Battlefield Casualties Research Articles

Field triage score (FTS) in battlefield casualties: validation of a novel triage technique in a combat environment

Background By the principles of Tactical Combat Casualty Care, battlefield casualties are preferentially triaged on the basis of pulse character and mental status. A weak or absent palpable pulse correlates with a systolic blood pressure (SBP) of ≤100 mm Hg. Furthermore, the motor component of the Glasgow Coma Scale (GCS-M) has been shown to correlate with outcomes. In a previous study, the authors developed a simple triage tool, the field triage score (FTS), on the basis of pulse character and GCS-M status, which provided a quick and effective means of predicting injury survival in the civilian trauma environment. The purpose of this analysis was to validate the predictive utility of the FTS in the battlefield trauma environment. Methods The Joint Theater Trauma Registry was used to identify 4,988 battlefield casualties from Iraq and Afghanistan from January 2002 to September 2008 with requisite admission data elements of SBP, GCS-M status, and survival. SBP was stratified as ≤100 mm Hg, consistent with weak or absent pulse character, or >100 mm Hg, consistent with a normal pulse character. GCS-M status was stratified as either abnormal (<6) or normal (6). Casualties with presenting SBPs of 0 mm Hg were excluded from the analysis. As in the civilian trauma triage study, the FTS was derived by assigning a component value of 0 for weak or absent pulse or abnormal GCS-M status and a component value of 1 for either a normal pulse or normal GCS-M status. Adding the scores resulted in an aggregate FTS value of 0, 1, or 2. Results For the overall population of 4,988 casualties, 87.5% (n = 4,366) had FTS of 2, with overall mortality of .1% (5 of 4,366). From the battlefield, 10.8% of patients (n = 540) presenting with FTS of 1 had a mortality rate that increased to 6.1% (33 of 540). In contrast, combat casualties presenting with FTS of 0 had a significantly higher mortality of 41.4% (34 of 82). The calculated lengths of stay were 6.1 (FTS 2), 9.2 (FTS 1), and 17.7 (FTS 0) days. Conclusion This study has validated the utility of the FTS as a simple and practical triage instrument for use in the battlefield environment. Using the FTS, medics and medical providers will have a quick and effective measure to predict high-acuity combat casualties to triage evacuation and medical resources in austere military environments. This technique may have potential implications for domestic or foreign disaster or mass casualty situations in which supplies, medical resources, and facilities are limited.

Diversity and Clinical Impact of Acinetobacter baumannii Colonization and Infection at a Military Medical Center

The epidemiology of Acinetobacter baumannii emerging in combat casualties is poorly understood. We analyzed 65 (54 nonreplicate) Acinetobacter isolates from 48 patients (46 hospitalized and 2 outpatient trainees entering the military) from October 2004 to October 2005 for genotypic similarities, time-space relatedness, and antibiotic susceptibility. Clinical and surveillance cultures were compared by amplified fragment length polymorphism (AFLP) genomic fingerprinting to each other and to strains of a reference database. Antibiotic susceptibility was determined, and multiplex PCR was performed for OXA-23-like, -24-like, -51-like, and -58-like carbapenemases. Records were reviewed for overlapping hospital stays of the most frequent genotypes, and risk ratios were calculated for any association of genotype with severity of Acute Physiology and Chronic Health Evaluation II (APACHE II) score or injury severity score (ISS) and previous antibiotic use. Nineteen genotypes were identified; two predominated, one consistent with an emerging novel international clone and the other unique to our database. Both predominant genotypes were carbapenem resistant, were present at another hospital before patients' admission to our facility, and were associated with higher APACHE II scores, higher ISSs, and previous carbapenem antibiotics in comparison with other genotypes. One predominated in wound and respiratory isolates, and the other predominated in wound and skin surveillance samples. Several other genotypes were identified as European clones I to III. Acinetobacter genotypes from recruits upon entry to the military, unlike those in hospitalized patients, did not include carbapenem-resistant genotypes. Acinetobacter species isolated from battlefield casualties are diverse, including genotypes belonging to European clones I to III. Two carbapenem-resistant genotypes were epidemic, one of which appeared to belong to a novel international clone.

