United States Army Institute of Surgical Research

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.

The world-wide impact of traumatic injury and associated hemorrhage on human health and well-being cannot be overstated. Twelve percent of the global disease burden is the result of violence or accidental injury. Hemorrhage is responsible for 30 to 40% of trauma mortality, and of these deaths, 33 to 56% occur during the prehospital period. Among those who reach care, early mortality is caused by continued hemorrhage, coagulopathy, and incomplete resuscitation. The techniques of early care, including blood transfusion, may underlie late mortality and long-term morbidity. While the volume of blood lost cannot be measured, physiologic and chemical measures and the number of units of blood given are readily recorded and analyzed. Improvements in early hemorrhage control and resuscitation and the prevention and aggressive treatment of coagulopathy appear to have the greatest potential to improve outcomes in severely injured trauma patients.

Rapid progress in trauma care occurs when the results of translational research are promptly integrated into clinical practice. Experience with a high volume of severely injured casualties expedites the process.1 Historically, these conditions have converged during times of conflict, improving the care of combat casualties and subsequently that of civilian trauma patients.1,2 In the most severely injured casualties, we know that when the lethal triad of hypothermia, acidosis, and coagulopathy are present, death is imminent.3 Current teaching is to avoid reaching these conditions by using “damage control surgery.”4–6 However, conventional resuscitation practice for damage control focuses on rapid reversal of acidosis and prevention of hypothermia, and surgical techniques focus on controlling hemorrhage and contamination. Direct treatment of coagulopathy has been relatively neglected, viewed as a byproduct of resuscitation, hemodilution, and hypothermia, and delayed by blood banking logistics. Damage control resuscitation addresses the entire lethal triad immediately upon admission to a combat hospital.7,8 By demonstrating that in the severely injured the coagulopathy of trauma is present at admission, recent studies have brought back to light the importance of treating this disorder at an earlier stage.9–12 Reports of lactated Ringer's solution and normal saline increasing reperfusion injury and leukocyte adhesion lead one to conclude that the standard crystalloid-based resuscitation guidelines in prehospital trauma life support (PHTLS) and advanced trauma life support (ATLS) may worsen the presenting acidosis and coagulopathy in severely injured trauma patients, and possibly increase ARDS, SIRS, and MOF.13–17 The safety of withholding PRBCs in hemodynamically stable patients has been demonstrated,18 and the risks associated with blood transfusion are well described.19,20 Further, massive transfusion in military and civilian casualties has been associated with an increased risk of death.21–23 Taken together, these observations suggest that the most severely injured may need a resuscitative approach tailored specifically to their needs. However, even in the largest civilian academic trauma centers, patients with injuries at the outer limits of survivability, such as those massively transfused with more than 10 units of RBCs in the first 24 hours, are uncommon and constitute only 1% to 2% of the patient population, making it difficult to develop and test new resuscitation concepts.21 Because 7% of combat casualties require massive transfusion, we have had just such an opportunity to observe the effects of new resuscitation strategies in the combat hospitals of Iraq and Afghanistan. The military munitions used in Southwest Asia can inflict severe multisystem injuries on both combatants and civilians. These patients frequently present to American military medical personnel shortly after being wounded. Unlike civilian systems, where treatment of coagulopathy is often limited by standard blood bank logistics, in Iraq we frequently have immediate access to PRBCs and thawed AB or A plasma, and rapid access to apheresis platelets, prepooled cryoprecipitate, fresh whole blood, and rFVIIa, as indicated.24–29 Thus, the opportunity to formally evaluate the immediate and direct treatment of the coagulopathy of trauma is available. The trauma patients who are most severely injured (approximately 10%) also represent the majority of in-hospital trauma deaths. Considerable attention has been directed toward the technical details of damage control surgery and reversing the acidosis and hypothermia present at admission. Less attention has been directed toward reversing the coagulopathy related to blood loss that is present at the same time. Clinical experience in Operation Iraqi Freedom and Operation Enduring Freedom suggests that coagulopathy may be present at the time of admission before significant resuscitative fluid has been given, as a consequence of acidosis-induced coagulation factor dysfunction, coagulation factor consumption, and hypothermia-induced failure of platelet activation. Failure to recognize and immediately address the coagulopathy found in severely injured patients can be linked to several factors. Most studies of trauma-induced coagulopathy have measured the laboratory changes that happen in the OR or ICU after dilution with crystalloid and PRBCs, and have concluded that the coagulopathy could be fully explained by the resuscitation and/or hypothermia.30 The goal of shock resuscitation efforts in the past has been largely to support blood pressure and urine output and to reverse the metabolic derangements associated with the ischemia associated with acute blood loss.31,32 Although these goals are obviously important, the studies supporting this concept were based on controlled animal hemorrhage studies, and the results were not evaluated in randomized human trials.33–35 Additionally, the potential benefits of mitigating ischemia-induced reperfusion injury after standard crystalloid resuscitation were not fully recognized.14,36 Furthermore, recent resuscitation studies have overlooked the importance of an integrated and coherent prehospital, ED, OR, and ICU shock resuscitation plan that incorporates intravascular treatment of