Infection control in air ambulance environments
Infection control in air ambulance environments.
Air ambulance services play a vital role in providing critical care to patients who require urgent medical attention in remote or inaccessible areas. However, the high-risk nature of transporting critically ill or injured patients in the confined space of an air ambulance presents a unique challenge in infection control. In this post, we will consider the importance of infection control in air ambulances and the measures that can be taken to minimise the risk of infection transmission.
The Importance of infection control in Air Ambulances
While COVID19 has become yesterday’s news to many (the WHO recently declared the Global Health Emergency over) it highlighted areas where mechanical infection control within air ambulances had not evolved to the degree required by a highly infectious airborne disease. This observation stems from the nature of the air ambulances environment itself. Unlike road ambulances, they are modified mutli-role platforms and not designed with the latest IP&C regulations at the centre of their DNA.
Clearly, mechanical or physical infection control is critical in air ambulance services as it ensures the safety of both the patient, and the crew. Patients who require air ambulance transportation are often vulnerable and have weakened immune systems, making them more susceptible to infections. The clinical crew faces a higher risk of exposure to infectious diseases, as they work alongside the patient in the confined space of the aircraft cabin. The flight crew are working within the same environment and in many cases cannot avoid patient contact (particularly on fixed wing – loading, securing doors, walking past the patient and unloading)
In such environments infection transmission is most likely to occur through direct contact with contaminated surfaces or via droplet transmission through coughing or sneezing, or airborne transmission through the inhalation of infectious particles. In the case of air ambulances, the risk of airborne transmission is higher due to the reduced cabin air volume but can be mitigated by air replacement cycles and HEPA filters (unfortunately most pressurised air ambulance aircraft use a single pressure ‘tube’ which does not allow for a pressure differential between the flight crew and the clinical area at the rear).
Measures to minimise the risk of infection transmission
Although mechanical infection control prevention in air ambulances is a primary goal various means can be taken to ensure the safety of both the patient and the medical crew, these being:
- Use of different points of ingress / egress. This prevents the flight crew from encountering the clinical team and patient. This feature, common to rotary assets and larger, unpressurised aircraft such as the Textron Sky Courier, is not common in pressurised turbo-props and light jets such as the Learjet 65 or Beechcraft King Air360. In the fixed-wing world, this places the Pilatus PC24 as the standout aircraft.
- Barriers between the flight deck and clinical area. A mechanical barrier between both compartments offers enhanced infection control measures. However this should be counter-balanced with enhanced safety considerations. During rotary NVIS Ops the rear clinical crew play an observation role and while voice commands can be relayed via the headset, the barrier may prevent useful non-verbal feedback and direct vision of rear crew through front-facing windows. Fixed wing aircraft may have sliding panel doors or curtains; however, both are designed for privacy and not for infection control measures.
- Air replacement and filtration. In most cases with both rotary and fixed wing air ambulances, air replacement durations are short (usually as a consequence of the original purpose of the aircraft rather than EMS considerations). Filtration may be added (be aware that this may require substantial modifications to an existing aircraft’s systems) to remove airborne contaminants with HEPA filters used to remove particles as small as 0.3 microns in diameter, including viruses and bacteria.
- Patient Isolation. Patients with suspected or confirmed infectious diseases can be transported in isolation units such as the EpiShuttle to minimise the risk of transmission. The isolation units typically have their own ventilation systems to prevent the spread of infectious particles. However, clinical considerations, such as the need for emergency access to the patient, may prevent their use and for some patient body sizes this type of solution is not practical.
- Personal Protective Equipment (PPE). Both the flight crew and medical team will be wearing appropriate PPE, including gloves, masks, gowns, and eye protection, to minimize the risk of exposure to infectious diseases. However, for the flight crew, the disrobing and robing of PPE away from the patient before flight and on landing, introduces logistic challenges in the small spaces afford to the flight crew. Facemasks may also cause difficulties in communication with air traffic services and other crew onboard the flight.
- Environmental Cleaning and Disinfection. The cabin and all medical equipment should be thoroughly cleaned and disinfected after each patient transport. This includes wiping down all surfaces with an appropriate disinfectant and ensuring that all medical equipment is properly sterilised. Space sanitisers such as the Zoono Germ Fogger may also be applied while the aircraft is on the ground awaiting the next mission.
- Training. The flight crew, ground and clinical crew should have a good understanding of the transmission risks and mitigations, each having delineated roles that are trained particularly in infection control measures, including the proper use of PPE, environmental cleaning and disinfection, and patient isolation.
It goes without saying that infection control is critical in air ambulance services to ensure the safety of the patient, the clinical crew and the flight crew. However, there are mechanical limitations.
These limitations are largely based on the aircraft available to perform these duties, the price point of these aircraft and the recognition that they are mutli-purpose platforms which are not specifically designed to operate to the same IP&C standards as road ambulances. While use of Part 21 J design services can modify aircraft to accommodate higher IP&C standards, it should be noted that in many cases the structure of the aircraft may not allow an optimal IP&C solution. And on to these limitations, you must further place aviation regulatory controls for egress, cabin pressure limitations, crash testing, load limits for air and electrical systems, weight, etc. Finally, there are commercial considerations in the cost of acquiring aircraft, subsequent modification and then its operation.
However, infection prevention and control is a dynamic vector. COVID-19 added new considerations for mechanical controls and improvements have consequently been made. It should be noted however, that the risk of infection transmission can be minimised but never be fully eliminated on air ambulance missions.