Evacuation

#### EVACUATION

Air Med J. 2018 Nov - Dec;37(6):362-366

# Critical Care Skill Triad for Tactical Evacuations.

Boutonnet M, Raynaud L, Pasquier P, Vitiello L, Coste S, Ausset S

OBJECTIVE: Providing medical support to French soldiers deployed on war theater everywhere around the world is the first mission of the French Military Medical Service (FMMS). En-route critical care is critical to maintain the continuum of care and safety during forward and tactical medical evacuation (MEDEVAC). The FMMS has developed specific training programs to ensure optimal en-route critical care air transport. These courses need to be continuously adjusted to the returns of experience and to the operational changes. The aim of our survey was to characterize the critical care skills required for tactical MEDEVAC on fixed wing aircraft.

METHODS: A 10-items survey was sent to 22 flight surgeons previously deployed in the Sahel-Saharan Strip. Eight questions focused on basic critical care skills. The 2 last items assessed the flight surgeons' willingness to follow a pre deployment course in a critical care unit and in a transfusion center.

RESULTS: Fourteen of the 22 flight surgeons responded to the survey. All but one responder had to deal with at least one critical care skill. The most frequent critical care skills required were the management of mechanical ventilation, catecholamine infusion and blood product transfusion. Five of the 14 responders reported on-board blood product transfusion, including red blood cells, lyophilized plasma and fresh whole blood.

CONCLUSION: Our survey highlights the need for the MEDEVAC teams to be skilled in critical care medicine. We defined a triad of critical care skills required for the management of severe casualties, including the management of mechanical ventilation, catecholamine infusion and blood product transfusion.

Mil Med. 2018 Dec 7. Epub ahead of print

# En Route Resuscitation - Utilization of CCATT to Transport and Stabilize Critically Injured and Unstable Casualties.

Maddry J, Ball E, Cox D, Flarity K, Bebarta V

Introduction: The U.S. Air Force utilizes specialized Critical Care Air Transport Teams (CCATT) for transporting "stabilized" patients. Given the drawdown of military forces from various areas of operation, recent CCATT operations have increasingly involved the evacuation of unstable and incompletely resuscitated patients from far forward, austere locations. This brief report describes unique cases representative of the evolving CCATT mission and provides future direction for changes in doctrine and educational requirements in preparation for en route combat casualty care.

Methods and Materials: This case series describes three patients who required significant resuscitation during CCATT transport from austere locations between April and November 2017. Approval for this project was received from the US Air Force 59th Medical Wing Institutional Review Board as non-research.

Results: Case 1: CCATT was dispatched to transport patient 1 who was reported to have a head injury after a fall. Upon evaluation of the patient onboard the aircraft, it was discovered that the patient was in cardiac arrest. Cardiopulmonary resuscitation was performed during tactical takeoff with frequent combat maneuvers. The patient developed a palpable pulse after three rounds of CPR, three doses of epinephrine, and one unit of packed red blood cells. Point of care laboratory analysis demonstrated a profoundly elevated lactate level. Cyanide poisoning was a concern but there was no antidote available in the available equipment set. After delivery to a medical facility, blood samples were positive for cyanide. Over the next 2 weeks, the patient improved and was discharged home, neurologically intact. Case 2: Patient 2 sustained complex blast injuries and bilateral lower extremity amputations. He required early transport for continuous renal replacement therapy (CRRT). The patient received 200 units of blood products in the 24 hours prior to transport and developed renal failure, pulmonary edema, and elevated ICP. During the 7 hour flight, Patient 2 received frequent adjustments of vasopressor medications, multiple Dakins solution soaks and flushes, and 1 unit of fresh frozen plasma. He remained alive 2 months later. Case 3: The team was notified to collect an urgent patient with a blast lung injury and bilateral lower extremity amputations. The ground team encountered difficulty ventilating the patient. Patient 3 arrived in the back of a pickup truck accompanied by medics and being bag valve mask ventilated with a pulse oximetry reading of 65%. He was secured to the floor of the aircraft which departed within 5 minutes of arrival. An ultrasound of the lungs showed no pneumothorax. By the end of the flight, the patient's oxygen saturation had risen to 95% and he was delivered to the emergency department in stable condition. He later passed away in the operating room due to severe blast lung and cardiac contusion.

Conclusion: This brief report demonstrates the need of CCATT in the transport of unstable patients from forward deployed locations. The Air Force has adapted and is continuing to adapt CCATT training, equipment, onboard diagnostics and therapies, and team members' clinical skills to meet en route care combat casualty needs.