coagulopathy.32,37 Finally, the current generation of clinicians has been taught to not use plasma as a resuscitation fluid.38 We agree that current standard resuscitation methods are appropriate policy for the approximately 90% of trauma patients who are not in shock and are hypercoagulable after injury.39–42 However, for the approximately 10% of casualties who constitute the most seriously injured, are in shock and coagulopathic, and represent the potentially preventable hemorrhagic deaths, liquid plasma may be the optimal resuscitation fluid currently available.43–50 Based on (1) previous civilian clinical studies, (2) the recommendations of an international consensus conference on early massive transfusion for trauma,51 and (3) considerable experience in the current war, we think patients at high risk for coagulopathy can be readily identified at admission and prompt simultaneous treatment of hypothermia, acidosis, and coagulopathy initiated. Hypothermia, an independent factor for increased mortality in trauma patients, was an earlier focus for active prevention and treatment,52–54 but application of training and equipment recommendations of the Committee on Tactical Combat Casualty Care and the Joint Theater Trauma System has made it an uncommon finding.55 Acidosis significantly impairs the thrombin generation rates, critical to optimal coagulation function56 and is thus aggressively managed by use of THAM and volume loading with blood components once hemostasis is obtained, with restoration of a normal blood lactate, base deficit, or pH as the ultimate goal. Damage control resuscitation as a structured intervention begins immediately after rapid initial assessment in the ED and progresses through the OR into the ICU. All efforts are directed toward this goal by repeated point of care testing and the use of multiple blood products and drugs readily available in theater, albeit in new ratios and amounts. Compared with civilian practice, damage control resuscitation efforts are largely completed in the OR, with little resuscitation required in the ICU. Achieving this goal quickly in the OR may allow a shift from limited damage control surgery to earlier definitive surgical interventions, including sophisticated limb salvage techniques, and improved outcomes. In the severely injured casualty, damage control resuscitation consists of two parts and is initiated within minutes of arrival in the ED. First, resuscitation is limited to keep blood pressure at approximately 90 mm Hg, preventing renewed bleeding from recently clotted vessels.15,17,39,57–62 Second, intravascular volume restoration is accomplished by using thawed plasma as a primary resuscitation fluid in at least a 1:1 or 1:2 ratio with PRBCs.8,10,48–50 Our initial clinical experience shows these ratios decrease mortality in similarly injured casualties (Borgman MA, et al. unpublished data). Recombinant FVIIa is occasionally used along with the early units of red cells and as required throughout the resuscitation. For casualties who will require continued resuscitation, the blood bank is notified to activate the massive transfusion protocol and deliver to the operating room 6 units of plasma, 6 units of PRBCs, 6 packs of platelets, and 10 units of cryoprecipitate stored in individual coolers.50 The most severely injured of this group also receive fresh warm whole blood as a resuscitative fluid.47,63 Additional coolers, containing the same mix of blood products, are provided as needed until the massive transfusion order is cancelled. Crystalloid use is minimized and serves mainly as a drug carrier and to keep lines open between the units of blood products. In combat casualties requiring major resuscitation (10–40 units of blood products), we have found as little as 5 L to 8 L of crystalloid are utilized during the first 24 hours, representing a decrease of at least 50% when compared with current standard resuscitation practices. Using the damage control resuscitation approach, the lack of intraoperative coagulopathic bleeding has been remarkable, allowing surgeons to focus on surgical bleeding. Patients treated in this fashion almost always arrive in the ICU warm, euvolemic, and non-acidotic, with a normal INR and minimal edema. In the majority of patients the abnormalities of the lethal triad are absent. These patients appear to be easily ventilated and more quickly extubated than patients with similar blood loss treated with the standard crystalloid resuscitation volumes and blood component ratios. These admittedly anecdotal yet compelling observations cause us to question further the use of excessive crystalloid resuscitation and to begin to formulate hypotheses that can be tested to demonstrate beneficial effects of pre-emptive control of coagulopathy.14 For the first time in US warfare, data for all admitted trauma casualties in the current conflict in Southwest Asia are entered into a joint theater trauma registry (JTTR).64 A deployed combat research team is being sent into theater for the first time since Vietnam, operating under the same standards of IRB approval as practiced in the United States. Data collected by this team, along with outcome data from the JTTR, will allow an analysis of the effects of resuscitation with thawed plasma, fresh whole blood, administration of rFVIIa, and limited crystalloid. Additionally, focused effort will be required to describe the mechanisms causing the early coagulopathy of trauma present at admission. The clinical effects and consequences of damage control resuscitation will be measurable in patient outcomes. We will know if we are saving more severely injured soldiers, if reducing coagulopathy and edema leads to better outcomes, and, ultimately, whether we are creating more blood exposure or less. We will soon have sufficient data to assess the full benefits of damage control resuscitation in the population of critically injured for whom it matters most. As in the past, perceptive observation, thoughtful discussion, and insightful analysis concerning medical care during war from experienced military medics, surgeons, and scientists, in concert with our civilian colleagues, will generate recommendations for new and improved medical practice, with continuous modification as further experience, research, and development produce new and relevant information.1,2

