Long−Distance Aeromedical Transport of Patients with COVID−19 in Fixed−Wing Air Ambulance Using a Portable Isolation Unit: Opportunities, Limitations and Mitigation Strategies

Figures & data

Figure 1 EpiShuttle PMIU in a Bombardier Challenger 604 Air Ambulance Jet. Panel (A) Loading/Unloading of the EpiShuttle PMIU. Panel (B) The EpiShuttle PMIU in the Cabin of the Challenger 604. Panel (C) Equipment “Rack” at the Head End of the EpiShuttle PMIU and “Saddle” to prevent disconnection of lines, ventilation tubes and monitoring during loading and unloading.

Box 1 Checklist PMIU Preparation Prior to Patient Loading

The Following Equipment is Stored Inside the PMIU
Ventilation bag and oropharyngeal airway.
Pillow and blanket.
Water bottle.
Suction catheters, suction tube (tubing threaded through the wireport to the outside of the PMIU, closed with a clamp outside the PMIU while not in use).
Oxygen Mask with tubing (tubing threaded through the wireport to the outside of the PMIU, closed with a clamp outside the PMIU while not in use).
All monitoring cables (ECG, NIBP, SaO2, Temp, etCO2; threaded through the wireport to the outside of the PMIU).
At least three infusion lines, filled with normal saline, with a 3−way stopcock at each end, threaded through the wireport to the outside of the PMIU.
If patient ventilated, preparation of the ventilator sleeve ventilator hose and fixation of the HEPA filter that connects the ventilation hose on the clean side and the ET tube, mask or other patient respiratory device inside the PMIU.
If patient ventilated, cuff pressure monitoring line (tubing threaded through the wireport to the outside of the PMIU, closed with a clamp outside the PMIU while not in use).

Box 2 Checklist PMIU Patient Preparation

Max. weight 110 kg, max. width (at hips) 50 cm, height 140–195 cm
Written informed consent re transport risks in a PMIU and possible need for sedation.
At least two peripheral iv cannulas (well secured and patent), or one multi−lumen CVC.
Arterial cannula in all patients with circulatory instability (well secured and patent).
In intubated patients: documented endotracheal tube position and thorough fixation of the tube.
Bladder catheter in all flights longer than 3 hours.
Bowel prep with laxatives on the day prior to transport, diapers and nil by mouth on the day of transport.
No rings, jewelry and watches.

Table 1 Patient and Transport Characteristics

Patient No.	1	2	3	4	5	6	7	8	9	10	11	12	13
Transport from/to	Egypt/Germany*	Spain/Sweden	Spain/Sweden	Comoro Islands/Switzerland	Sao Tome/Switzerland	Afghanistan/Belgium	Afghanistan/United Kingdom	Afghanistan/Germany	Afghanistan/Germany	Afghanistan/Germany	Afghanistan/Bulgaria	Kosovo/Sweden	Turkmenistan/France
Reason for transportation	Holidaymaker. Transfer to higher level of care in home country.	Holidaymaker. Transfer to home country.	Holidaymaker. Transfer to home country.	Expatriate. Transfer to higher level of care.	Expatriate. Transfer to higher level of care.	Expatriate. Transfer to higher level of care in home country.	Expatriate. Transfer to higher level of care in home country.	Expatriate. Transfer to higher level of care.	Expatriate. Transfer to higher level of care.	Expatriate. Transfer to higher level of care.	Expatriate. Transfer to higher level of care.	Holidaymaker. Transfer to higher level of care in home country.	Expatriate. Transfer to higher level of care in home country.
Transport Distance (km)	(planned) 3,406	2,346	2,182	7,412	5,097	5395	5673	5117	5117	5117	4023	1563	5102
Transport time (HH: MM)	(planned) 05:15	03:00	03:15	11:10	06:00	09:00	09:00	08:00	08:30	08:30	05:45	02:15	08:00
Fuel stops	(planned) 0	0	0	1	0	1	1	1	1	1	0	0	1
Cabin pressure	(planned) sea level	Standard	Sea level	Standard	Standard	Standard	Standard	Standard	Standard	Standard	Standard	Standard	Standard
Takeover at	n.a.	Airport	Airport	Airport	Airport	Airport	Airport	Airport	Airport	Airport	Airport	Hospital	Airport
Handover at	n.a.	Airport	Airport	Airport	Hospital	Airport	Airport	Hospital	Hospital	Hospital	Airport	Hospital	Hospital
Gender/age (years)	M/62	F/76	M/80	F/58	M/46	M/51	M/50	M/49	M/48	M/55	M/47	M/57	M/49
COVID−19 diagnosis	PCR confirmed	PCR confirmed	PCR confirmed	PCR confirmed	Clinically suspected	Clinically suspected	PCR confirmed	PCR confirmed	PCR confirmed	PCR confirmed	PCR confirmed	PCR confirmed	Clinically suspected
Ventilated	y	n	y	n	n	n	n	y	n	n	n	n	n
Oxygen requirement prior to transport	FiO2 0.6	Nil	FiO2 0.4	5 L/min via face mask	Nil	4 L/min via face mask	4 L/min via face mask	15 L/min face mask, intubation at the airport	Nil	2 L/min via face mask	Nil	6 L/min via face mask	9 L/min via face mask
Oxygen requirement en−route	n.a.	4 L/min via face mask	FiO2 0.8	4 L/min via face mask	2 L/min via face mask	6 L/min via face mask	4 L/min via face mask	FiO2 0.65	2 L/min via face mask	5 L/min via face mask	4 L/min via face mask	6 L/min via face mask	6 L/min via face mask
Inotropes	y	n	y	n	n	n	n	y	n	n	n	n	n
Sedation	n.a.	Midazolam, Fentanyl	Midazolam, Fentanyl	Lorazepam	Lorazepam	Morphine	Lorazepam, Midazolam	Midazolam, Propofol	Lorazepam, Midazolam	Lorazepam, Propofol	Lorazepam, Midazolam	Midazolam	None
Outcome	n.a.	Excellent	ET tube movement one−sided intubation hypercapnia respiratory acidosis	Excellent	Excellent	Excellent	Excellent	Excellent	Excellent	Excellent	Excellent	Excellent	Excellent

