A Descriptive Study of Casualties Evacuated Out of Afghanistan by Critical Care Air Transport Teams During the Withdrawal of U.S. Troops

INTRODUCTION

The War in Afghanistan ended in August 2021. Evacuation from the country was a large effort during the last days of the conflict. During evacuation efforts at Kabul Hamid Karzai International Airport, a suicide bombing occurred necessitating emergent medical care for many injured troops and civilians. The U.S. Air Force Critical Care Air Transport Teams (CCATTs) played a role in the medical care provided during the operations in Afghanistan. We report on in-flight events and interventions that took place during the final days of the Afghanistan withdrawal.

MATERIALS AND METHODS

We performed a retrospective chart review of patients requiring aeromedical evacuation from the Afghanistan theater of operations by CCATT from July 1 to August 30, 2021. From the CCATT patient care record, data abstractors collected patient characteristics, flight information, vital signs, laboratory values, in-flight interventions, and in-flight events in a study-specific electronic database. We performed descriptive analyses of patient characteristics and in-flight interventions. This study was approved by the San Antonio Institutional Review Board.

RESULTS

Nine patients were included in this analysis. Seven out of nine patients were foreign nationals; the remaining two were U.S. Marines. Five patients suffered penetrating injuries from gunshot wounds and four suffered blast injuries. Six received intravenous narcotic analgesia. Four received intravenous sedatives, and four received antibiotics in flight. Two patients required chest tube management. One patient received blood. Three patients were in acute respiratory distress.

CONCLUSIONS

Severe injuries were sustained during the withdrawal efforts at the end of the War in Afghanistan. Critical Care Air Transport Teams played a role in the care and evacuation of patients out of theater during this unique and unprecedented time. Even given the limitations associated with retrospective studies and a small sample size, information reported in this study can help inform future decisions, and aid in preparatory efforts for future operations, that may require medical care by CCATT.

A Retrospective Cohort Study of Burn Casualties Transported by the US Army Burn Flight Team and US Air Force Critical Care Air Transport Teams

INTRODUCTION

The US Army Burn Center, the only burn center in the Department of Defense provides comprehensive burn care. The Burn Flight Team (BFT) provides specialized burn care during transcontinental evacuation. During Operations Iraqi and Enduring Freedom, burn injuries accounted for approximately 5% of all injuries in military personnel. To augment BFT capacity, US Air Force Critical Care Air Transport Teams (CCATTs) mobilized to transport burn patients. The purpose of this study was to describe critically ill, burn injured patients transported to the US Army Burn Center by BFT or CCATT, to compare and contrast characteristics, evacuation procedures, in-flight treatments, patient injuries/illnesses, and outcomes between the two groups.

MATERIALS AND METHODS

We conducted a retrospective cohort study of CCATT and BFT patients, admitted to the burn ICU between January 1, 2001 and September 30, 2018. Patients with total body surface area burned (TBSA) >30% were evacuated by BFT, while CCATT evacuated patients with ≤ 30% TBSA.

RESULTS

Ninety-seven patients met inclusion criteria for this study. Of these, 40 (41%) were transported by the BFT and 57 (59%) were transported by CCATTs. Compared with patients transported by CCATTs, patients transferred by the BFT had higher median TBSA and full-thickness burn size, higher prevalence of chest, back and groin burns, and higher prevalence of inhalation injury. BFT patients had increased hospital days (62 vs. 37; P = .08), ICU days (29 vs. 12; P = .003) and ventilator days (14 vs. 6; P  < .001). TBSA was the only variable significantly associated with ARDS (aOR = 1.04; 95% CI: 1.01, 1.08; P = 0.04), renal failure (aOR = 1.07; 95% CI: 1.03, 1.11; P = .002), and mortality (aOR = 1.08; 95% CI: 1.03, 1.13; P = .001).

CONCLUSIONS

Evacuation by the BFT was associated with increased ICU and ventilator days, increased mortality, and a greater risk for developing renal failure. The severity of injury/TBSA likely accounted for most of these differences.

Evacuation Strategies for U.S. Casualties with Traumatic Brain Injury (TBI) with and without Polytrauma

INTRODUCTION

According to the Military Health System Traumatic Brain Injury (TBI) Center of Excellence, 51,261 service members suffered moderate to severe TBI in the last 21 years. Moderate to severe TBI in service members is usually related to blast injury in combat operations, which necessitates medical evacuation to higher levels of care. Prevention of secondary insult, and mitigation of the unique challenges associated with the transport of TBI patients in a combat setting are important in reducing the morbidity and mortality associated with this injury. The primary goal of this study was a secondary analysis comparing the impact of time to transport on clinical outcomes for TBI patients without polytrauma versus TBI patients with polytrauma transported out of the combat theater via Critical Care Air Transport Teams (CCATT). Our secondary objective was to describe the occurrence of in-flight events and interventions for TBI patients without polytrauma versus TBI with polytrauma to assist with mission planning for future transports.

