Prehospital blood transfusion in the en route management of severe combat trauma: a matched cohort study.

BACKGROUND: The value of prehospital blood transfusion (PHBTx) in the management of severe trauma has not been established. This study aimed to evaluate the effect of PHBTx on mortality in combat casualties. METHODS: This is a retrospective cohort study of casualties admitted to the field hospital at Camp Bastion, Afghanistan, by the Medical Emergency Response Team from May 2006 to March 2011. Participants were divided into two consecutive cohorts by the introduction of PHBTx. Paired groups of patients were chosen by combining propensity score methodology with detailed matching of injury profile. Thus recipients of PHBTx were matched with nonrecipients who would have received it had it been available. RESULTS: A total of 1,592 patients were identified. Of the 1,153 patients to whom PHBTx was potentially available, 310 received it (26.9%). The rate of severe injury (Injury Severity Score [ISS] > 15) rose from 28% before PHBTx was available to 43% thereafter (p < 0.001). Mortality in the latter group was higher (14% vs. 10%, p = 0.013) but not in the severely injured patients (32% vs. 28%, p = 0.343). Ninety-seven patients were paired. The mortality of matched patients who received PHBTx, compared with those with similar injury patterns who did not, was less than half (8.2% vs. 19.6%, p < 0.001). However, matched recipients had more prehospital interventions, reached hospital more quickly, and had lower heart rate at admission (all p < 0.05). Matched recipients received more red blood cells within 24 hours (median, 4 U; interquartile range [IQR], 2-10 U) than nonrecipients (median 0 U; IQR, 0-3.5 U) and more fresh frozen plasma (median, 2 U; IQR, 2-9 U vs. median, 0 U; IQR, 0-1 U) (both p < 0.001). CONCLUSION: An aggressive approach to damage control resuscitation including the use of PHBTx was associated with a large improvement in mortality. However, because of confounders resulting from changes in practice, the isolated contribution of PHBTx cannot be determined from this study. LEVEL OF EVIDENCE: Therapeutic study, level IV.

Demographic and geographical characteristics of pediatric trauma in Scotland.

BACKGROUND: Trauma systems reduce mortality and improve functional outcomes. The aim of this study was to analyse the demographic and geospatial characteristics of pediatric trauma patients in Scotland, and determine the level of destination healthcare facility which injured children are taken to, to determine the need for, and general feasibility, of developing a pediatric trauma system for Scotland. METHODS: Retrospective analysis of incidents involving children aged 1-14 attended to by the Scottish Ambulance Service between 1 November 2008 and 31 October 2010. A subgroup with physiological derangement was defined. Incident location postcode was used to determine incident location by health board region, rurality and social deprivation. Destination healthcare facility was classified into one of six categories. RESULTS: Of 10,759 incidents, 72.3% occurred in urban areas and 5.8% in remote areas. Incident location was associated with socioeconomic deprivation. Of the patients, 11.6% were taken to a pediatric hospital with pediatric intensive care facilities, 21.8% to a pediatric hospital without pediatric intensive care service, and 50.2% to an adult large general hospital without pediatric surgical service. CONCLUSIONS: The majority of incidents involving children with injuries occurred in urban areas. Half were taken to a hospital without pediatric surgical service. There was no difference between children with normal and deranged physiology.

Performance improvement evaluation of forward aeromedical evacuation platforms in Operation Enduring Freedom.

BACKGROUND: The following three helicopter-based medical evacuation platforms operate in Southern Afghanistan: the US Army emergency medical technician (basic)-led DUSTOFF, US Air Force paramedic-led PEDRO, and UK physician-led medical emergency response team (MERT). Nearly 90% of battlefield deaths occur in the prehospital phase, comparative outcomes for these en route care platforms are unknown. The objective of this investigation was to characterize the nature of injuries in patients transported by three evacuation platforms. In addition, it aimed to compare observed versus predicted mortality among these provider groups. METHODS: A performance improvement study involving 975 coalition patients injured in Southern Afghanistan, transported from the point of injury to a military hospital, was performed. All patients were alive on admission with prehospital documentation recorded in the US Department of Defense Trauma Registry from June 2009 to June 2011. The main outcome measure was in-hospital mortality and observed versus predicted (Trauma and Injury Severity Score [TRISS]) survival were the primary end points. RESULTS: MERT transported more amputation and polytrauma casualties and included patients with higher mean Injury Severity Score (ISS) compared with PEDRO and DUSTOFF (16 [13] vs. 11 [10] and 10 [10] respectively; p < 0.001). DUSTOFF was excluded from the subgroup analysis owing to insufficient numbers of severely injured casualties with only one death. The overall mortality for MERT and PEDRO was similar (4.2% vs. 4.6%, p = 0.967). Stratifying by ISS, there was lower mortality in MERT compared with PEDRO in the range of 20 to 29 (4.8% vs. 16.2%, p = 0.021). The observed mortality among PEDRO casualties was as predicted with the exception of the range of 20 to 29, while mortality in MERT was lower than predicted for all ISS groups with greater than 10. CONCLUSION: MERT achieves greater than predicted survival, which may be related to the additional capabilities onboard. This supports the adoption of a versatile medical evacuation system with scalable crew and equipment configurations that adapt to meet the medical, tactical, and operational needs of future conflicts.

