Management of Combat Casualties during Aeromedical Evacuation from a Role 2 to a Role 3 Medical Facility.

INTRODUCTION: Emergent clinical care and patient movements through the military evacuation system improves survival. Patient management differs when transporting from the point-of-injury (POI) to the first medical treatment facility (MTF) versus transporting from the Role 2 to the Role 3 MTF secondary to care rendered within the MTF, including surgery and advanced resuscitation. The objective of this study was to describe care provided to patients during theater inter-facility transports and compare with pre-hospital transports (POI to first MTF). MATERIALS AND METHODS: We performed a retrospective chart review of patients with the Role 2 to the Role 3 transports in Afghanistan and Iraq from 2007 to 2016. Data collected included procedures and events at the MTF and during transport. We compared the intra-theater transport data (Role 2 to Role 3) to data from a previous study evaluating pre-hospiital transports (POI to first MTF). RESULTS: We reviewed the records of 869 Role 2 to Role 3 transport patients. Role 2 to Role 3 transports were longer in duration compared to POI transports (39 minutes vs. 23 minutes) and were more likely to be staffed by advanced personnel (nurses, physician assistants, and physicians) (57% vs. 3%). The sample primarily consisted of military-aged males (mean age 27 years) who suffered from explosive or blunt force injuries. Procedures performed during each phase of care reflected the capabilities of the teams and locations. Pain and cardiac events were more common in POI evacuations compared to the Role 2 to Role 3 transports, but documentation of respiratory events, hemodynamic events, neurologic events, and equipment failure was more common during the Role 2 to Role 3 transports. Survival rates were slightly higher among the Role 2 to Role 3 cohort (98% vs. 95%, difference 3% [95% confidence interval of the difference 1-5%]). CONCLUSIONS: Inter-facility transports (Role 2 to Role 3) are longer in duration, transport more complex patients, and are staffed by more advanced level provider types compared to transports from POI.

Injuries and Interventions on Transported Military Working Dogs Within the US Central Command.

BACKGROUND: Limited veterinary care is available in the far forward environment, leading to human medical personnel being responsible, in part, for treatment of military working dogs (MWD). Though guidelines for MWD care exist, there is little research on the care and treatment of MWDs by human medical personnel. There is a lot of research on the care and treatment of MWDs. METHODS: This is a secondary analysis of a dataset from the Transportation Command (TRANSCOM) Regulating Command & Control and Evacuation System (TRAC2ES) database within the US Central Command (CENTCOM) from 2008 to 2018. Within this dataset specific to regulated transport from locations within CENTCOM, we abstracted all entries involving MWDs and analyzed causes of injury, type of injury, and interventions performed on traumatically and non-traumatically injured MWDs. RESULTS: Within our dataset, there were 84 MWD cases for analysis. Of those, 36 (43%) were transported for traumatic injuries, and the remaining 48 (57%) were transported for other medical ailments. The most common cause of trauma was gunshot wound (31%), followed by explosion (22%). The majority of trauma MWDs had injuries to the extremities (67%), and hemorrhage requiring intervention occurred in 25%. The most common interventions performed on traumas were analgesia (67%), antibiotics (31%), IV fluids (28%), and surgery (31%). The most common indications that occurred in MWDs treated for nontraumatic medical indications were gastrointestinal diseases (33%), followed by nontraumatic orthopedic injuries (21%). CONCLUSIONS: Of the MWDs in our dataset, most were transported for nontraumatic medical events. The most frequent intervention performed was medication administration for both traumatic and medical ailments. Our dataset adds to the limited body of MWD data from theater.

Characterization of Long-range Aeromedical Transport and Its Relationship to the Development of Traumatic Extremity Compartment Syndrome: A 7-year, Retrospective Study.