OBJECTIVE: To determine the effect of blood component ratios in massive transfusion (MT), we hypothesized that increased use of plasma and platelet to red blood cell (RBC) ratios would result in decreased early hemorrhagic death and this benefit would be sustained over the ensuing hospitalization. SUMMARY BACKGROUND DATA: Civilian guidelines for massive transfusion (MT > or =10 units of RBC in 24 hours) have typically recommend a 1:3 ratio of plasma:RBC, whereas optimal platelet:RBC ratios are unknown. Conversely, military data shows that a plasma:RBC ratio approaching 1:1 improves long term outcomes in MT combat casualties. There is little consensus on optimal platelet transfusions in either civilian or military practice. At present, the optimal combinations of plasma, platelet, and RBCs for MT in civilian patients is unclear. METHODS: Records of 467 MT trauma patients transported from the scene to 16 level 1 trauma centers between July 2005 and June 2006 were reviewed. One patient who died within 30 minutes of admission was excluded. Based on high and low plasma and platelet to RBC ratios, 4 groups were analyzed. RESULTS: Among 466 MT patients, survival varied by center from 41% to 74%. Mean injury severity score varied by center from 22 to 40; the average of the center means was 33. The plasma:RBC ratio ranged from 0 to 2.89 (mean +/- SD: 0.56 +/- 0.35) and the platelets:RBC ratio ranged from 0 to 2.5 (0.55 +/- 0.50). Plasma and platelet to RBC ratios and injury severity score were predictors of death at 6 hours, 24 hours, and 30 days in multivariate logistic models. Thirty-day survival was increased in patients with high plasma:RBC ratio (> or =1:2) relative to those with low plasma:RBC ratio (<1:2) (low: 40.4% vs. high: 59.6%, P < 0.01). Similarly, 30-day survival was increased in patients with high platelet:RBC ratio (> or =1:2) relative to those with low platelet:RBC ratio (<1:2) (low: 40.1% vs. high: 59.9%, P < 0.01). The combination of high plasma and high platelet to RBC ratios were associated with decreased truncal hemorrhage, increased 6-hour, 24-hour, and 30-day survival, and increased intensive care unit, ventilator, and hospital-free days (P < 0.05), with no change in multiple organ failure deaths. Statistical modeling indicated that a clinical guideline with mean plasma:RBC ratio equal to 1:1 would encompass 98% of patients within the optimal 1:2 ratio. CONCLUSIONS: Current transfusion practices and survival rates of MT patients vary widely among trauma centers. Conventional MT guidelines may underestimate the optimal plasma and platelet to RBC ratios. Survival in civilian MT patients is associated with increased plasma and platelet ratios. Massive transfusion practice guidelines should aim for a 1:1:1 ratio of plasma:platelets:RBCs.