J Trauma Acute Care Surg. 2019 Jan;Epub ahead of print

# Hypobaria during long-range flight resulted in significantly increased histopathological evidence of lung and brain damage in a swine model.

Scultetus A, Jefferson M, Haque A, Ho L, Hazzard B, Saha B, Chun S, Auker C, Moon-Massat P, McCarron R, Malone D

BACKGROUND: Aeromedical evacuation to definitive care is standard in current military conflicts. However, there is minimal knowledge on the effects of hypobaria (HYPO) on either the flight crew or patients. The effects of HYPO were investigated using healthy swine.

METHODS: Anesthetized Yorkshire swine underwent a simulated 4 h "transport" to an altitude of 2,441 m (8,000 feet.; HYPO, N = 6) or at normobaric conditions (NORMO, N = 6). Physiologic and biochemical data were collected. Organ damage was assessed for hemorrhage, inflammation, edema, necrosis, and for lungs only, microatelectasis.

RESULTS: All parameters were similar prior to and after "transport" with no significant effects of HYPO on hemodynamic, neurologic, or oxygen transport parameters, nor on blood gas, chemistry, or complete blood count data. However, the overall Lung Injury Score was significantly worse in the HYPO than the NORMO group (10.78 ± 1.22 vs. 2.31 ± 0.71, respectively) with more edema/fibrin/hemorrhage in the subpleural, interlobular and alveolar space, more congestion in alveolar septa, and evidence of microatelectasis (vs. no microatelectasis in the NORMO group). There was also increased severity of pulmonary neutrophilic (1.69 ± 0.20 vs. 0.19 ± 0.13) and histiocytic inflammation (1.83 ± 0.23 vs. 0.47 ± 0.17) for HYPO versus NORMO, respectively. On the other hand, there was increased renal inflammation in NORMO compared with HYPO (1.00 ± 0.13 vs. 0.33 ± 0.17, respectively). There were no histopathological differences in brain (whole or individual regions), liver, pancreas, or adrenals.

CONCLUSION: Hypobaria, itself, may have an adverse effect on the respiratory system, even in healthy individuals, and this may be superimposed on combat casualties where there may be preexisting lung injury. The additional effects of anesthesia and controlled ventilation on these results are unknown, and further studies are indicated using awake models to better characterize the mechanisms for this pathology and the factors that influence its severity.

Injury. 2019 Feb;50(2):358-364

# Specific stretchers enhance rapid extraction by tactical medical support teams in mass casualty incidents.

Service Medical du Raid, Reuter P, Baker C, Loeb T

OBJECTIVE: In mass casualty incidents where the threat is on-going, victim evacuation remains a challenge: fast extraction while respecting spinal immobilisation and haemorrhage control. Different devices can be used but their suitability has not been compared.

METHODS: We conducted a simulation study comparing eight extraction devices with a randomisation of the order of testing. Five teams, consisting of four officers, evacuated a single victim in five steps: device's deployment, loading the victim, carrying the victim along a corridor, negotiating a corner passage and a descent by staircase. Primary outcome was the emergency extraction time, from deployment to the first obstacle. Secondary outcomes included ease of transport and victim's stability, rated from 1 (worst) to 10 (best).

RESULTS: One hundred and sixty simulations were carried out. The median emergency extraction time was 16.7 [IQR: 11.6-24.9] seconds. The three speediest devices were the "firefighters' worn", "snogg" and "flexible tarp", taking 9.7 [8.1-11.0], 11.7 [10.9-15.4] and 12.2 [11.2-17.9] seconds respectively (p < 0.0001). Regarding the ease of transport, the three best-evaluated devices were the "firefighters' worn", "strap" and "flexible tarp" with 10 [9-10], 9 [8-9] and 8 [8-9] respectively (p < 0.0001). Considering stability reported by simulated victims, the three best-evaluated devices were the "inflated stretcher", "flexible tarp" and "firefighters' worn" with 8.0 [7.8-9.0], 8.0[7.0-8.0] and 6.5 [6.0-7.0] respectively.

CONCLUSION: Devices were not equivalent in terms of extraction time and suitability criteria. For rapid extraction of victims from danger zones, the "firefighter's worn" and "flexible tarp", as very simple stretchers, seem to be the most appropriate devices.

J Spec Oper Med. Spring 2019;19(1):48-51.

