and tracking of performance improvement indicators and the dissemination of 27 evidence-based clinical practice guidelines (CPGs). In particular, the damage control resuscitation guideline was associated with a decrease in mortality in the massively transfused from 32% pre-CPG to 21% post-CPG. As evidence of the effectiveness of the JTTS, a mortality rate of 5.2% after battlefield hospital admission is comparable to a case fatality rate of 4.3% reported in an age-matched cohort from the NTDB. CONCLUSIONS JTTS initiatives contributed to improved survival after battlefield injury. The JTTS has set the standard of trauma care for the modern battlefield using contemporary systems-based methodologies.

Prevention of infections associated with combat-related extremity injuries

During combat operations, extremities continue to be the most common sites of injury with associated high rates of infectious complications. Overall, ∼ 15% of patients with extremity injuries develop osteomyelitis, and ∼ 17% of those infections relapse or recur. The bacteria infecting these wounds have included multidrug-resistant bacteria such as Acinetobacter baumannii, Pseudomonas aeruginosa, extended-spectrum β-lactamase-producing Klebsiella species and Escherichia coli, and methicillin-resistant Staphylococcus aureus. The goals of extremity injury care are to prevent infection, promote fracture healing, and restore function. In this review, we use a systematic assessment of military and civilian extremity trauma data to provide evidence-based recommendations for the varying management strategies to care for combat-related extremity injuries to decrease infection rates. We emphasize postinjury antimicrobial therapy, debridement and irrigation, and surgical wound management including addressing ongoing areas of controversy and needed research. In addition, we address adjuvants that are increasingly being examined, including local antimicrobial therapy, flap closure, oxygen therapy, negative pressure wound therapy, and wound effluent characterization. This evidence-based medicine review was produced to support the Guidelines for the Prevention of Infections Associated With Combat-Related Injuries: 2011 Update contained in this supplement of Journal of Trauma.

Guidelines for the prevention of infections associated with combat-related injuries: 2011 update endorsed by the infectious diseases society of America and the surgical infection society

Despite advances in resuscitation and surgical management of combat wounds, infection remains a concerning and potentially preventable complication of combat-related injuries. Interventions currently used to prevent these infections have not been either clearly defined or subjected to rigorous clinical trials. Current infection prevention measures and wound management practices are derived from retrospective review of wartime experiences, from civilian trauma data, and from in vitro and animal data. This update to the guidelines published in 2008 incorporates evidence that has become available since 2007. These guidelines focus on care provided within hours to days of injury, chiefly within the combat zone, to those combat-injured patients with open wounds or burns. New in this update are a consolidation of antimicrobial agent recommendations to a backbone of high-dose cefazolin with or without metronidazole for most postinjury indications, and recommendations for redosing of antimicrobial agents, for use of negative pressure wound therapy, and for oxygen supplementation in flight.

Fresh whole blood use by forward surgical teams in Afghanistan is associated with improved survival compared to component therapy without platelets

In Afghanistan, a substantial portion of resuscitative combat surgery is performed by US Army forward surgical teams (FSTs). Red blood cells (RBCs) and fresh frozen plasma (FFP) are available at these facilities, but platelets are not. FST personnel frequently encounter high‐acuity patient scenarios without the ability to transfuse platelets. An analysis of the use of fresh whole blood (FWB) at FSTs therefore allows for an evaluation of outcomes associated with this practice.

Joint Theater Trauma System implementation of burn resuscitation guidelines improves outcomes in severely burned military casualties.

BACKGROUND Between March 2003 and June 2007, our burn center received 594 casualties from the conflicts in Iraq and Afghanistan. Ongoing acute burn resuscitation as severely burned casualties are evacuated over continents is very challenging. To help standardize care, burn resuscitation guidelines (BRG) were devised along with a burn flow sheet (BFS) and disseminated via the new operational Joint Theater Trauma System to assist deployed providers. METHODS After the BRG was implemented in January 2006, BRF data were prospectively collected in consecutive military casualties with >30% total body surface area (TBSA) burns (BRG Group). Baseline demographic data and fluid requirements for the first 24 hours of the burn resuscitation were collected from the BFS. Percentage full thickness TBSA burns, presence of inhalation injury, injury severity score, resuscitation-related abdominal compartment syndrome, and mortality were collected from our database. Individual charts were reviewed to determine the presence of extremity fasciotomies and myonecrosis. These results were compared with consecutive military casualties admitted during the 2-year- period before the system-wide implementation of the BRG (control group). RESULTS One hundred eighteen military casualties with burns >30% TBSA were admitted between January 2003 and June 2007, with n = 56 in the BRG group and n = 62 in the control group. The groups were different in age, but similar in %TBSA, %full thickness, presence of inhalation injury, and injury severity score. There was no difference in the rate of extremity fasciotomies or the incidence of myonecrosis between groups. CONCLUSIONS The composite endpoint of abdominal compartment syndrome and mortality was significantly lower in the BRG group compared with the control group (p = 0.03). Implementation of the BRG and system-wide standardization of burn resuscitation improved outcomes in severely burned patients. Utilization of the joint theater trauma system to implement system-wide guidelines is effective and can help improve outcomes.

Infections complicating the care of combat casualties during operations Iraqi Freedom and Enduring Freedom.

BACKGROUND Continued assessment of casualty complications, such as infections, enables the development of evidence-based guidelines to mitigate excess morbidity and mortality. We examine the Joint Theater Trauma Registry (JTTR) for infections and potential risk factors, such as transfusions, among Iraq and Afghanistan trauma patients. METHODS JTTR entries from deployment-related injuries with completed records between March 19, 2003, and April 13, 2009, were evaluated using International Classification of Diseases-9 codes for infections defined by anatomic/clinical syndromes and/or type of infecting organisms. Risk factors included mechanisms of injury, patient demographics, Injury Severity Score (ISS), and transfusion, including massive transfusions (≥ 10 units of packed red blood cells). RESULTS We reviewed 16,742 patients entries (15,021 from Operation Iraqi Freedom (9,883 battle injuries [BI]) and 1,721 from Operation Enduring Freedom (1,090 BI). A total of 96.6% were men and 77.6% were Army personnel. The majority of BI were due to explosive devices (36.3%). There were 921 patients (5.5%) who had one or more infection codes with only 111 (0.6%) recorded deaths (16 with infections). Infections were commonly gram-negative bacteria (47.6%) involving skin/wound infections (26.7%), and lung infections (14.6%). Risk factors or associations that were most notable in univariate and multivariate analysis were calendar year of trauma, ISS, and pattern of injury. CONCLUSION The 5.5% infection rate is consistent with previous military and civilian trauma literature; however, with the limitations of the JTTR, the infection rate is likely an underrepresentation due to inadequate level V and long-term infectious complications data. Combat operational trauma is primarily associated with gram-negative bacteria typically involving infections of wounds or other skin structures and lung infections such as pneumonia. They are commonly linked with higher ISS and injuries to the head, neck, and face.