BACKGROUND: There have been no large cohort reports detailing the wounding patterns and mechanisms in the current conflicts in Iraq and Afghanistan. METHODS: The Joint Theater Trauma Registry was queried for all US service members receiving treatment for wounds (International Classification of Diseases-9th Rev. codes 800-960) sustained in Operation Iraqi Freedom and Operation Enduring Freedom from October 2001 through January 2005. Returned-to-duty and nonbattle injuries were excluded from final analysis. RESULTS: This query resulted in 3,102 casualties, of which 31% were classified as nonbattle injuries and 18% were returned-to-duty within 72 hours. A total of 1,566 combatants sustained 6,609 combat wounds. The locations of these wounds were as follows: head (8%), eyes (6%), ears (3%), face (10%), neck (3%), thorax (6%), abdomen (11%), and extremity (54%). The proportion of head and neck wounds is higher (p < 0.0001) than the proportion experienced in World War II, Korea, and Vietnam wars (16%-21%). The proportion of thoracic wounds is a decrease (p < 0.0001) from World War II and Vietnam (13%). The proportion of gunshot wounds was 18%, whereas the proportion sustained from explosions was 78%. CONCLUSIONS: The wounding patterns currently seen in Iraq and Afghanistan resemble the patterns from previous conflicts, with some notable exceptions: a greater proportion of head and neck wounds, and a lower proportion of thoracic wounds. An explosive mechanism accounted for 78% of injuries, which is the highest proportion seen in any large-scale conflict.

Burns are a prevalent and burdensome critical care problem. The priorities of specialized facilities focus on stabilizing the patient, preventing infection, and optimizing functional recovery. Research on burns has generated sustained interest over the past few decades, and several important advancements have resulted in more effective patient stabilization and decreased mortality, especially among young patients and those with burns of intermediate extent. However, for the intensivist, challenges often exist that complicate patient support and stabilization. Furthermore, burn wounds are complex and can present unique difficulties that require late intervention or life-long rehabilitation. In addition to improvements in patient stabilization and care, research in burn wound care has yielded advancements that will continue to improve functional recovery. This article reviews recent advancements in the care of burn patients with a focus on the pathophysiology and treatment of burn wounds.

OBJECTIVES: To characterize contemporary use of tranexamic acid (TXA) in combat injury and to assess the effect of its administration on total blood product use, thromboembolic complications, and mortality. DESIGN: Retrospective observational study comparing TXA administration with no TXA in patients receiving at least 1 unit of packed red blood cells. A subgroup of patients receiving massive transfusion (≥10 units of packed red blood cells) was also examined. Univariate and multivariate regression analyses were used to identify parameters associated with survival. Kaplan-Meier life tables were used to report survival. SETTING: A Role 3 Echelon surgical hospital in southern Afghanistan. PATIENTS: A total of 896 consecutive admissions with combat injury, of which 293 received TXA, were identified from prospectively collected UK and US trauma registries. MAIN OUTCOME MEASURES: Mortality at 24 hours, 48 hours, and 30 days as well as the influence of TXA administration on postoperative coagulopathy and the rate of thromboembolic complications. RESULTS: The TXA group had lower unadjusted mortality than the no-TXA group (17.4% vs 23.9%, respectively; P = .03) despite being more severely injured (mean [SD] Injury Severity Score, 25.2 [16.6] vs 22.5 [18.5], respectively; P < .001). This benefit was greatest in the group of patients who received massive transfusion (14.4% vs 28.1%, respectively; P = .004), where TXA was also independently associated with survival (odds ratio = 7.228; 95% CI, 3.016-17.322) and less coagulopathy (P = .003). CONCLUSIONS: The use of TXA with blood component-based resuscitation following combat injury results in improved measures of coagulopathy and survival, a benefit that is most prominent in patients requiring massive transfusion. Treatment with TXA should be implemented into clinical practice as part of a resuscitation strategy following severe wartime injury and hemorrhage.