Tourniquet-induced acute ischemia–reperfusion injury in mouse skeletal muscles: Involvement of superoxide

Although arterial limb tourniquet is one of the first-line treatments to prevent exsanguinating hemorrhage in both civilian pre-hospital and battlefield casualty care, prolonged application of a limb tourniquet can lead to serious ischemia–reperfusion injury. However, the underlying pathomechanisms of tourniquet-induced ischemia–reperfusion injury are still poorly understood. Using a murine model of acute limb ischemia–reperfusion, we investigated if acute limb ischemia–reperfusion injury is mediated by superoxide overproduction and mitochondrial dysfunction. Hind limbs of C57/BL6 mice were subjected to 3 h ischemia and 4 h reperfusion via placement and release of a rubber tourniquet at the greater trochanter. Approximately 40% of the gastrocnemius muscle suffered infarction in this model. Activities of mitochondrial electron transport chain complexes including complex I, II, III, and IV in the gastrocnemius muscle were decreased in the ischemia–reperfusion group compared to sham. Superoxide production was increased while activity of manganese superoxide dismutase (MnSOD, the mitochondria-targeted SOD isoform) was decreased in the ischemia–reperfusion group compared to the sham group. Pretreatment with tempol (a SOD mimetic, 50 mg/kg) or co-enzyme Q 10 (50 mg/kg) not only decreased the superoxide production, but also reduced the infarct size and normalized mitochondrial dysfunction in the gastrocnemius muscle. Our results suggest that tourniquet-induced skeletal muscle ischemia–reperfusion injuries including infarct size and mitochondrial dysfunction may be mediated via superoxide overproduction and reduced antioxidant activity. In the future, this murine ischemia–reperfusion model can be adapted to mechanistically evaluate anti-ischemic molecules in tourniquet-induced skeletal muscle injury.

An upshot of war – Damage control resuscitation

Management of battlefield casualties in Iraq and Afghanistan has seen considerable development in damage control resuscitation, which aims to address the risk of haemorrhage, initially due to mechanical damage; and thereafter due to the development of life-threatening coagulopathy. Damage control resuscitation combines a variety of techniques, such as the use of the combat application tourniquet and novel haemostatics, through to ground-breaking developments in transfusion protocols. These practical aspects of the doctrine are combined with an ethos which sees consultant-led care implemented from as close to the point of wounding as is possible. Meticulous trauma audit is included in this process and has allowed for rapid translation of knowledge into practice. The main elements of this doctrine are described.

Battlefield Casualty: The Archaeology of a Captured Gun

Many artefacts in museums lack adequate information about the context from which they were collected. Not surprisingly, this often applies to artefacts recovered from battlefields, where chaotic conditions can result in uncertainty about their origins. This paper examines the case of a Second World War German 88 mm gun preserved in an Australian museum. The museum had little contextual information for this weapon, except that the Australian Army captured it in North Africa in 1942, probably after the Second Battle of El Alamein. However, an archaeological analysis of the gun, particularly of damage incurred during battle, can link it to photographs taken after the battle and re-establish its historical context and the circumstances of its acquisition. In this way, a museum artefact can become more than a mere exhibit: it can be made to document its own past.

Evolving Need for Alternative Triage Management in Public Health Emergencies: A Hurricane Katrina Case Study

In many countries, traditional medical planning for disasters developed largely in response to battlefield and multiple casualty incidents, generally involving corporal injuries. The mass evacuation of a metropolitan population in the aftermath of Hurricane Katrina evolved into life-and-death triage scenarios involving thousands of patients with nontraumatic illnesses and special medical needs. Although unprecedented in the United States, triage management needs for this disaster were similar to other large-scale public health emergencies, both natural and human-generated, that occurred globally in the past half-century. The need for alternative triage-management processes similar to the methodologies of other global mass public health emergencies is illustrated through the experience of disaster medical assistance teams in the first 3 days following Katrina's landfall. The immediate establishment of disaster-specific, consensus-based, public health emergency-related triage protocols-developed with ethical and legal expertise and a renewed focus on multidimensional, multifactorial matrix decision-making processes-is strongly recommended.