MEDEVAC: survival and physiological parameters improved with higher level of flight medic training.

OBJECTIVE: Determine if a higher level of Army flight medic (AFM) training was associated with improved physiological state on arrival to a combat support hospital (CSH). METHODS: A retrospective study comparing casualties who were evacuated by two AFM units with only Emergency Medical Technicians-Basic (EMT-Bs) to an Army National Guard unit with Critical Care Flight Paramedics (CCFPs) in Afghanistan with an injury severity score >16 in different time periods looking at their 48-hour mortality, hematocrit (HCT), base deficit (BD), oxygen saturation (SpO2), and physiological parameters on arrival to the CSH. RESULTS: The CCFP group had better HCT [36.5 (8.8)] than the EMT-B group [33.1 (11.4); p ≤ 0.001]. BD and SpO2 were better in the CCFP group [-3.2 (4.7)]/[97.8 (4.8)] than the EMT-B group [-4.4 (5.5)]/[96.3 (10.9)] [p ≤ 0.014]. The CCFP group had a 72% lower estimated risk ratio of mortality with an associated improvement in 48-hour survivability of 4.9% versus 15.8% for the EMT-B-group. CONCLUSIONS: There is a statistically significant improvement in the HCT, BD, SpO2, and 48-hour survivability at the CSH in the cohort transported by the CCFP group when compared to the cohort transported by the EMT-B group.

Improvements in the hemodynamic stability of combat casualties during en route care.

Three Forward Aeromedical Evacuation platforms operate in Southern Afghanistan: UK Medical Emergency Response Team (MERT), US Air Force Expeditionary Rescue Squadron (PEDRO), and US Army Medical Evacuation Squadrons (DUSTOFF), each with a different clinical capability. Recent evidence suggests that retrieval by a platform with a greater clinical capability (MERT) is associated with improved mortality in critical patients when compared with platforms with less clinical capability (PEDRO and DUSTOFF). It is unclear whether this is due to en route resuscitation or the dispatch procedure. The aim of this study was to compare prehospital Shock Index (SI = heart rate / systolic blood pressure) with admission values as a measure of resuscitation, across these platforms. Patients were identified from the Department of Defense Trauma Registry, who were evacuated between June 2009 and June 2011 in Southern Afghanistan. Data on platform type, physiology, and injury severity was extracted. Overall, 865 patients were identified: 478 MERT, 291 PEDRO, and 96 DUSTOFF patients and groups were compared across three injury severity scoring (ISS) bins: 1 to 9, 10 to 25, and 26 or greater. An improvement in the admission SI was observed across all platforms in the lowest ISS bin. Within the middle bin, both the MERT and PEDRO groups saw improved SI on admission, but not the DUSTOFF group. This trend was continued only in the MERT group for the highest ISS bin (1.39 ± 0.62 vs. 1.09 ± 0.42; P = 0.001), whereas a deterioration was identified in the PEDRO group (0.88 ± 0.37 vs. 1.02 ± 0.43; P = 0.440). The use of a Forward Aeromedical Evacuation platform with a greater clinical capability is associated with an improved hemodynamic status in critical casualties. The ideal prehospital triage should endeavor to match patient need with clinical capability.

Destination healthcare facility of shocked trauma patients in Scotland: analysis of transfusion and surgical capability of receiving hospitals.