Hypermetabolism characterizes the metabolic response to thermal injury and the extent of energy production is positively related to the rate of urinary catecholamine excretion. Alpha and beta adrenergic blockade decreased metabolism from 69.6 +/- 5.3 Kcal/m(2)/hr to 57.4 +/- 5.2 (p < 0.01), and infusion of 6 microgm epinephrine/minute in normal man significantly increased metabolic rate. Twenty noninfected burned adults with a mean burn size of 45% total body surface (range 7-84%) and four normal controls were studied in an environmental chamber at two or more temperatures between 19 and 33 C with vapor pressure constant at 11.88 mm Hg. All burn patients were hypermetabolic at all temperatures studied and their core and mean skin temperatures were significantly elevated above control values. Between 25 and 33 C ambient, metabolism was unchanged in controls and burns of less than 40% total body surface (48.9 +/- 4.6 Kcal/m(2)/hr vs. 48.9 +/- 4.5), but metabolic rate decreased in larger burns in the warmer environment (72.0 +/- 1.9 vs. 65.8 +/- 1.7, p < 0.001). At 21 C, metabolism and catecholamines increased, except in four nonsurvivors who became hypothermic with decreased catechol elaboration. Metabolic rate in ten patients with bacteremia was below predicted levels while catecholamines were markedly elevated suggesting interference with tissue uptake of the neurohormonal transmitters. Feeding burn patients or administering glucose and insulin improved nitrogen retention and altered substrate flow but did not significantly reduce urinary catecholamines or metabolic rate. Burned patients are internally warm, not externally cold, and catecholamines appear to mediate their increased heat production. Hypermetabolism may be modified by ambient temperature, infection, and pharmacologic means. Alterations in hypothalamic function due to injury, resulting in increased catecholamine elaboration, would explain the metabolic response to thermal injury.

In Brief Background: Effective combat trauma management strategies depend upon an understanding of the epidemiology of death on the battlefield. Methods: A panel of military medical experts reviewed photographs and autopsy and treatment records for all Special Operations Forces (SOF) who died between October 2001 and November 2004 (n = 82). Fatal wounds were classified as nonsurvivable or potentially survivable. Training and equipment available at the time of injury were taken into consideration. A structured analysis was conducted to identify equipment, training, or research requirements for improved future outcomes. Results: Five (6%) of 82 casualties had died in an aircraft crash, and their bodies were lost at sea; autopsies had been performed on all other 77 soldiers. Nineteen deaths, including the deaths at sea were noncombat; all others were combat related. Deaths were caused by explosions (43%), gunshot wounds (28%), aircraft accidents (23%), and blunt trauma (6%). Seventy of 82 deaths (85%) were classified as nonsurvivable; 12 deaths (15%) were classified as potentially survivable. Of those with potentially survivable injuries, 16 causes of death were identified: 8 (50%) truncal hemorrhage, 3 (19%) compressible hemorrhage, 2 (13%) hemorrhage amenable to tourniquet, and 1 (6%) each from tension pneumothorax, airway obstruction, and sepsis. The population with nonsurvivable injuries was more severely injured than the population with potentially survivable injuries. Structured analysis identified improved methods of truncal hemorrhage control as a principal research requirement. Conclusions: The majority of deaths on the modern battlefield are nonsurvivable. Improved methods of intravenous or intracavitary, noncompressible hemostasis combined with rapid evacuation to surgery may increase survival. Effective combat trauma management strategies depend on an understanding of the epidemiology of death on the battlefield. A review of photographs and autopsy and treatment records of 82 combat deaths classified the majority as nonsurvivable. Twelve (15%) deaths identified as potentially survivable led us to conclude that improved methods of intravenous or intracavitary, noncompressible hemostasis, and rapid evacuation may increase survival.