Settling It on the Field

Using a sample of battlefield data from twentieth-century wars, the author of this article tests a number of previously untested hypotheses linking battle events and the decision to end violent conflict. The author explores how factors like the distribution of power, battlefield casualties, and information that flows from the battlefield influence war termination. The analysis speaks to the validity of competing rational choice theories of war termination.

Trans-sodium crocetinate for treating hypoxia/ischemia

Background: Trans-sodium crocetinate (TSC) is a novel compound that offers promise as a treatment for conditions caused by hypoxia or ischemia. TSC was originally developed at the University of Virginia for hemorrhagic shock, as part of the battlefield casualty program sponsored by the US Office of Naval Research. Animal toxicology studies have demonstrated that high levels of TSC are well-tolerated, and a Phase I clinical study has shown that TSC is also safe in humans. Objective: The drug acts via a mechanism that has not been previously exploited in a pharmaceutical. TSC increases the rate of oxygen diffusion between the erythrocytes and the tissues by altering the ‘structure’ of water in blood plasma. It does this by causing additional hydrogen bonds to form among the water molecules. Conclusion: Further development of TSC for hemorrhagic shock and other hypoxic/ischemic conditions is being done by Diffusion Pharmaceuticals LLC.

Trauma-related Infections in Battlefield Casualties From Iraq

Trauma-related Infections in Battlefield Casualties From Iraq

Tourniquets: A Review of Current Use with Proposals for Expanded Prehospital Use

The use of arterial tourniquets in prehospital emergency care has been fraught with controversy andsuperstition for many years despite the potential utility of these tools. This review examines this controversy in the context of the history of the tourniquet as well as its recent use in surgery andmodern battlefield casualty care. Safe prehospital tourniquet use is widespread in the military andis based on sound physiologic data andclinical experience from the surgical use of tourniquets. The physiologic, pathophysiologic, andclinical underpinnings of safe tourniquet use are reviewed here, along with a discussion of alternatives to tourniquets. Prehospital settings in which tourniquets are useful include tactical emergency medical services (EMS) andother law enforcement environments as well as disaster andmass casualty incidents. Beyond this, we present arguments for tourniquet use in more routine EMS settings, in which it may be beneficial but has heretofore been considered inappropriate. Protocols that foster safe, effective prehospital tourniquet use in these settings are then presented. Finally, we discuss future directions in which tourniquet research andother initiatives will further enhance the safe, rational use of this potentially life-saving tool.

Use of Surgisis for Abdominal Wall Reconstruction/Closure in Battlefield Casualties during Operation Iraqi Freedom

A case series and discussion based on experiences gained during Operation Iraqi Freedom are presented. The Army previously published an article on the use of Gore-Tex mesh in the staged closure of open abdominal wounds. We thought that use of a biomaterial could shorten the overall course of abdominal closure and improve outcomes. This is mainly a "proof of concept" type of study. Although class I data are not presented, a useful concept is discussed. To our knowledge, no other report of the use of biomaterials for battle casualties has been published. Several issues that are faced by the military medical system are presented. The use of Surgisis (lyophilized porcine small intestinal submucosa; Cook Biotech, West Lafayette, Indiana) in the described setting is presented as one possible solution.

Thresholded Area Over the Curve of Spectrometric Tissue Oxygen Saturation as an Indicator of Volume Resuscitability in Porcine Hemorrhagic Shock