Note: *Patient not released from hospital, mission aborted.

Abbreviations: km, kilometer; HH, hours (two digits); MM, minutes (two digits); n.a, not applicable; y, yes; n, no; M, male; F, female; PCR, polymerase chain reaction; FiO₂, fraction of inspired oxygen.

Table 2 Main Challenges Identified During PMIU Transports and Mitigation Strategies

Problem/Risk Identified	Mitigation Strategy
Lengthy preparation of the PMIU prior to loading the patient.	Development of a dedicated checklist (Box 1), Preparation of the PMIU with all lines, tubes and cables on the outward sector of the mission prior to arrival at the takeover point.
Complex preparation of the patient prior to closing and disinfecting the PMIU.	Development of a dedicated Checklist (Box 2). Call with the referring hospital to ensure patient is adequately prepared, with sending the respective checklist by fax/email, if possible.
Heavy weight and high center of gravity of the PMIU while loading and unloading.	All transports conducted with three MedCrew and two or three FlightCrew to ensure sufficient personnel is available to load and unload the PMIU. Note that ground ambulance crews transporting the patient to the airport in PPE without the use of a PMIU have to be considered “contaminated” and cannot assist in loading.
Risk of line and tube dislodgement as a result of de−synchronized movement of ventilator, infusion pumps, monitor and the PMIU while loading and unloading.	Development of a rack to fix vital equipment as ventilator, syringe drivers and monitor the head end of the PMIU during loading and unloading (see Figure 1).
Limited visibility, environmental heat and noise while in full PPE during Airport Tarmac takeover and handover.	Takeover and handover of critically ill patients in the hospital (bed−to−bed transport in the PMIU), if permission for the MedCrew to leave the airport and enter the country can be obtained.
Reduced manual dexterity when delivering care through the porthole gloves.	Meticulous preparation of the patient prior to closing and disinfecting the PMIU (refer to Checklist Patient Preparation, Box 2).
Inability to auscultate to diagnose ET tube displacement and pneumothorax.	Use of Bluetooth microphones to transfer breath sounds, such as Stemoscope (Hulu Devices, San Diego, CA, USA) and Bluetooth enabled electronic stethoscopes such as the Littmann Electronic Stethoscope 3200 (3M™ Littmann^®, St. Paul, MN, USA). Use of cordless ultrasound scanners inside the PMIU for lung and other ultrasound investigations (eg, Clarius C3 HD, Clarius, Burnaby BC, Canada).
Suction unit without HEPA filter for exhaust air.	Fixing a HEPA filter to the suction unit air exhaust, change of that filter after each transport.
Unintentional pull on monitor cables and infusion lines can move contaminated cable/tubing sections from inside the PMIU to outside of the PMIU.	All monitor cables, infusion lines, suction and oxygen tubing are secured with zip ties and/or tape inside the PMIU prior to closing and disinfecting the PMIU. All lines are clearly labeled inside and outside of the PMIU.
Very limited verbal communication with the patient inside the PMIU due to environmental noise in−flight.	IPad (sealed in a pouch) to enable written communication with the MedCrew via the on−board WIFI hotspot. Alternatively pen and paper fixed with a line and suction cup to the inside of the canopy close to the patient's head.
Anxiety and claustrophobia of the patient inside the PMIU.	Carefully educating the patient/relatives about the risks, benefits, and alternatives of a PMIU transport with written informed consent prior to the transport. Sedation with oral lorazepam or alternative oral or intravenous medications.