In order to assess the specific effects of inhalation injury and pneumonia on mortality in burn patients, the records of 1058 patients treated at a single institution over a five-year period, 1980-1984, were reviewed. Of these patients, 373 (35%) had inhalation injury diagnosed by bronchoscopy and/or ventilation perfusion lung scan. Of the 373 patients, 141 (38%) had subsequent pneumonia. Among the patients without inhalation injury, pneumonia occurred in 60 of 685 (8.8%). A multiple logistic equation was developed to estimate expected mortality at any age and burn size for patients without either inhalation injury or pneumonia, with either alone, or with both. Subtraction of the expected mortality without either inhalation injury or pneumonia from the expected mortality in the presence of either or both permitted the estimation of additional mortality attributable to these complications. Inhalation injury alone increased mortality by a maximum of 20% and pneumonia by a maximum of 40%, with a maximum increase of approximately 60% when both were present. The influence on mortality was maximal in the midrange of expected mortality without these complications for any age group. These data indicate that inhalation injury and pneumonia have significant, independent, additive effects on burn mortality and that these effects vary with age and burn size in a predictable manner.

BACKGROUND: The opinion that injuries sustained in Iraq and Afghanistan have increased in severity is widely held by clinicians who have deployed multiple times. To continuously improve combat casualty care, the Department of Defense has enacted numerous evidence-based policies and clinical practice guidelines. We hypothesized that the severity of wounds has increased over time. Furthermore, we examined cause of death looking for opportunities of improvement for research and training. METHODS: Autopsies of the earliest combat deaths from Iraq and Afghanistan and the latest deaths of 2006 were analyzed to assess changes in injury severity and causes of death. Fatalities were classified as nonsurvivable (NS) or potentially survivable (PS). PS deaths were then reviewed in depth to analyze mechanism and cause. RESULTS: There were 486 cases from March 2003 to April 2004 (group 1) and 496 from June 2006 to December 2006 (group 2) that met inclusion criteria. Of the PS fatalities (group 1: 93 and group 2: 139), the injury severity score was lower in the first group (27 +/- 14 vs. 37 +/- 16, p < 0.001), and had a lower number of abbreviated injury scores >or=4 (1.1 +/- 0.79 vs. 1.5 +/- 0.83 per person, p < 0.001). The main cause of death in the PS fatalities was truncal hemorrhage (51% vs. 49%, p = NS). Deaths per month between groups doubled (35 vs. 71), whereas the case fatality rates between the two time periods were equivalent (11.0 vs. 9.8, p = NS). DISCUSSION: In the time periods of the war studied, deaths per month has doubled, with increases in both injury severity and number of wounds per casualty. Truncal hemorrhage is the leading cause of potentially survivable deaths. Arguably, the success of the medical improvements during this war has served to maintain the lowest case fatality rate on record.

OBJECTIVE: The purpose of this study was to determine if emergency tourniquet use saved lives. SUMMARY BACKGROUND DATA: Tourniquets have been proposed as lifesaving devices in the current war and are now issued to all soldiers. Few studies, however, describe their actual use in combat casualties. METHODS: A prospective survey of injured who required tourniquets was performed over 7 months in 2006 (NCT00517166 at ClinicalTrials.gov). Follow-up averaged 28 days. The study was at a combat support hospital in Baghdad. Among 2,838 injured and admitted civilian and military casualties with major limb trauma, 232 (8%) had 428 tourniquets applied on 309 injured limbs. We looked at emergency tourniquet use, and casualties were evaluated for shock (weak or absent radial pulse) and prehospital versus emergency department (ED) tourniquet use. We also looked at those casualties indicated for tourniquets but had none used. We assessed survival rates and limb outcome. RESULTS: There were 31 deaths (13%). Tourniquet use when shock was absent was strongly associated with survival (90% vs. 10%; P < 0.001). Prehospital tourniquets were applied in 194 patients of which 22 died (11% mortality), whereas 38 patients had ED application of which 9 died (24% mortality; P = 0.05). The 5 casualties indicated for tourniquets but had none used had a survival rate of 0% versus 87% for those casualties with tourniquets used (P < 0.001). Four patients (1.7%) sustained transient nerve palsy at the level of the tourniquet. No amputations resulted solely from tourniquet use. CONCLUSIONS: Tourniquet use when shock was absent was strongly associated with saved lives, and prehospital use was also strongly associated with lifesaving. No limbs were lost due to tourniquet use. Education and fielding of prehospital tourniquets in the military environment should continue.