MATERIALS AND METHODS

We performed a secondary analysis of a retrospective cohort of 438 patients with TBI who were evacuated out of theater by CCATT from January 2007 to May 2014. Polytrauma was defined as abbreviated injury scale (AIS) of at least three to another region in addition to head/neck. Time to transport was defined as the time (in days) from injury to CCATT evacuation out of combat theater. We calculated descriptive statistics and examined the associations between time to transport and preflight characteristics, in-flight interventions and events, and clinical outcomes for TBI patients with and without polytrauma.

RESULTS

We categorized patients into two groups, those who had a TBI without polytrauma (n = 179) and those with polytrauma (n = 259). Within each group, we further divided those that were transported within 1 day of injury, in 2 days, and 3 or more days. Patients with TBI without polytrauma transported in 1 or 2 days were more likely to have a penetrating injury, an open head injury, a preflight Glascow Coma Score (GCS) of 8 or lower, and be mechanically ventilated compared to those transported later. Patients without polytrauma who were evacuated in 1 or 2 days required more in-flight interventions compared to patients without polytrauma evacuated later. Patients with polytrauma who were transported in 2 days were more likely to receive blood products, and patients with polytrauma who were evacuated within 1 day were more likely to have had at least one episode of hypotension en route. Polytrauma patients who were evacuated in 2-3 days had higher hospital days compared to polytrauma with earlier evacuations. There was no significant difference in mortality between any of the groups.

CONCLUSIONS

In patients with moderate to severe TBI transported via CCATT, early evacuation was associated with a higher rate of in-flight hypotension in polytrauma patients. Furthermore, those who had TBI without polytrauma that were evacuated in 1-2 days received more in-flight supplementary oxygen, blood products, sedatives, and paralytics. Given the importance of minimizing secondary insults in patients with TBI, recognizing this in this subset of the population may help systematize ways to minimize such events. Traumatic Brain Injury patients with polytrauma may benefit from further treatment and stabilization in theater prior to CCATT evacuation.

Descriptive Analysis of Coronavirus Disease 2019 Air Medical Evacuations by Critical Care Air Transport Teams

OBJECTIVE

Preserving air medical evacuation capabilities for critically ill patients with coronavirus disease 2019 (COVID-19) required innovation for en route care logistics, training, and equipment. The aim of this study was to describe characteristics and in-flight interventions for patients with suspected COVID-19 requiring air medical evacuation by US Air Force critical care air transport teams (CCATTs).

METHODS

We performed a retrospective chart review of patients with suspected COVID-19 requiring air medical evacuation by CCATT from April 2020 to February 2021. We included patients with an available CCATT medical record and transport with COVID-19 infection isolation precautions. CCATT medical records were the data source, and we performed descriptive analyses of patient characteristics and in-flight interventions.

RESULTS

We reviewed 460 records and identified 16 patients for inclusion. The Transport Isolation System (50%) and Negatively Pressurized Conex (31%) were commonly used portable biocontainment units. The median patient age was 48.5 years, and 94% were male. All patients required oxygen supplementation, with 8 (50%) receiving mechanical ventilation. In-flight interventions among intubated patients (n = 8) included vasopressors (50%), paralytics (25%), and patient-ventilator asynchrony management (63%).

CONCLUSION

Patients with COVID-19 requiring CCATT transport were older than prior military en route care cohorts, and in-flight interventions for patient-ventilator asynchrony were commonly required during mechanical ventilation.

Level 1 Trauma Centers and OEF/OIF Emergency Departments: Comparison of Trauma Patient Populations

INTRODUCTION

Brooke Army Medical Center (BAMC), the largest military hospital and the only level 1 trauma center in the DoD, cares for active duty, retired uniformed services personnel, and beneficiaries. In addition, BAMC works in collaboration with the Southwest Texas Regional Advisory Council (STRAC) and University Hospital (UH), San Antonio's other level 1 trauma center, to provide trauma care to residents of the city and 22 counties in southwest Texas from San Antonio to Mexico (26,000 square mile area). Civilian-military partnerships are shown to benefit the training of military medical personnel; however, to date, there are no published reports specific to military personnel experiences within emergency care. The purpose of the current study was to describe and compare the emergency department trauma patient populations of two level 1 trauma centers in one metropolitan city (BAMC and UH) as well as determine if DoD level 1 trauma cases were representative of patients treated in OEF/OIF emergency department settings.