AIMS: Haemorrhage is a leading cause of death from trauma. Management requires a combination of haemorrhage control and resuscitation which may incur significant surgical and transfusion utilisation. The aim of this study is to evaluate the resource provision of the destination hospital of Scottish trauma patients exhibiting evidence of pre-hospital shock. METHODS: Patients who sustained a traumatic injury between November 2008 and October 2010 were retrospectively identified from the Scottish Ambulance Service electronic patients record system. Patients with a systolic blood pressure less than 110 mmHg or if missing, a heart rate greater than 120 bpm, were considered in shock. The level of the destination healthcare facility was classified in terms of surgical and transfusion capability. Patients with and without shock were compared. RESULTS: There were 135,004 patients identified, 133,651 (99.0%) of whom had sustained blunt trauma, 68,411 (50.7%) were male and the median (IQR) age was 59 (46). There were 6721 (5.0%) patients with shock, with a similar age and gender distribution to non-shocked patients. Only 1332 (19.8%) of shocked patients were taken to facilities with full surgical capability, 5137 (76.4%) to hospitals with limited (general and orthopaedic surgery only) and 252 (3.7%) to hospitals with no surgical services. In terms of transfusion capability, 5556 (82.7%) shocked patients were admitted to facilities with full capability and 1165 (17.3%) to a hospital with minimal or no capability. CONCLUSIONS: The majority of Scottish trauma patients are transported to a hospital with full transfusion capability, although the majority lack surgical sub-specialty representation.

Evaluation of military trauma system practices related to damage-control resuscitation.

BACKGROUND: The Joint Theater Trauma System (JTTS) was developed with the vision that every soldier, marine, sailor, and airman injured on the battlefield would have the optimal chance for survival and maximum potential for functional recovery. In this analysis, we hypothesized that information diffusion through the JTTS, via the dissemination of clinical practice guidelines and process improvements, would be associated with the acceptance of evidence-based practices and decreases in trauma practice variability. METHODS: The current evaluation was designed as a single time-series quasi-experimental study as a preanalysis and postanalysis relative to the implementation of clinical practice guidelines and process improvement interventions. Data captured from patients admitted to hospital-level (Level III) military treatment facilities in Iraq and Afghanistan from 2003 to 2010 were retrospectively analyzed from the Joint Theater Trauma Registry (JTTR) to determine the potential impact of process improvement initiatives on clinical practice. RESULTS: The JTTS clinical practice guidelines for massive transfusion led to increased compliance with balanced component transfusion and decreased practice variability. During the course of the evaluation period, hypothermia on presentation decreased dramatically after the publication of the hypothermia prevention and management clinical practice guideline. CONCLUSION: Developed metrics demonstrate that evidence-based quality improvement initiatives disseminated through the JTTS were associated with improved clinical practice of resuscitation following battlefield injury. LEVEL OF EVIDENCE: Therapeutic/care management study, level IV.

Evaluation of military trauma system practices related to complications after injury.

BACKGROUND: The Joint Theater Trauma System (JTTS) was developed with the vision that every soldier, marine, sailor, and airman injured on the battlefield would have the optimal chance for survival and maximum potential for functional recovery. In this analysis, we hypothesized that injury and complication after injury surveillance information diffusion through the JTTS, via the dissemination of clinical practice guidelines and process improvements, would be associated with improved combat casualty clinical outcomes. METHODS: The current analysis was designed to profile different aspects of trauma system performance improvement, including monitoring of frequent posttraumatic complications, the assessment of an emerging complication trend, and measurement of the impact of the system interventions to identify potential practices for future performance improvement. Data captured from the Joint Theater Trauma Registry on patients admitted to military medical treatment facilities as a result of wounds incurred in Iraq and Afghanistan from 2003 to 2010 were retrospectively analyzed to determine the potential impact of complication surveillance and process improvement initiatives on clinical practice. RESULTS: Developed metrics demonstrated that the surveillance capacity and evidence-based quality improvement initiatives disseminated through the JTTS were associated with improved identification and mitigation of complications following battlefield injury. CONCLUSION: The Joint Trauma System enables evidence-based practice across the continuum of military trauma care. Concurrent data collection and performance improvement activities at the local and system level facilitate timely clinical intervention on identified trauma complications and the subsequent measurement of the effectiveness of those interventions. LEVEL OF EVIDENCE: Epidemiologic study, level III.

Impact of critical care-trained flight paramedics on casualty survival during helicopter evacuation in the current war in Afghanistan.