BACKGROUND: Hemorrhage remains a leading cause of death in both civilian and military trauma patients. The HemCon chitosan-based hemostatic dressing is approved by the US Food and Drug Administration (FDA) for hemorrhage control. Animal data have shown the HemCon dressing to reduce hemorrhage and improve survival. The purpose of this article is to report preliminary results of the hemostatic efficacy of the HemCon dressing used in the prehospital setting on combat casualties. METHODS: A request for case information on use of HemCon dressings in Operation Iraqi Freedom and Operation Enduring Freedom was sent to deployed Special Forces combat medics, physicians, and physician assistants. RESULTS: Sixty-eight uses of the HemCon dressing were reported and reviewed by two US Army physicians. Four of the 68 cases were determined duplicative resulting in a total of 64 combat uses. Dressings were utilized externally on the chest, groin, buttock, and abdomen in 25 cases; on extremities in 35 cases; and on neck or facial wounds in 4 cases. In 66% of cases, dressings were utilized following gauze failure and were 100% successful. In 62 (97%) of the cases, the use of the HemCon dressing resulted in cessation of bleeding or improvement in hemostasis. There were two reported dressing failures that occurred with blind application of bandages up into large cavitational injuries. Dressings were reported to be most useful on areas where tourniquets could not be applied to control bleeding. The dressings were reported to be most difficult to use in extremity injuries where they could not be placed easily onto or into the wounds. No complications or adverse events were reported. CONCLUSION: This report on the field use of the HemCon dressing by medics suggests that it is a useful hemostatic dressing for prehospital combat casualties and supports further study to confirm efficacy.

The Journal of Trauma: Injury, Infection, and Critical Care: November 1968 - Volume 8 - Issue 6 - p 1049-1051

BACKGROUND: Increased understanding of the pathophysiology of the acute coagulopathy of trauma has lead many to question the current transfusion approach to hemorrhagic shock. We hypothesized that warm fresh whole blood (WFWB) transfusion would be associated with improved survival in patients with trauma compared with those transfused only stored component therapy (CT). METHODS: We retrospectively studied US Military combat casualty patients transfused >or=1 unit of red blood cells (RBCs). The following two groups of patients were compared: (1) WFWB, who were transfused WFWB, RBCs, and plasma but not apheresis platelets and (2) CT, who were transfused RBC, plasma, and apheresis platelets but not WFWB. The primary outcomes were 24-hour and 30-day survival. RESULTS: Of 354 patients analyzed there were 100 in the WFWB and 254 in the CT group. Patients in both groups had similar severity of injury determined by admission eye, verbal, and motor Glasgow Coma Score, base deficit, international normalized ratio, hemoglobin, systolic blood pressure, and injury severity score. Both 24-hour and 30-day survival were higher in the WFWB cohort compared with CT patients, 96 of 100 (96%) versus 223 of 254 (88%), (p = 0.018) and 95% to 82%, (p = 0.002), respectively. An increased amount (825 mL) of additives and anticoagulants were administered to the CT compared with the WFWB group, (p < 0.001). Upon multivariate logistic regression the use of WFWB and the volume of WFWB transfused was independently associated with improved 30-day survival. CONCLUSIONS: In patients with trauma with hemorrhagic shock, resuscitation strategies that include WFWB may improve 30-day survival, and may be a result of less anticoagulants and additives with WFWB use in this population.