A rapid, reliable, and noninvasive functional measure of responsiveness to resuscitation in posttraumatic hemorrhagic shock could prove useful in guiding therapy, especially under circumstances such as the battlefield and civilian mass casualties. Tissue oxygen saturation (Sto2) is a promising candidate for this application. We therefore explored the value of peripheral muscle Sto2 in predicting systemic responsiveness to colloid volume resuscitation in a porcine model of hemorrhagic shock. Fourteen isoflurane-anesthetized piglets were subjected to a standardized hemorrhage protocol that maintained mean arterial pressure (MAP) between 30 and 40 mm Hg. Asanguineous resuscitation with a volume of Hextend equal to the total volume bled was initiated when compensation was exhausted (MAP <30 mm Hg). We recorded continuous MAP and Sto2 values, and calculated the contiguous area over the Sto2 curve yet below a given threshold of Sto2 (TAOC) as a function of this threshold before the selected timepoint for timepoints up to 30 minutes before resuscitation. Hemorrhage resulted in significant fluctuations of MAP and high interindividual variability of disease dynamics and outcome: 4 nonsurvivors and 10 survivors at 2 hours postresuscitation. Sto2 measurements reflected hemodynamic conditions in most animals, with a pronounced drop preceding final decompensation in 7 of 14 animals. TAOC discriminated three of four nonresuscitable (nonsurvivor) animals from the survivors, with group differences reaching significance even for the earliest examined timepoint (30 minutes before resuscitation), depending on the choice of TAOC threshold. Sto2 may serve as a marker of decompensation, whereas TAOC, a physiologically motivated correlate of perfusion debt and cumulative hypoperfusion injury, may be a useful early indicator of responsiveness to volume resuscitation in hemorrhagic shock.

Training Physicians for Combat Casualty Care on the Modern Battlefield

Trauma training among nonsurgical physicians in the military is highly variable in amount and quality. However, all deployed military physicians, regardless of specialty, are expected to provide combat casualty care. The goal was to assess the effectiveness of an intense modular trauma refresher course for nonsurgical physicians deploying to a combat zone. All graduating nonsurgical residents participated in this 2.5-day course, consisting of 4 modules: (1) didactic session; (2) simulation with interactive human surgical simulators; (3) case presentations and triage scenarios from Iraq/Afghanistan with associated skill stations; and (4) live tissue surgical procedure laboratory. Competency tests, surveys, and after action comments were reviewed and compared before and after course completion. Between May 2005 and April 2007, 60 physicians participated in the course. By specialties, there were 32 internists, 16 pediatricians, 7 general practitioners, 4 obstetricians/gynecologists, and 1 "other" nonsurgical physician represented. Precourse and postcourse tests were administered to 31 of 60 participants. The mean test scores improved from 76% to 96% upon completion of the course (p < 0.01). Additionally, self-perceived confidence levels in handling battlefield casualties from questionnaires based on Likert scale responses (1 = not confident, 5 = confident) improved from an average of 2.3 before the course to 3.9 upon completion of the course (p < 0.01). All military physicians must be prepared to manage combat casualties. This hybrid training model may be an effective method to prepare nonsurgeons to deal with battle injuries. This course significantly improved the knowledge and confidence among primary care physicians.

Trauma-related infections in battlefield casualties from Iraq.

To describe risks for, and microbiology and antimicrobial resistance patterns of, war trauma associated infections from Operation Iraqi Freedom. : The invasion of Iraq resulted in casualties from high-velocity gunshot, shrapnel, and blunt trauma injuries as well as burns. Infectious complications of these unique war trauma injuries have not been described since the 1970s. Retrospective record review of all trauma casualties 5 to 65 years of age evacuated from the Iraqi theatre to U.S. Navy hospital ship, USNS Comfort, March to May 2003.War trauma-associated infection was defined by positive culture from a wound or sterile body fluid (ie, blood, cerebrospinal fluid) and at least two of the following infection-associated signs/symptoms: fever, dehiscence, foul smell, peri-wound erythema, hypotension, and leukocytosis. A comparison of mechanisms of injury, demographics, and clinical variables was done using multivariate analysis. Of 211 patients, 56 met criteria for infection. Infections were more common in blast injuries, soft tissue injuries, >3 wound sites, loss of limb, abdominal trauma, and higher Injury Severity Score (ISS). Wound infections accounted for 84% of cases, followed by bloodstream infections (38%). Infected were more likely to have had fever prior to arrival, and had higher probability of ICU admission and more surgical procedures. Acinetobacter species (36%) were the predominant organisms followed by Escherichia coli and Pseudomonas species (14% each). Similar to the Vietnam War experience, gram-negative rods, particularly Acinetobacter species, accounted for the majority of wound infections cared for on USNS Comfort during Operation Iraqi Freedom. Multidrug resistance was common, with the exception of the carbapenem class, limiting antibiotic therapy options.