BACKGROUND: Military aeromedical transport evacuates critically injured patients are for definitive care, including patients with or at risk for developing traumatic compartment syndrome of the extremities (tCSoE). Compartment pressure changes of the extremities have not been determined to be associated with factors inherent to aeromedical transport in animal models, but the influence of aeromedical evacuation (AE) transport on the timing of tCSoE development has not been studied in humans. Using a registry-based methodology, this study sought to characterize the temporal features of lower extremity compartment syndrome relative to the timing of transcontinental AE. With this approach, this study aims to inform practice in guidelines relating to the timing and possible effects of long-distance AE and the development of lower extremity compartment syndrome. Using patient care records, we sought to characterize the temporal features of tCSoE diagnosis relative to long-range aeromedical transport. In doing so, we aim to inform practice in guidelines relating to the timing and risks of long-range AE and postulate whether there is an ideal time to transport patients who are at risk for or with tCSoE. METHODS: We performed a retrospective record review of patients with a diagnosis of tCSoE who were evacuated out of theater from January 2007 to May 2014 via aeromedical transport. Data abstractors collected flight information, laboratory values, vital signs, procedures, in-flight assessments, and outcomes. We used the duration of time from injury to arrival at Landstuhl Regional Medical Center (LRMC) to represent time to transport. We compared groups based on time of tCSoE (inclusive of upper and lower extremity) diagnosis relative to injury day and time of transport (preflight versus postflight). We used descriptive statistics and multivariable regression models to determine the associations between time to transport, time to tCSoE diagnosis, and outcomes. RESULTS: Within our study window, 238 patients had documentation of tCSoE. We found that 47% of patients with tCSoE were diagnosed preflight and 53% were diagnosed postflight. Over 90% in both groups developed tCSoE within 48 hours of injury; the time to diagnosis was similar for casualties diagnosed pre- and postflight (P = .65). There was no association between time to arrival at LRMC and day of tCSoE diagnosis (risk ratio, 1.06; 95% CI, 0.96-1.16). CONCLUSION: The timing of tCSoE diagnosis is not associated with the timing of transport; therefore, AE likely does not influence the development of tCSoE.

Impact of a Standardized EMS Handoff Tool on Inpatient Medical Record Documentation at a Level I Trauma Center.

BACKGROUND: The emergency department (ED) poses challenges to effective handoff from emergency medical services (EMS) personnel to ED staff. Despite the importance of a complete and accurate patient handoff report between EMS and trauma staff, communication is often interrupted, incomplete, or otherwise ineffective. The Mechanism of injury/Medical Complaint, Injuries or Inspections head to toe, vital Signs, and Treatments (MIST) report initiative was implemented to standardize the handoff process. The objective of this study was to evaluate whether documentation of prehospital care in the inpatient medical record improved after MIST implementation. METHODS: Research staff abstracted data from the EMS and inpatient medical records of trauma patients transported by EMS and treated at a Level I trauma center from January 2015 through June 2017. Data included patient demographics, mechanism and location of injury, vital signs, treatments, and period of data collection (pre-MIST and post-MIST). We summarized the MIST elements in EMS and inpatient medical records and assessed the presence or absence of data elements in the inpatient record from the EMS record and the agreement between the two sets of records over time to determine if implementation of MIST improved documentation. RESULTS: We analyzed data from 533 trauma patients transported by EMS and treated in a Level I trauma center (pre-MIST: n = 281; post-MIST: n = 252). For mechanism of injury, agreement between the two records was ≥96% before and after MIST implementation. Cardiac arrest and location of injury were under-reported in the inpatient record before MIST; post-MIST, there were no significant discrepancies, indicating an improvement in reporting. Reporting of prehospital hypotension improved from 76.5% pre-MIST to 83.3% post-MIST. After MIST implementation, agreement between the EMS and inpatient records increased for the reporting of fluid administration (45.6% to 62.7%) and decreased for reporting of pain medications (72.2% to 61.9%). CONCLUSIONS: The use of the standardized MIST tool for EMS to hospital patient handoff was associated with a mixed value on inpatient documentation of prehospital events. After MIST implementation, agreement was higher for mechanism and location of injury and lower for vital signs and treatments. Further research can advance the prehospital to treatment facility handoff process.

Impact of a Standardized Patient Hand-off Tool on Communication between Emergency Medical Services Personnel and Emergency Department Staff.

