CASE STUDY: Breaking the limits on long range medical transports
Dr Víctor Cervantes, Medical Director of Jet Rescue Air Ambulance, and Carlos Salinas, CEO, outline a world-record long-range aeromedical transport of an ECMO-supported patient from Mexico to South Korea
A world-record aeromedical transfer of a patient on extracorporeal membrane oxygenation (ECMO) therapy was performed on 4 June 2020 by Jet Rescue Air Ambulance, onboard a Learjet 36, from Christus Muguerza Hospital in Monterrey, Mexico, to Asan Hospital in Seoul, South Korea.
A 55-year-old South Korean citizen, who developed severe acute respiratory distress syndrome due to irreversible damage caused by Covid-19, was placed in venovenous (VV) ECMO support as a bridge to lung transplantation. The patient’s expat insurance determined that he would be repatriated onboard an air ambulance due to extreme acuity of medical condition, with a goal of safe admission to Asan Hospital in Seoul for lung transplantation. Jet Rescue’s mobile ECMO team was activated, including a perfusionist, an ECMO specialist cardiopulmonary physician, and Dr Victor Cervantes, the company’s Medical Director.
Pre-transport planning
The medical team was briefed about Extracorporeal Life Support Organisation guidelines for secondary ECMO transport as the CEO approved the medical logistics plan and aviation platform for the mission. Due to scheduled maintenance, the company was unable to use its larger Learjet 60 so the reliable Learjet 36 was selected for the mission. Fuel stops were selected based on locations that have nearby tertiary hospitals, and FBOs (ground services) were alerted to have their oxygen refilling vendors on-site for recharging the aircraft’s oxygen supply
To ensure failsafe power supply for the medical equipment, an auxiliary power source was brought onboard. In addition to 2M oxygen tanks (full at 2000psi) as the main oxygen resource, the team also loaded multiple portable oxygen tanks as emergency backups. All medical supplies (including oxygen) were calculated using the following formula: X= actual dose per hour * total transport time * 1.5 (safety factor). A margin of 50 per cent more oxygen, 50 per cent more medication and 50 per cent additional medical supplies, including blood plasma products, was used as an added measure of safety.
In adherence to flight crew duty time limits, the mission required two sets of aviation teams (two pilots and two co-pilots). One team was flown in advance to Alaska to replace the original crew that flew the aircraft from Mexico. Given the medical complexity, a telemedical consultation link was established in advance with the medical team at the referring hospital. The telecom platform consisted of Garmin GPS Messaging System and hands-free satellite phone with personalised access for all team members via their smart phone. The flight doctor in charge was also directed to send continuous clinical updates to Jet Rescue mission control. Total transport time, from bedside to bedside with an estimated one-hour ground time during each fuel stop, was 22 hours.
Patient transfer
On the day of the transport, the patient was on VV ECMO (jugular and femoral canulae), partial sedation (RASS -2) with propofol, fentanyl and dexmedetomidine, tracheostomy and mechanical ventilation (PEEP 10cm H2, driving pressure on 15cm H2O, tidal volume within 2-3ml/ kg cSTAT (static compliance 7ml/cm H2O), norepinephrine at 0.7mcg/kg/min, anticoagulation with unfractionated heparin controlled with anti Xa activity). Infusion pumps for IV drips and medications, as well as portable mechanical ventilator were connected; the gas blender was disconnected, and ECMO sweep-gas was maintained with 100 per cent FiO2. The heat exchanger was disconnected during ground transportation and connected during air-transport.
The patient developed fever in-flight, which was managed with acetaminophen, cold compresses around cannulas, and a heat exchanger was set to maintain normal temperature. During takeoff, the patient needed an increase in vasopressors to maintain MAP over 65mmHg, and colloids (albumin) was used to increase intravascular volume. Ketamine was used to lower propofol dose and improve hemodynamics, ACT test was done every six hours to control unfractionated heparin dose, four-gas analysis was taken during the entire transportation.
After landing in South Korea and clearing airport arrival procedure, the patient was transported by ground ambulance to the hospital. A 35-minute drive capped the 22-hour mission. The patient was handed over, in a stable condition, to the ICU ECMO team that was waiting at Asan hospital in Seoul.
Jet Rescue specialises in complex and long-distance transportation and is the most experienced AA provider in performing ECMO flights in the Americas. Joint medical planning of the case was instrumental for the team’s ability to transport the patient safely; the partnership and expertise in both areas of ECMO and air medical transport was an important factor to successfully transport this patient.