Background In a military setting, pre-hospital times may be extended due to geographical or operational issues. Helicopter casevac enables patients to be transported expediently across all terrains. The skill-mix of the pre-hospital team can vary.
Aim To quantify the doctors' contribution to the Medical Emergency Response Team–Enhanced (MERT-E).
Methods A prospective log of missions recorded urgency category, patient nationality, mechanism of injury, medical interventions and whether, in the crew's opinion, the presence of the doctor made a positive contribution.
Results Between July and November 2008, MERT-E flew 324 missions for 429 patients. 56% of patients carried were local nationals, 35% were UK forces. 22% of patients were T1, 52% were T2, 21.5% were T3 and 4% were dead. 48% patients had blast injuries, 25% had gunshot wounds, 6 patients had been exposed to blast and gunshot wounds. Median time from take-off to ED arrival was 44 min. A doctor flew on 88% of missions. It was thought that a doctor's presence was not clinically beneficial in 77% of missions. There were 62 recorded physician's interventions: the most common intervention was rapid sequence induction (45%); other interventions included provision of analgesia, sedation or blood products (34%), chest drain or thoracostomy (5%), and pronouncing life extinct (6%).
Conclusion MERT-E is a high value asset which makes an important contribution to patient care. A relatively small proportion of missions require interventions beyond the capability of well-trained military paramedics; the indirect benefits of a physician are more difficult to quantify.
- Pre-hospital care
- war injury
- helicopter retrieval
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In a military setting, pre-hospital times may be extended due to geographical or operational issues. Helicopter forward aeromedical evacuation (FdAE) enables wounded patients to be transported expediently across all terrains. Options exist in the type of helicopter deployed to evacuate wounded troops, and according to the air-frame, the skill-mix of the pre-hospital team can also vary. The current provision of helicopter FdAE provided by British Forces is the Medical Emergency Response Team–Enhanced (MERT-E), using a CH-47 Chinook helicopter (Boeing Defense, Space & Security). This study aimed to quantify the on-board doctors' contribution to the pre-hospital MERT-E mission.
MERT-E missions were entered into a contemporaneous log. Immediately after each mission, an urgency category was assigned to the mission and record made as to whether, in the crew's opinion, the presence of the doctor on board had made a positive contribution to patient care. Patient nationality, mechanism of injury, destination and medical interventions during the mission were also recorded.
Between July and November 2008, MERT flew 324 missions for 429 patients. Median number of patients carried was 1 (range 1–13). Of the 429 patients, 242 (56%) were local nationals, 150 (35%) were UK forces; 95 (22%) were T1, 223 (52%) were T2, 93 (21.5%) were T3 and 18 (4%) were dead. A total of 208 (48%) patients had blast injuries, 109 (25%) had gunshot wounds, and 6 had been exposed to blast and gunshot wounds. Forty-one patients (9.5%) were classified as medical, 23 (5%) received injuries in road traffic collisions and 42 patients had other diagnoses. Median time from take-off to ED arrival was 44 min (range 10–183). A doctor flew on 283/320 (88%) missions (not recorded in 4). It was thought that a doctor's presence was not clinically beneficial in 219/283 missions (77%). There were 62 recorded physician's interventions: the most common medical intervention was rapid sequence induction in 45% (28/62); other interventions included provision of analgesia, sedation or blood products (21/62), chest drain or thoracostomy (3/62), and pronouncing life extinct (4/62).
In mature civilian pre-hospital systems it has been shown that rapid transport to hospital (scoop and run) achieves improved outcomes compared to delaying transport to provide advanced life support interventions at the scene (stay and play).1 Military trauma differs from civilian trauma in many ways; the extreme nature of military wounding means that a hallmark of military injury is early lethality, with the accepted trimodal civilian distribution of death after trauma2 translating into a bimodal distribution of death3 4; a relatively high proportion of deaths occur early after injury.5 Early deaths typically have ‘injuries incompatible with life’; indeed, where coincidence has meant that the ‘front-line’ has been co-located with the medical services, such as in Beirut in the late 1980s, a significant proportion of these patients could still not be saved, despite evacuation timelines of just minutes.6
Pre-hospital rapid sequence induction and controlled ventilation have been shown to be of benefit in patients with thoracic injuries or decreased Glasgow Coma Scale.7 However, uncontrolled bleeding is the most common cause of potentially preventable battlefield death,8–10 and therefore expert early intervention will potentially save some patients who would otherwise succumb to exsanguination. Far forward surgical facilities require significant force-protection and logistic re-supply is a significant concern; even a single critically ill patient can rapidly exhaust a forward based surgical team's oxygen and blood supplies.4 In addition, contemporary counter-insurgency warfare, where there is no specific ‘front line’, also means that evacuation routes are increasingly exposed to the threat of attack, and ground options for casualty evacuation are limited.
In recent previous conflicts airframes have been routinely allocated to medical missions, but prior to 2006 there was no dedicated British helicopter FdAE system and many helicopter evacuations were ‘lifts of opportunity’.11 The optimal military pre-hospital solution would appear to be rapid helicopter FdAE with onboard skill mix availability to provide advanced life support skills en- route; this is encapsulated in the MERT-E concept, which has been in operation in southern Afghanistan since 2006. In current operations in Afghanistan, two casevac airframes are available: MERT-E, which routinely deploys with a doctor; and the US PEDROS helicopter casevac, staffed solely by paramedics.
Helicopters are high value assets, with respect to initial cost, maintenance and the personnel required to fly and maintain airworthiness. In addition, use as a casualty evacuation tool requires an airframe to remain ‘on-call’. When such a valuable asset is left on the tarmac, overstretched military logistical planners look enviously at its potential. For a helicopter to be afforded the protection of an ‘ambulance’ under the Geneva Conventions, it must permanently be marked up with red crosses as a medical asset.12 However, its value in the context of asymmetric warfare is less clear; there is little evidence to suggest that medical assets are targeted any differently by the insurgents.
Rapid helicopter evacuation can be achieved with or without the presence of a physician; while the Chinook airframe used is relatively large, ambient noise, difficulty in communication and rapid helicopter manoeuvring to avoid ground-to-air threats provides for a difficult working environment. Nevertheless, our data suggest that experienced practitioners can provide critical interventions; equipment can also be carried, including significant amounts of blood products. The optimum team mix for pre-hospital helicopter evacuation is hotly debated, with many studies demonstrating that, in a civilian context, the inclusion of a doctor versus another clinician (paramedic/nurse) appears to reduce mortality in the group attended by a physician.13–15 However, other groups have demonstrated no benefit for the addition of a physician over experienced nurses and paramedics.16 17
In this study, according to an immediate post-mission debrief by the team, the interventions a physician performed were perceived to add value (by crew consensus) to the pre-hospital medical mission in approximately one quarter of MERT-E missions in the contemporary coalition activity in southern Afghanistan.
Only a small proportion of the interventions performed would appear to be beyond the capability of well-trained military paramedics. However, we believe that the impact of a trained and experienced physician on-board lies beyond the immediate provision of technical skills, and includes leadership, triage and the application of judgement as to when and when not to intervene. Furthermore, the presence of doctors provides reassurance and leadership to other healthcare professionals as well as troops on the ground. This impact is more difficult to quantify than the direct result of the doctors' actions, and represents an important factor in the morale of the fighting troops as well as the MERT-E team.
MERT-E is a high value asset; considering that there are alternatives, optimal use will depend on ‘intelligent’ and flexible tasking by regional medical planners. It is of critical importance that this planning is contributed to by appropriate military medical practitioners.
Competing interests None.
Provenance and peer review Not commissioned; externally peer reviewed.
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