MATERIALS AND METHODS

We obtained a nonhuman subjects research determination for de-identified data from the US Air Force 59th Medical Wing and the University of Texas Health Science Center at San Antonio Institutional Review Boards. Data on emergency department patients treated between the years 2015 and 2017 were obtained from the two level 1 trauma centers (BAMC and UH, located in San Antonio, Texas); data included injury descriptors, ICU and hospital days, and department procedures.

RESULTS

Two-proportion Z-tests indicated that trauma patients were similar across trauma centers on injury type, injury severity, and discharge status; yet trauma patients differed significantly in terms of mechanism of injury and regions of injury. BAMC received significantly greater proportions of patients injured from falls, firearms and with facial and head injuries than UH, which received significantly greater proportion of patients with thorax and abdominal injuries. In addition, a significantly greater proportion of patients spent more than 2 days in the ICU and greater than two total hospital days at BAMC than in UH. In comparison to military emergency departments in combat zones, BAMC had significantly lower rates of blood product administration and endotracheal intubations.

CONCLUSIONS

The trauma patients treated at a military level 1 trauma center were similar to those treated in the civilian level 1 trauma center in the same city, indicating the effectiveness of the only DoD Level 1 trauma center to provide experience comparable to that provided in civilian trauma centers. However, further research is needed to determine if the exposure rates to specific procedures are adequate to meet predeployment readiness requirements.

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.

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 Critical Care Transfer From a Role 2 to a Role 3 Medical Treatment Facility in Afghanistan

BACKGROUND

En route care is the transfer of patients requiring combat casualty care within the US military evacuation system. No reports have been published about en route care of patients during transfer from a forward surgical facility (role 2) to a combat support hospital (role 3) for comprehensive care.

OBJECTIVE

To describe patients transferred from a role 2 to a role 3 US military treatment facility in Afghanistan.

METHODS

A retrospective review of data from the Joint Trauma System Role 2 Database was conducted. Patient characteristics were described by en route care medical attendants.

RESULTS

More than one-fourth of patients were intubated at transfer (26.9%), although at transfer fewer than 10% of patients had a base deficit of more than 5 (3.5%), a pH of less than 7.3 (5.2%), an international normalized ratio of more than 2 (0.8%), or temporary abdominal or chest closure (7.4%). The en route care medical attendant was most often a nurse (35.5%), followed by technicians (14.1%) and physicians (10.0%). Most patients (75.3%) were transported by medical evacuation (on rotary-wing aircraft).

CONCLUSION

This is the first comprehensive review of patients transported from a forward surgical facility to a more robust combat support hospital in Afghanistan. Understanding the epidemiology of these patients will inform provider training and the appropriate skill mix for the transfer of postsurgical patients within a combat setting.

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.

Impact of prehospital medical evacuation (MEDEVAC) transport time on combat mortality in patients with non-compressible torso injury and traumatic amputations: a retrospective study

BACKGROUND

In combat operations, patients with traumatic injuries require expeditious evacuation to improve survival. Studies have shown that long transport times are associated with increased morbidity and mortality. Limited data exist on the influence of transport time on patient outcomes with specific injury types. The objective of this study was to determine the impact of the duration of time from the initial request for medical evacuation to arrival at a medical treatment facility on morbidity and mortality in casualties with traumatic extremity amputation and non-compressible torso injury (NCTI).

METHODS

We completed a retrospective review of MEDEVAC patient care records for United States military personnel who sustained traumatic amputations and NCTI during Operation Enduring Freedom between January 2011 and March 2014. We grouped patients as traumatic amputation and NCTI (AMP+NCTI), traumatic amputation only (AMP), and neither AMP nor NCTI (Non-AMP/NCTI). Analysis was performed using chi-squared tests, Fisher's exact tests, Cochran-Armitage Trend tests, Shapiro-Wilks tests, Wilcoxon and Kruskal-Wallis techniques and Cox proportional hazards regression modeling.

RESULTS

We reviewed 1267 records, of which 669 had an injury severity score (ISS) of 10 or greater and were included in the analysis. In the study population, 15.5% sustained only amputation injuries (n=104, AMP only), 10.8% sustained amputation and NCTI (n=72, AMP+NCTI), and 73.7% did not sustain either an amputation or an NCTI (n=493, Non-AMP/NCTI). AMP+NCTI had the highest mortality (16.7%) with transport time greater than 60 min. While the AMP+NCTI group had decreasing survival with longer transport times, AMP and Non-AMP/NCTI did not exhibit the same trend.

CONCLUSIONS

A decreased transport time from the point of injury to a medical treatment facility was associated with decreased mortality in patients who suffered a combination of amputation injury and NCTI. No significant association between transport time and outcomes was found in patients who did not sustain NCTI. Priority for rapid evacuation of combat casualties should be given to those with NCTI.