INTRODUCTION: Handoff communication between Emergency Medical Services (EMS) and Emergency Department (ED) staff is critical to ensure quality patient care. In January 2016, the Southwest Texas Regional Advisory Council (STRAC) implemented MIST (Mechanism, Injuries, vital Signs, Treatments), a standardized EMS to ED handoff tool. The En route Care Research Center conducted a Pre-MIST implementation survey of ED staff in December 2015 and a Post-MIST follow-up survey in July 2017 to determine the impact of the MIST handoff tool on the perceived quality of transmission of pertinent patient information and in the overall handoff experience. METHODS: We administered a nine-item Likert scale questionnaire to Brooke Army Military Medical Center (BAMC) ED providers and nurses before and after implementation of MIST. The questionnaire captured perceived competence and satisfaction with handoff communication (Cronbach's alpha 0.73). We analyzed responses for the total sample and by occupation (providers and nurses), and we calculated odds ratios to determine items that may be most predictive of a positive handoff experience from the perspective of the ED staff. We performed chi-square tests and reported data as percentages. RESULTS: Total respondents Pre- and Post-MIST were 128 (62%) nurses and 80 (38%) providers (MDs, DOs, and PAs). Following the implementation of MIST, more respondents reported that they were "informed of prehospital treatments" (p < 0.001), that "Red/Blue Trauma Alert Criteria were conveyed" (p < 0.001), and that the "time to give the report was sufficient to convey pertinent information" (p < 0.001). Nurses more frequently reported that "Red/Blue Trauma Alert Criteria were conveyed" post-MIST (p < 0.01). Providers more frequently reported that "Assessment findings were conveyed" (p < 0.05), that they 'interrupted the report for clarification" (p < 0.04), that "time to give the report was sufficient to convey pertinent information" (p < 0.001) and that they "felt positive about the overall handoff experience" (p < 0.03) Post-MIST. Overall satisfaction with the handoff was associated with frequently being informed of prehospital treatments (OR 5.5; 2.1-14.4) and frequently receiving a copy of the prehospital record (OR 2.9; 1.1-7.2). CONCLUSIONS: These data demonstrate that providers and nurses reported an improvement in the handoff experience Post-MIST. This study supports the use of a standardized handoff tool at this critical step in patient care.

Development and Evaluation of An Abbreviated Extracorporeal Membrane Oxygenation (ECMO) Course for Nonsurgical Physicians and Nurses.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) is a modification of cardiopulmonary bypass that allows prolonged support of patients with severe respiratory or cardiac failure. ECMO indications arse rapidly evolving and there is growing interest in its use for cardiac arrest and cardiogenic shock. However, ECMO training programs are limited. Training of emergency medicine and critical care clinicians could expand the use of this lifesaving intervention. Our objective was to develop and evaluate an abbreviated ECMO course that can be taught to emergency and critical care physicians and nurses. METHODS: We developed a training model using Yorkshire swine (Sus scrofa), a procedure instruction checklist, a confidence assessment, and a knowledge assessment. Participants were assigned to teams of one emergency medicine or critical care physician and one nurse and completed an abbreviated 8-hour ECMO course. An ECMO specialist trained participants on preparation of the ECMO circuit and oversaw vascular access and ECMO initiation. We used the instruction checklist to evaluate performance. Participants completed confidence and knowledge assessments before and after the course. RESULTS: Seventeen teams (34 clinicians) completed the abbreviated ECMO course. None had previously completed an ECMO certification course. Immediately following the course, all teams successfully primed and prepared the ECMO circuit. Fifteen teams (88%, 95% confidence interval [CI] = 64% to 99%) successfully initiated ECMO. Participants improved their knowledge (difference 21.2, 95% CI = 16.5 to 25.8) and confidence (difference 40.3, 95% CI = 35.6 to 45.0) scores after completing the course. CONCLUSIONS: We developed an accelerated 1-day ECMO course. Clinicians' confidence and knowledge assessments improved and 88% of teams could successfully initiate venoarterial ECMO after the course.

Patients With Traumatic Brain Injury Transported by Critical Care Air Transport Teams: The Influence of Altitude and Oxygenation during Transport.

INTRODUCTION: Traumatic brain injuries (TBIs) are life-threatening, and air transport of patients with TBI requires additional considerations. To mitigate the risks of complications associated with altitude, some patients fly with a cabin altitude restriction (CAR) to limit the altitude at which an aircraft's cabin is maintained. The goal of this study was to examine the effects of CARs on patients with TBI transported out of theater via Critical Care Air Transport Teams. MATERIALS AND METHODS: We conducted a retrospective chart review of patients with moderate-to-severe TBI evacuated out of combat theater to Landstuhl Regional Medical Center via Critical Care Air Transport Teams. We collected demographics, flight and injury information, procedures, oxygenation, and outcomes (discharge disposition and hospital/ICU/ventilator days). We categorized patients as having a CAR if they had a documented CAR or maximum cabin altitude of 5,000 feet or lower in their Critical Care Air Transport Teams record. We calculated descriptive statistics and constructed regression models to evaluate the association between CAR and clinical outcomes. RESULTS: We reviewed the charts of 435 patients, 31% of which had a documented CAR. Nineteen percent of the sample had a PaO2 lower than 80 mm Hg, and 3% of patients experienced a SpO2 lower than 93% while in flight. When comparing preflight and in-flight events, we found that the percentage of patients who had a SpO2 of 93% or lower increased for the No CAR group, whereas the CAR group did not experience a significant change. However, flying without a CAR was not associated with discharge disposition, mortality, or hospital/ICU/ventilator days. Further, having a CAR was not associated with these outcomes after adjusting for additional flights, injury severity, injury type, or preflight head surgery. CONCLUSIONS: Patients with TBI who flew with a CAR did not differ in clinical outcomes from those without a CAR.