# Improvised Ground Evacuation Platforms for Austere Special Operations Casualty Transport.

Antosh I, McGrane O, Capan E, Dominguez J, Hofmann L

There are no established ground medical-evacuation systems within Special Operations Command Africa (SOCAFRICA), given the austere and varied environments. Transporting the injured casualty requires ingenuity and modification of existing vehicles. The Expeditionary Resuscitative Surgical Team (ERST) assigned to SOCAFRICA used four unconventional means for ground evacuation. This is a retrospective review of the various modes of ground transportation used by the ERST-3 during deployment with SOCAFRICA. All handcarried litter and air evacuation platforms were excluded. Over 9 months, four different ground casualty platforms were used after they were modified: (1) Mine-Resistant Ambush-Protected All-Terrain Vehicle (MAT-V; Oshkosh Defense); (2) MRZR-4 ("Razor"; Polaris Industries); (3) nonstandard tactical vehicles, (NSTVs; Toyota HiLux); and (4) John Deere TH 6x4 ("Gator"). Use of all vehicle platforms was initially rehearsed and then they were used on missions for transport of casualties. Each of the four methods of ground evacuation includes a description of the talon litter setup, the necessary modifications, the litter capacity, the strengths and weaknesses, and any summary recommendations for that platform. Understanding and planning for ground casualty evacuation is necessary in the austere environment. Although each modified vehicle was used successfully to transfer the combat casualty with an ERST team member, consideration should be given to acquisition of the MAT-V medical-specific vehicle. Understanding the currently available modes of ground casualty evacuation transport promotes successful transfer of the battlefield casualty to the next echelon of care.

J Trauma Acute Care Surg. 2019;Epub ahead of print

# Helicopter MEDEVAC in the Korean War: Did it Matter?

Barr J, Montgomery S

BACKGROUND: Due to M*A*S*H and other popular portrayals, helicopter evacuation of casualties has been closely linked to the Korean War. We sought to investigate their role in military medicine during this conflict.

MATERIALS AND METHODS: This study incorporated a thorough review of the original source documents dating to the Korean War that are housed in the National Archives, the Military History Institute, and other repositories.

RESULTS: Medical evacuation helicopters entered the war late, after the United Nations forces had suffered the majority of their casualties. There were relatively few helicopters in the country, and a combination of mechanical and personnel issues kept many grounded. Technological constraints limited their efficacy. Military policy forbade rescues from the front lines, and inter-hospital transfers comprised a significant percentage of their missions.

CONCLUSIONS: Helicopters did not appreciably decrease the average time from wounding to surgical care, nor did they evacuate a statistically significant number of casualties, and ultimately they had minimal effect on military medicine. However, the war did provide helicopters the opportunity to prove themselves conceptually, leading to their widespread usage in Vietnam, in later conflicts, and ultimately in civilian health care systems.

STUDY TYPE: Historical Reflection

LEVEL OF EVIDENCE: Not applicable.

J Trauma Acute Care Surg. 2019;Epub ahead of print

# The Promising Future of Drones in Prehospital Medical Care and its Application to Battlefield Medicine.

Braun J, Gertz S, Furer A, Bader T, Frenkel H, Chen J, Glassberg E, Nachman D

Unmanned aerial vehicles (UAV), commonly referred to as drones, have been made widely available in recent years leading to an exponential growth in their roles and applications. The rapidly developing field of medical drones is on the verge of revolutionizing pre-hospital medicine enabling advanced healthcare delivery to once-inaccessible patients. The aim of this review is to clarify the basic technical properties of currently available medical drones and review recent advances and their usefulness in military and civilian healthcare missions. A thorough search was conducted using conventional medical literature databases and non-medical popular search engines. The results indicate increasingly rapid incorporation of UAVs into search and rescue missions, telemedicine assignments, medical supply routes, public health surveillance and disaster management. Medical drones appear to be of great benefit for improving survivability of deployed forces on and off the battlefield. The emerging aerial medical delivery systems appear to provide particularly promising solutions for bridging some of the many serious gaps between third world healthcare systems and their western counterparts and between major metropolitan centers and distant rural communities. The global nature of drone-based health-care delivery needs points to a need for an international effort between collaborating civilian and military medical forces in order to harness the currently available resources and novel emerging technologies for broader life-saving capabilities.

Study type: Review label of evidence: V.

Mil Med. 2019 Jul 1;184(7-8):e225-e229

# A Descriptive Analysis of Causalities Undergoing CASEVAC from the Point-of-Injury in the Department of Defense Trauma Registry.