Recombinant Activated Factor VII Increases Survival Time in a Model of Incompressible Arterial Hemorrhage in the Anesthetized Pig

Hemorrhage is the leading cause of death in battlefield casualties and the second leading cause of death after civilian trauma. Evacuation time for military casualties to surgical care can be prolonged and improved hemostasis could greatly reduce mortality. There are several anecdotal reports that recombinant activated factor VII (rFVIIa) may arrest uncontrolled bleeding after trauma. However, the majority of prospective randomized controlled trials show little benefit in survival. The aim of this study was to determine whether rFVIIa could increase survival time within a clinically relevant time scale for military practice and reduce the volume of blood loss in a model of incompressible arterial hemorrhage. A secondary aim was to determine the effects of hypotensive versus normotensive resuscitation on the effectiveness of rFVIIa. Terminally anaesthetized Large White pigs were randomly allocated to one of four treatment groups. All animals received a controlled hemorrhage of 40% of the total estimated blood volume. They were given either rFVIIa (180 microg/kg) or placebo (saline 0.3 mL/kg) intravenously and a 4 to 5 mm longitudinal aortotomy created in the infra renal aorta before resuscitation commenced with 0.9% saline to one of two target systolic arterial blood pressures (SBPs): 110 mm Hg (normotensive) or 80 mm Hg (hypotensive). Group sizes were as follows: placebo/normotensive (6), placebo/hypotensive (7), rFVIIa/normotensive (7), and rFVIIa/hypotensive (7). Survival was monitored for a maximum of 6 hours after the onset of resuscitation. rFVIIa was associated with a significantly prolonged survival time in animals managed hypotensively (214 [79-349] vs. 35 [19-52] minutes mean [95% confidence interval] rFVIIa vs. placebo, p = 0.03 Peto log rank test). There was no significant difference in survival time between those given rFVIIa and placebo in groups managed normotensively (128 [6-249] vs. 40 [15-66] minutes respectively, p = 0.27). Both rFVIIa and hypotensive management were associated with reduced uncontrolled hemorrhage volumes. There was no evidence of inappropriate intravascular thrombi or microthrombi associated with the use of rFVIIa. rFVIIa, combined with hypotensive resuscitation, can increase survival time and reduce hemorrhage in a model of arterial hemorrhage. The increase in survival time is clinically relevant for military evacuation of battlefield casualties to surgical care.

Acute Respiratory Distress Syndrome in Combat Casualties: Military Medicine and Advances in Mechanical Ventilation

Military medicine has made numerous enduring contributions to the advancement of pulmonary medicine. Acute respiratory distress syndrome was first recognized as a complication in battlefield casualties in World War I and continued to play a significant role in the treatment of casualties through the Vietnam War. Innovative surgeons during World War II devised methods to assist their patients with positive pressure breathing. This concept was later adopted and applied to the development of mechanical ventilation in the late 1940s and early 1950s. The continued treatment of acute respiratory distress syndrome in combat casualties by military physicians has provided a major impetus for advances in modern mechanical ventilation and intensive care unit medicine.

Auscultation in high-noise environments using hybrid electromechanical and ultrasound-Doppler techniques

Medical evacuation of battlefield casualties or traffic accident victims by air typically takes place in very noisy environments. Auscultation of patients, e.g., to support chest intubation or to detect a pneumothorax, is therefore difficult or impossible to perform. A conventional acoustic stethoscope will not function very well in background noise levels beyond 80 dB. Electronic stethoscopes, in combination with mechanical impedance-matched transducer designs, can extend this range to about 90 dB, but this is not enough for helicopter noise levels that can reach 110 dB. The use of an ultrasound transmitter and receiver, however, provides an essentially noise-free auscultation channel since transportation vehicles do not produce acoustic energy at ultrasound carrier frequencies of 2–3 MHz. Clean and noise-free heart and breath sounds have been obtained in broadband noise fields of intensities as high as 120 dB. A hybrid stethoscope has been developed that allows auscultation by ultrasound-Doppler as well as electromechanical means. Pros and cons of making Doppler sounds subjectively similar to conventional sounds by nonlinear signal processing will be discussed, as well as potentially functional and meaningful aspects of Doppler signals that are not found in conventional stethoscope sounds.