Prehospital Life-Saving Interventions Performed on Pediatric Patients in a Combat Zone: A Multicenter Prospective Study.

OBJECTIVES: We aimed to describe and evaluate prehospital life-saving interventions performed in a pediatric population in the Afghanistan theater of operations. DESIGN: Our study was a post hoc, subanalysis of a larger multicenter, prospective, observational study. SETTING: We evaluated casualties enrolled upon admission to one of the nine military medical facilities in Afghanistan between January 2009 and March 2014. PATIENTS: Adult and pediatric (<17 yr old) patients. MEASUREMENTS: We conducted initial descriptive analyses followed by comparative tests. For comparative analysis, we stratified the study population (adult vs pediatric), and subsequently, we compared injury descriptions and the interventions performed. Following tests for normality, we used the t test or Wilcoxon rank-sum test (nonparametric) for continuous variables and chi-square or Fisher exact for categorical variables. We reported percentages and 95% CIs. MAIN RESULTS: We enrolled 2,106 patients, of which 5.6% (n = 118) were pediatric. Eighty-two percent of the pediatric patients were male, and 435 had blast related injuries. A total of 295 prehospital life-saving interventions were performed on 118 pediatric patients, for an average of 2.5 life-saving interventions per patient. Vascular access (IV 96%, intraosseous 91%) and hypothermia prevention-related interventions (69%) were the most common. Incorrectly performed life-saving interventions in pediatric patients were rare (98% of life-saving interventions performed correctly) and n equals to 24 life-saving interventions over the 6-year period were missed. The most common incorrectly performed and missed life-saving interventions were related to vascular access. When compared with adult life-saving interventions received in the prehospital environment, pediatric patients were more likely to receive intraosseous access (p < 0.0001), whereas adult patients were more likely to have a tourniquet placed (p = 0.0019), receive wound packing with a hemostatic agent (p = 0.0091), and receive chest interventions (p = 0.0003). CONCLUSIONS: In our study, the most common intervention was vascular access followed by hypothermia prevention and hemorrhage control. The occurrence of missed or incorrectly performed life-saving interventions were rare.

Prehospital Use of Ketamine in the Combat Setting: A Sub-Analysis of Patients With Head Injuries Evaluated in the Prospective Life Saving Intervention Study.

OBJECTIVES: Ketamine is used as an analgesic for combat injuries. Ketamine may worsen brain injury, but new studies suggest neuroprotection. Our objective was to report the outcomes of combat casualties with traumatic brain injury (TBI) who received prehospital ketamine. METHODS: This was a post hoc, sub-analysis of a larger prospective, multicenter study (the Life Saving Intervention study [LSI]) evaluating prehospital interventions performed in Afghanistan. A DoD Trauma Registry query provided disposition at discharge and outcomes to be linked with the LSI data. RESULTS: For this study, we enrolled casualties that were suspected to have TBI (n = 160). Most were 26-year-old males (98%) with explosion-related injuries (66%), a median injury severity score of 12, and 5% mortality. Fifty-seven percent (n = 91) received an analgesic, 29% (n = 46) ketamine, 28% (n = 45) other analgesic (OA), and 43% (n = 69) no analgesic (NA). The ketamine group had more pelvic injuries (P = 0.0302) and tourniquets (P = 0.0041) compared to OA. In comparison to NA, the ketamine group was more severely injured and more likely to require LSI procedures, yet, had similar vital signs at admission and disposition at discharge. CONCLUSIONS: We found that combat casualties with suspected TBI that received prehospital ketamine had similar outcomes to those that received OAs or NAs despite injury differences.

Interventions Performed on Multipurpose Military Working Dogs in the Prehospital Combat Setting: A Comprehensive Case Series Report.