Schauer S, Naylor J, Bellamy M, Maddry J, April M

J, April M

INTRODUCTION: The recent conflicts in Iraq and Afghanistan entail an asymmetric battlefield without clearly defined forward lines of troops as seen in previous wars. Accordingly, the United States military medical services have increasingly adopted casualty evacuation (CASEVAC) platforms. We describe CASEVAC events reported within the Department of Defense Trauma Registry (DODTR).

MATERIALS AND METHODS: This is a secondary analysis of previously published data from two datasets spanning from 2007 through 2017. We isolated casualties within our dataset that had a documented evacuation method from the point-of-injury other than dedicated medical evacuation platforms (e.g., MEDEVAC, etc.).

RESULTS: During OPERATION IRAQI FREEDOM, three casualties underwent CASEVAC. The median age was 30 and all were male. Most sustained injuries from explosives (67%) and the median composite injury scores were low (10). The most frequent seriously injured body region was the thorax (67%). All survived to hospital discharge. During operations in Afghanistan (OPERATION ENDURING FREEDOM, OPERATION FREEDOMS SENTINEL, OPERATION NEW DAWN), 248 casualties underwent CASEVAC. The median age was 28 and most (96%) were male. Most sustained injuries from explosives (58%) and the median injury score was low (9). The most frequent seriously injured body region was the extremities (24%). Most (97%) survived to hospital discharge. During OPERATION INHERENT RESOLVE, 247 casualties underwent CASEVAC. The median age was 21 and most (96%) were male. The majority sustained injuries from explosives (61%) and the median injury score was low (9). The most frequent seriously injury body region was the extremities (27%). Most survived to hospital discharge (94%).

CONCLUSIONS: In our dataset, CASEVAC events most frequently involved US military personnel service members with most surviving to hospital discharge. Developing new terminology that distinguishes different types of CASEVAC would allow for more accurate future analyses of casualty evacuation and outcomes - such as those transports that are truly in a non-medical versus the various medical platforms that do not fall with into the confines of the MEDEVAC platforms.

Mil Med. 2019 Jul 23;Epub ahead of print

# Influence of Time to Transport to a Higher Level Facility on the Clinical Outcomes of US Combat Casualties with TBI: A Multicenter 7-Year Study.

Maddry J, Arana A, Perez C, Medellin K, Paciocco J, Mora A, Holder W, Davis W, Herson P, Bebarta V

INTRODUCTION: Traumatic brain injury (TBI) is a leading cause of death and disability worldwide and is associated with mortality rates as high as 30%. Patients with TBI are at high risk for secondary injury and need to be transported to definitive care expeditiously. However, the physiologic effects of aeromedical evacuation are not well understood and may compound these risks. Combat TBI patients may benefit from delayed aeromedical evacuation. The goal of this study was to evaluate the impact of transport timing out of theater via Critical Care Air Transport Teams (CCATT) to a higher level facility on the clinical outcomes of combat casualties with TBI.

MATERIALS AND METHODS: We performed a retrospective review of patients with TBI who were evacuated out of theater by CCATT from January 2007 to May 2014. Data abstractors collected flight information, vital signs, procedures, in-flight assessments, and outcomes. Time to transport was defined as the time from injury to CCATT evacuation out of combat theater. We calculated descriptive statistics and constructed regression models to determine the association between time to transport and clinical outcomes. This study was approved by the U.S. Air Force 59th Medical Wing Institutional Review Board.

RESULTS: We analyzed the records of 438 patients evacuated out of theater via CCATT and categorized them into three groups: patients who were transported in one day or less (n = 165), two days (n = 163), and three or more days (n = 110). We used logistic regression models to compare outcomes among patients who were evacuated in two days or three or more days to those who were transported within one day while adjusting for demographics, injury severity, and injury type. Patients who were evacuated in two days or three or more days had 50% lower odds of being discharged on a ventilator and were twice as likely to return to duty or be discharged home than those who were evacuated within one day. Additionally, patients transported in three or more days were 70% less likely to be ventilated at discharge with a GCS of 8 or lower and had 30% lower odds of mortality than those transported within one day.

CONCLUSIONS: In patients with moderate to severe TBI, a delay in aeromedical evacuation out of the combat theater was associated with improved mortality rates and a higher likelihood of discharge to home and return to duty dispositions. This study is correlational in nature and focused on CCATT transports from Role III to Role IV facilities; as such, care must be taken in interpreting our findings and future studies are needed to establish a causal link between delayed evacuation and improved discharge disposition. Our study suggests that delaying aeromedical evacuation of TBI patients when feasible may confer benefit.