Admission Physiology Criteria After Injury on the Battlefield Predict Medical Resource Utilization and Patient Mortality

Medical resources and resource allocation including operating room and blood utilization are of prime importance in the modern combat environment. We hypothesized that easily measurable admission physiologic criteria and injury site as well as injury severity calculated after diagnostic evaluation or surgical intervention, would be strongly correlated with resource utilization and in theater mortality outcomes. We retrospectively reviewed the Joint Theater Trauma Registry for all battlefield casualties presenting to surgical component facilities during Operation Iraqi Freedom from January to July 2004. Data were collected from the composite population of 1,127 battlefield casualty patients with respect to demographics, mechanism, presentation physiology (blood pressure, heart rate, temperature), base deficit, admission hematocrit, Glasgow Coma Score (GCS), Injury Severity Score (ISS), operating room utilization, blood transfusion, and mortality. Univariate and multivariate analyses were conducted to determine the degree to which admission physiology and injury severity correlated with blood utilization, necessity for operation, and acute mortality. Univariate analysis demonstrated a significant (p < 0.05) association between hypothermia (T < 34 degrees C) and the subsequent requirement for operation and mortality. In addition, the outcome variable total blood product utilization was significantly correlated with base deficit (r = 0.61), admission hematocrit (r = 0.51), temperature (r = 0.47), and ISS (r = 0.54). Using multiple logistic regression techniques, blood pressure, GCS, and ISS together demonstrated a significant association (p < 0.05) with mortality (area under ROC curve = 95%). Multiple linear regression established that blood pressure, heart rate, temperature, hematocrit, and ISS had a collective significant effect (p < 0.05) on total blood product utilization explaining 67% of the variance in this outcome variable. Admission physiology and injury characteristics demonstrate a strong capacity to predict resource utilization in the contemporary battlefield environment. In the future, such predictive yield could potentially have significant implications for triage and medical logistics in the resource constrained environment of war and potentially in mass casualty and disaster incidents in the civilian trauma setting which will likely have mechanistic similarity with war related injury.

347: United States Air Force Critical Care Air Transport Teams in Operation Iraqi Freedom: A Prospective Study

In the mid-1990’s the United States Air Force created Critical Care Air Transport Teams (CCATT) to support the new military doctrine of forward resuscitation and early evacuation of battlefield casualties. Operation Iraqi Freedom (OIF) represents the first large scale test of the CCATT concept. The feature of the CCATT that distinguishes it from civilian aeromedical teams is the ability to transport multiple unstable patients, many of whom have only received temporizing care, over long distances.

Are i-STAT Results Adversely Affected by an Artificial Blood Substitute In Vivo?

The purpose of this study was to determine whether i-STAT measurements on blood treated with hemoglobin-based oxygen carrier-201 (HBOC-201) would provide laboratory test results comparable to those achieved with a known reliable piece of equipment (Radiometer) for swine blood treated with HBOC-201. HBOC-201 is an artificial blood substitute solution being considered for use by medics in the field for the treatment of combat casualties. The i-STAT is a portable compact piece of laboratory equipment used for rapid assessment of blood samples under field conditions, instead of larger, hospital-based, laboratory equipment. Blood from pigs was obtained before and after administration of HBOC-201. The blood was tested with the i-STAT and the Radiometer. No drastic inaccuracy in test results with the i-STAT can be predicted for battlefield casualty care with potential HBOC-201 use, because laboratory results with the i-STAT and Radiometer were comparable with respect to blood testing after the administration of HBOC-201.