INTRODUCTION: The military working dog (MWD) has been essential in military operations such as Operation Iraqi Freedom (OIF) and Operation Enduring Freedom (OEF). MWDs sustain traumatic injuries that require point of injury and en route clinical interventions. The objective of this study was to describe the injuries and treatment military working dogs received on the battlefield and report their final disposition. METHODS: This was a convenience sample of 11 injury and treatment reports of US MWDs from February 2008 to December 2014. We obtained clinical data regarding battlefield treatment from the 160th Special Operations Aviation Regiment (SOAR) database and supplemental operational sources. A single individual collected the data and maintained the dataset. The data collected included mechanism of injury, clinical interventions, and outcomes. We reported findings as frequencies. RESULTS: Of the 11 MWD casualties identified in this dataset, 10 reports had documented injuries secondary to trauma. Eighty percent of the cases sustained gunshot wounds. The hindlegs were the most common site of injury (50%); however, 80% sustained injuries at more than one anatomical location. Seventy percent of cases received at least one clinical intervention before arrival at their first treatment facility. The most common interventions included trauma dressing (30%), gauze (30%), chest seal (30%), and pain medication (30%). The survival rate was 50%. CONCLUSION: The majority of the MWD cases in this dataset sustained traumatic injuries, with gunshot being the most common mechanism of injury. Most MWDs received at least one clinical intervention. Fifty percent did not survive their traumatic injuries.

Descriptive Analysis of Cardiac Patients Transported by Critical Care Air Transport Teams.

INTRODUCTION: Critical Care Air Transport Teams (CCATTs) transport critically ill patients within and out of theaters of combat operations. Studies of the CCATT population reveal as many as 35% of patients have a non-trauma diagnosis, of which more than half are cardiac.The purpose of this retrospective study was to describe the epidemiology of critically ill patients with cardiac diagnoses evacuated from theater via CCATT. MATERIALS AND METHODS: We conducted a retrospective review of 290 medical patients with a primary cardiac diagnosis transported from any theater of operation to Landstuhl Regional Medical Center, Germany from January 2007 to April 2015. RESULTS: The majority of patients were male with an average age of 46 ± 11 years, US contractors (47%, n = 137), followed by US Active Duty (32%, n = 93). Patients had an average BMI of 29 ± 5; 62% of cardiac patients were either overweight or obese. The most common cardiac diagnoses were ST elevation myocardial infarction, Non-ST elevation myocardial infarction, and angina. Pre-flight vital signs indicate overall patients were stable prior to evacuation, with the majority receiving supplemental oxygen and only 5% requiring mechanical ventilation. Eighty-one percent of patients experienced at least one cardiac event during flight, however less than 5% required adjustment to oxygen or ventilator settings. CONCLUSIONS: Critically ill cardiac patients make up a significant portion of patients transported out of the combat theater. These patients are older, overweight and have identified risk factors for cardiac morbidity. More strenuous pre-deployment screening for risk factors and prevention strategies could minimize the use of military resources to evacuate these patients from the combat theater.

En Route Care Provided by US Navy Nurses in Iraq and Afghanistan.

BACKGROUND: US Navy nurses provide en route care for critically injured combat casualties without having a formal program for training, utilization, or evaluation. Little is known about missions supported by Navy nurses. OBJECTIVES: To characterize the number and types of patients transported and skill sets required by Navy nurses during 2 combat support deployments. METHODS: All interfacility casualty transfers between 2 separate facilities in Iraq and Afghanistan were assessed. Number of patients treated, number transported, en route care provider type, transport priority level and duration, injury severity, indication for critical care transport, en route care interventions, and vital signs were evaluated. RESULTS: Of 1550 casualties, 630 required medical evacuation to a higher level of care. Of those, 133 (21%) were transported by a Navy nurse, with 131 (98.5%) classified as "urgent," accounting for 46% of all urgent transports. The primary indication for en route care nursing was mechanical ventilation of intubated patients (97%). Mean (SD) patient transport time was 29.8 (7.9) minutes (range, 17-61 minutes). The most common en route care interventions were administration of intravenous sedation (80%), neuromuscular blockade (79%), and opioids (48%); transfusions (18%); and ventilation changes (11%). No intubations, cricothyroidotomies, chest tube placements, or needle decompressions were performed en route. No deaths occurred during transport. CONCLUSIONS: US Navy nurses successfully transported critically injured patients without observed adverse events. Establishing en route care as a program of record in the Navy will facilitate continuous process improvement to ensure that future casualties receive optimized en route care.

