Ground emergency medical services and HEMS are part of the medical chain in the care of patients with COVID-19. Due to the pandemic, they are faced with new challenges, and different countries and health care systems vary in their reactions to the problem. Our study’s data demonstrate that, although care and transport of COVID-19 patients may be handled in different ways in different European countries, it is nevertheless safe. As the number of patients with COVID-19 could increase, however, aeromedical crews must be able to adapt.
Preparation of COVID-19 missions
All participating air ambulance providers developed special procedures and safety instructions to be followed when transferring COVID-19 patients, including equipping the aircrafts with full PPE, and training their crews in its proper use. This and the training of crews in how to deal with COVID-19 patients could have contributed to the fact that no COVID-19 infections were reported in crew members flying these missions.
Mode of transport
At present, ground transport of COVID-19 patients seems to be the preferred mode of transport when caring for patients in a primary mission. This data is in line with recommendations across Europe (7). On the contrary, for interfacility transport, air is the preferred mode. Both strategies have advantages and disadvantages. Finding the balance between ground and air transport is a challenge for the HEMS crews.
In a primary mission for a noncritical patient who needs further medical treatment in a hospital, transport by ground ambulance without physician attendance is practical, safe and resource sparing. In the case of critically ill patients, the HEMS team has to decide whether an HEMS physician should accompany the patient and which mode of transport is most useful, taking into account the distance to the hospital, possible changes of equipment, potential deterioration of the patient during transport, and the need for final disinfection. After air transport of a COVID-19 patient, the aircraft is out of service until the final disinfection.
Patients in critical condition who are being transferred to a higher-level care facility may need medical interventions en route. Air transport is the logical method in many of these cases. Data in the literature show that patients who are transferred using expedited helicopter transfer protocols have better post-transfer survival (8).
In some countries, HEMS transport of COVID-19 patients is avoided, with the SAR service of the armed forces being in charge instead. Denmark, for example, like many other European countries, has a tight network of ground-based pre-hospital critical care services, and rapid-response vehicles are staffed with consultant anaesthetists and paramedics. Most COVID-19 patients in Denmark were transported by these services in collaboration with the local EMS. Patients from islands not attached to the Danish mainland who are suspected of having or confirmed to have COVID-19 are as a rule transported in the Merlin 101 search and rescue (SAR) helicopters. These are operated by the Danish Air Force, with critical care capabilities provided by physician-paramedic teams from the Central Denmark Region. These teams are using the EpiShuttle® to isolate patients during transport.
Cooperation among countries
In some countries, the number of serious cases was beyond what the health system could accommodate while still maintaining high European standards of care. Accordingly, some serious cases were transported to neighbouring European countries with additional intensive care capacity. Long-distance transport was primarily performed by fixed-wing aircraft, as was repatriation of European inhabitants from overseas.
Medical interventions
Many medical interventions increase the risk of virus transmission (5, 9-11). Examples are non-invasive ventilation (NIV), airway management, CPR, or even recording an electrocardiogram (ECG) (11-13). Similar to SARS-CoV-1 patients, there are some COVID-19 patients who are “superspreaders” with a very high transmission rate (11). Therefore, it is of utmost importance to equip the EMS and HEMS with PPE to wear when taking care of patients with suspected or confirmed COVID-19. Modern air ambulance services are able to provide advanced interventions during transport, including intensive care procedures, differentiated catecholamine therapy, volume resuscitation, modern ventilation strategies, ECMO, inhaled nitric oxide, or even the use of heart-assisted devices (e.g. like Impella®) during transport (14-17). Several guidelines recommend the use of ECMO or inhaled nitric oxide in selected COVID-19 patients. Some patients may deteriorate quickly and need ECMO during transport (Table 2) (18-20).
Fluid therapy and drug administration are common in emergency medicine and intensive care, and are performed in COVID-19 patients as well. Surprisingly, the use of lung ultrasound in the pre-hospital setting is very limited, although it could help diagnose emergency patients with dyspnoea. Portable point-of-care ultrasound (POCUS) is a safe and effective bedside pre-hospital tool which can be used for initial evaluation and management in patients with confirmed or suspected COVID-19 infection (21). The data of our survey show that even in modern, well-equipped European air ambulance systems with highly trained specialists, the potential for improvement in pre-hospital POCUS exists.
Infection status and hygiene
Due to lack of information on infection status and limited resources and space, the risk of virus transmission in a helicopter or airplane is possibly higher than for in-hospital healthcare providers. Furthermore, many medical interventions carried out in emergency situations, such as airway management and suctioning, are associated with a high risk of contamination. Appropriate PPE is therefore recommended for EMS clinicians when approaching patients suspected of having COIVD-19 (22). If information about potential COVID-19 has not been provided, initial assessment, if possible, should begin from a distance of at least 2 metres from the patient (22). During medical care, a facemask should be worn by the patient, and if transport is necessary, the number of healthcare providers in the patient compartment should be limited to a minimal number (22). PPE should be matched to the potential mode of viral transmission, including contact (gloves, apron), droplet (gloves, apron, eye protection, FFP 2/N95 mask), or airborne (gloves, fluid-repelling long-sleeved gown, eye protection, FFP 3 mask) (22-24).
Interfacility transport missions can be very exhausting and physically stressful for the medical team. They often involve several hours of work in full PPE, conditions which may contribute to medical errors (25).
COVID-19 patients are increasingly being transferred in fixed-wing aircraft and helicopters containing patient isolation units (PIUs) like the EpiShuttle® or the Rega PIU. The Epishuttle® is a CE 1789 compliant reusable single-patient isolation and transport system that can be used in ambulances, helicopters and airplanes. The shuttle can either be used to protect the surroundings from an infectious patient or to protect the patient from the surroundings. During transport, the medical crew does not need to wear full personal protective equipment. The EpiShuttle® is equipped with different ports (operator ports, wire port, ventilator port) and a ventilation system that generates more than 15 air exchanges per hour and can be used with negative or positive pressure inside, depending on who needs to be protected (the patient or the crew).
The Rega PIU comprises a flexible safety hull stabilised by arched wires mounted on a hard floor plate. It is maintained under negative pressure by a high-efficiency particulate air filtered ventilation system that uses aircraft power and/or battery power. The PIU barrier performance has proven equal to that provided by protective clothing. Its fixation system allows transportation on any commonly available patient stretcher. The PIU is designed to fit in a fixed-wing ambulance, a medium-sized helicopter, and ground-based ambulances (7).
As a result of the effective protection of the HEMS crew during transport of SARS-CoV-2 patients, helicopters do not have to be disinfected after patient transport if a PIU is used. Accordingly, the aircraft can remain in operation longer.
Limitations of the study
Our study has some limitations. First, it presents a selection of European HEMS providers, and cannot be generalized for all European air ambulance services. Second, not all invited providers were able to report COVID-19 patients’ mission-related data because COVID-19 patients were transported by the SAR service of the armed forces in their country. Third, European countries with a very high incidence of COVID-19, like Italy and Spain, did not participate in this study. Nevertheless, this study clearly shows that safe care during long transport of COVID-19 patients is achievable.