BACKGROUND: The US Army pioneered medical evacuation (MEDEVAC) by helicopter, yet its system remains essentially unchanged since the Vietnam era. Care is provided by a single combat medic credentialed at the Emergency Medical Technician - Basic level. Treatment protocols, documentation, medical direction, and quality improvement processes are not standardized and vary significantly across US Army helicopter evacuation units. This is in contrast to helicopter emergency medical services that operate within the United States. Current civilian helicopter evacuation platforms are routinely staffed by critical care-trained flight paramedics (CCFP) or comparably trained flight nurses who operate under trained EMS physician medical direction using formalized protocols, standardized patient care documentation, and rigorous quality improvement processes. This study compares mortality of patients with injury from trauma between the US Army's standard helicopter evacuation system staffed with medics at the Emergency Medical Technician - Basic level (standard MEDEVAC) and one staffed with experienced CCFP using adopted civilian helicopter emergency medical services practices. METHODS: This is a retrospective study of a natural experiment. Using data from the Joint Theater Trauma Registry, 48-hour mortality for severely injured patients (injury severity score ≥ 16) was compared between patients transported by standard MEDEVAC units and CCFP air ambulance units. RESULTS: The 48-hour mortality for the CCFP-treated patients was 8% compared to 15% for the standard MEDEVAC patients. After adjustment for covariates, the CCFP system was associated with a 66% lower estimated risk of 48-hour mortality compared to the standard MEDEVAC system. CONCLUSIONS: These findings demonstrate that using an air ambulance system based on modern civilian helicopter EMS practice was associated with a lower estimated risk of 48-hour mortality among severely injured patients in a combat setting.

Interpreting comparative died of wounds rates as a quality benchmark of combat casualty care.

BACKGROUND: The died of wounds (DOW) rate is cited as a measure of combat casualty care effectiveness without the context of injury severity or insight into lethality of the battlefield. The objective of this study was to characterize injury severity and other factors related to variations in the DOW rate. METHODS: The highest monthly DOW (HDOW) and lowest monthly DOW (LDOW) rates from 2004 to 2008 were identified from analysis and casualty report databases and used to direct a search of the Joint Theater Trauma Registry. Casualties from the HDOW and LDOW were combined into cohorts, and injury data were analyzed and compared. RESULTS: The HDOW rates were 13.4%, 11.6%, and 12.8% (mean, 12.6%), and the LDOW rates were 1.3%, 2.0%, and 2.7% (mean, 2.0%) (p < 0.0001). The HDOW (n = 541) and LDOW (n = 349) groups sustained a total of 1,154 wounds. Injury Severity Score was greater in the HDOW than the LDOW group (mean [SD], 11.1 [0.53] vs. 9.4 [0.58]; p = 0.03) as was the percentage of patients with Injury Severity Score of more than 25 (HDOW, 12% vs. LDOW, 7.7%; p = 0.04). Excluding minor injuries (Abbreviated Injury Scale score of 1), there was a greater percentage of chest injuries in the HDOW compared with the LDOW group (16.5% vs. 11.2%, p = 0.03). Explosive mechanisms were more commonly the cause of injury in the HDOW group (58.7% vs. 49.7%; p = 0.007), which also had a higher percentage of Marine Corps personnel (p = 0.02). CONCLUSION: This study provides novel data demonstrating that the died of wounds rate ranges significantly throughout the course of combat. Discernible differences in injury severity, wounding patterns, and even service affiliation exist within this variation. For accuracy, the died of wounds rate should be cited only in the context of associated injury patterns, injury severity, and mechanisms of injury. Without this context, DOW should not be used as a comparative medical metric.

Utilizing a trauma systems approach to benchmark and improve combat casualty care.

BACKGROUND: Derived from the necessity to improve the outcomes of soldiers injured on the battlefield, the U.S. military forces developed and implemented the Joint Theater Trauma System (JTTS) and the Joint Theater Trauma Registry based on U.S. civilian trauma system models. The purpose of this analysis was to develop battlefield injury outcome benchmark metrics and to evaluate the impact of JTTS-driven performance improvement interventions. METHODS: To quantify these achievements, the Joint Theater Trauma Registry captured mechanistic, physiologic, diagnostic, therapeutic, and outcome data on 18,377 injured patients from January 2004 to May 2008 for analysis. Benchmarks were developed and statistically validated by using control chart methodology. RESULTS: The majority (66.4%) of battlefield wounds were penetrating mechanism, 23.3% of all patients had an Injury Severity Score of > or = 16, 21.8% had a base deficit of > or = 5, 30.5% of patients required blood, and 6.8% required massive transfusion (> or = 10 units red blood cell per 24 hours). In this severely injured population from the battlefield, the JTTS developed several pertinent benchmark metrics to assess quality of care associated with postinjury complications and mortality. The implementation of 27 JTTS-developed evidenced-based clinical practice guidelines and an improved information dissemination process was associated with a decrease in aggregate postinjury complications by 54%. CONCLUSIONS: Despite the numerous challenges of a global trauma system, the JTTS has set the standard for trauma care on the modern battlefield utilizing evidence-based medicine. The development of injury care benchmarks enhanced the evolution of the combat casualty care performance improvement process within the trauma system.

Injury severity and causes of death from Operation Iraqi Freedom and Operation Enduring Freedom: 2003-2004 versus 2006.

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.