Critical Care Air Transport Team Evacuation of Medical Patients Without Traumatic Injury.

BACKGROUND: Air Force Critical Care Air Transport Teams (CCATTs) provide fixed-wing aeromedical evacuation for combat casualties. Multiple studies have evaluated CCATT trauma patients; however, nearly 50% of patients medically evacuated from combat theaters are for nontraumatic medical illnesses to include stroke, myocardial infarctions, overdose, and pulmonary emboli. Published data are limited regarding illness types, in-flight procedures, and adverse events. OBJECTIVE: The objective of our study was to characterize patients with nontraumatic medical illnesses transferred via CCATT to include a description of in-flight procedures and events. STUDY DESIGN: We performed a retrospective review of CCATT medical records of patients with nontraumatic medical illnesses transported via CCATT from theater of operations to Landstuhl Regional Medical Center between January 2007 and April 2015. We abstracted data from CCATT records to include demographics, description of current illness, vital signs, labs, in-flight procedures and medications, and in-flight adverse events. Following descriptive analysis, comparative tests were performed based on service status of patients and primary diagnoses. RESULTS: We reviewed 672 records of critically ill medical patients transported via CCATT, most of whom were male (90%, n = 606). Approximately 56% of the patients were U.S. active duty members; the remainder included U.S. contractors and civilians, and foreign citizens or unknown. The three categories (active duty, contractor/civilian, foreign/unknown) significantly differed from one another in age. Over half of the patients received a primary or secondary cardiac diagnosis. The most common in-flight procedures and medications included supplementary oxygenation, anticoagulant/antiplatelet medications, analgesics, and ventilation. Up to 20% of patients required continuous medication infusions other than analgesics. Patients most frequently experienced in-flight complications related to their primary diagnoses. CONCLUSIONS: Fifty-six percent (672) of 1,209 CCATT records that were queried were of patients with medical conditions. The most common primary diagnoses of CCATT medical patients were cardiac, pulmonary, and neurological in etiology. Mechanical ventilation and continuous medication infusions were required in approximately 20% of patients. The data provided by this study may assist in guiding future CCATT training requirements and resource allocation, as well as clinical practice guideline development.

Combat MEDEVAC: A comparison of care by provider type for en route trauma care in theater and 30-day patient outcomes.

BACKGROUND: Medical evacuation (MEDEVAC) is the movement and en route care of injured and medically compromised patients by medical care providers via helicopter. Military MEDEVAC platforms provide lifesaving interventions that improve survival in combat. There is limited evidence to support decision making related to en route care and allocation of resources. The association between provider type and en route care is not well understood. Our objective was to describe MEDEVAC providers and identify associations between provider type, procedures performed, and outcomes. METHODS: We conducted an institutional review board-approved, retrospective record review of patients traumatically injured in combat, evacuated by MEDEVAC from the point of injury, between 2011 and 2014. Data abstracted included injury description, provider type, procedures performed, medications administered, survival, and 30-day outcomes. Subjects were grouped according to provider type: medics, paramedics, and ADVs (advanced-level providers to include nurses, physician assistants, and physicians). Groups were compared. Analyses were performed using χ tests for categorical variables and analysis of variance tests (Kruskal-Wallis tests) for continuous variables; p < 0.05 was considered significant. RESULTS: The MEDEVAC records were reviewed, and data were abstracted from 1,237 subjects. The providers were composed of medics, 76%; paramedics, 21%; and ADVs, 4%. Patient and injury demographics were similar among groups. The ADVs were most likely to perform intubation, chest needle decompressions (p < 0.0001), and hypothermia prevention (p = 0.01). Paramedics were most likely to administer blood en route (p < 0.0001). All other procedures were similar between groups. Paramedics were most likely to administer ketamine (p < 0.0001), any analgesic (p < 0.0001), or any medication en route (p < 0.0001). Incidence rates of en route events (pain, hypoxia, abnormal hemodynamics, vital signs) were similar between provider types. In-theater and 30-day survival rates were similar between provider types. CONCLUSION: Providers with higher-level training were more likely to perform more advanced procedures during en route care. Our study found no significant association between provider type and in-theater or 30-day mortality rates. Upon subgroup analysis, no difference was found in patients with an injury severity score greater than 16. More evidence is needed to determine the appropriate level of MEDEVAC personnel training and skill maintenance necessary to minimize combat mortality. LEVEL OF EVIDENCE: Therapeutic study, level III.