OBJECTIVES: Extremity wounds and fractures traditionally comprise the majority of traumatic injuries in US armed conflicts. Little has been published regarding the extremity wounding patterns and fracture distribution in the current conflicts in Iraq and Afghanistan. The intent of this study was to describe the distribution of extremity fractures during this current conflict. DESIGN: Descriptive epidemiologic study. METHODS: The Joint Theater Trauma Registry was queried for all US service members receiving treatment for wounds (ICD-9 codes 800-960) sustained in Operation Iraqi Freedom (OIF) and Operation Enduring Freedom (OEF) from October 2001 through January 2005. Returned-to-duty and nonbattle injuries were excluded. Wounds were classified according to region and type. Extremity wounds were analyzed in detail and compared to published results from previous conflicts. RESULTS: A total of 1281 soldiers sustained 3575 extremity combat wounds. Fifty-three percent of these were penetrating soft-tissue wounds and 26% were fractures. Of the 915 fractures, 758 (82%) were open fractures. The 915 fractures were evenly distributed between the upper (461, 50%) and lower extremities (454, 50%). The most common fracture in the upper extremity was in the hand (36%) and in the lower extremity was the tibia and fibula (48%). Explosive munitions accounted for 75% of the mechanisms of injury. CONCLUSIONS: The burden of wounds sustained in OIF/OEF is extremity injuries, specifically soft-tissue wounds and fractures. These results are similar to the reported casualties from previous wars.

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 burn wound represents a susceptible site for opportunistic colonization by organisms of endogenous and exogenous origin. Patient factors such as age, extent of injury, and depth of burn in combination with microbial factors such as type and number of organisms, enzyme and toxin production, and motility determine the likelihood of invasive burn wound infection. Burn wound infections can be classified on the basis of the causative organism, the depth of invasion, and the tissue response. Diagnostic procedures and therapy must be based on an understanding of the pathophysiology of the burn wound and the pathogenesis of the various forms of burn wound infection. The time-related changes in the predominant flora of the burn wound from gram-positive to gram-negative recapitulate the history of burn wound infection. Proper clinical and culture surveillance of the burn wound permits early diagnosis of gram-positive cellulitis, and the stable susceptibility of beta-hemolytic streptococci to penicillin has eliminated the threat of this once common burn wound pathogen. Selection and dissemination of intrinsic and acquired resistance mechanisms increase the probability of burn wound colonization by resistant species such as Pseudomonas aeruginosa. Even so, effective topical antimicrobial chemotherapy and early burn wound excision have significantly reduced the overall occurrence of invasive burn wound infections. Individual patients, usually those with extensive burns in whom wound closure is difficult to achieve, may still develop a variety of bacterial and nonbacterial burn wound infections. Consequently, the entirety of the burn wound must be examined on a daily basis by the attending surgeon. Any change in wound appearance, with or without associated clinical changes, should be evaluated by biopsy. Quantitative cultures of the biopsy sample may identify predominant organisms but are not useful for making the diagnosis of invasive burn wound infection. Histologic examination of the biopsy specimen, which permits staging the invasive process, is the only reliable means of differentiating wound colonization from invasive infection. Identification of the histologic changes characteristic of bacterial, fungal, and viral infections facilitates the selection of appropriate therapy. A diagnosis of invasive burn wound infection necessitates change of both local and systemic therapy and, in the case of bacterial and fungal infections, prompt surgical removal of the infected tissue. Even after the wounds of extensively burned patients have healed or been grafted, burn wound impetigo, commonly caused by Staphylococcus aureus, may occur in the form of multifocal, small superficial abscesses that require surgical debridement. Current techniques of burn wound care have significantly reduced the incidence of invasive burn wound infection, altered the organisms causing the infections that do occur, increased the interval between injury and the onset of infection, reduced the mortality associated with infection, decreased the overall incidence of infection in burn patients, and increased burn patient survival.

From the US Army Institute of Surgical Research (A.S., T.E.R.), Fort Sam Houston, San Antonio, Texas; Academic Department of Military Surgery and Trauma (A.S.), Royal Centre for Defense Medicine, Birmingham, United Kingdom; Section of Vascular Surgery (J.L.E.), Department of Surgery, University of Michigan Health System, Ann Arbor, Michigan; and The Norman M. Rich Department of Surgery (T.E.R.), F. Edward Hebert School of Medicine, The Uniformed Services University of the Health Sciences, Bethesda, Maryland. Submitted for publication: October 31, 2011. Accepted for publication: November 1, 2011. The viewpoints expressed in this manuscript are those of the authors and do not reflect the official position of the United States Air Force or Department of Defense. Address for reprints: Todd E. Rasmussen, MD, FACS, US Army Institute of Surgical Research, 3400 Rawley E. Chambers/Suite B, Fort Sam Houston, TX 78236; email: [email protected].

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.