Pre-Hospital Airway Management & COVID 19

In this article Lara Hammond (KSS HEMS Paramedic) and Julian Wijesuriya (KSS HEMS Doctor) outline the implications of the COVID-19 pandemic for pre-hospital airway management. They discuss the pre-hospital use and challenges of PPE, modifications to scene & airway management and implications for patient conveyance.

Introduction:

In early December of 2019, a group of patients in Wuhan, China, presenting with pneumonia were reported to the WHO. One month later, the new coronavirus strain (SARS-CoV-2), which causes COVID-19, was sequenced. The disease rapidly spread and overwhelmed healthcare systems throughout the world.

Healthcare providers in all settings rapidly had to modify their management strategies and clinical pathways to adapt to the challenges presented by COVID-19. The challenges faced by pre-hospital teams undertaking advanced airway management are discussed here.

PPE

Risk Assessment:

The incubation period for COVID-19 is 1-14 days before symptoms show and clinical presentation varies widely from asymptomatic to life-threatening respiratory failure. Viral transmission is through respiratory droplets, aerosols or contaminated surfaces.

In the early phase of the pandemic, risk assessments regarding patient’s Covid-19 status were applied. However as transmissibility, incubation periods and asymptomatic infection rates were better understood, ambulance trusts recommended treating all patients as COVID-19 positive. As a result, Level 2 PPE became the minimum standard for all patient interactions, with level 3 PPE donned if an AGP (aerosol generating procedure) is in progress or anticipated.

Example specifications for Level 2 and Level 3 PPE.

Pre-hospital clinicians donning Level 3 PPE

Aerosol Generating Procedures:

Exactly what constitutes an AGP is debated and the subject of ongoing research. Examples of AGPs, as defined by different organisations relevant to prehospital practice, are outlined below:

List of AGPs by professional body / organisation

PPE vs Clinical Urgency:

It is inevitable from the list of AGPs that the sickest patients require pre-hospital clinicians to don the highest levels of PPE. Donning Level 3 PPE can be time-consuming and this presents a dilemma for clinicians facing a patient who has time-critical needs (such as unmanaged airway compromise) and can be further exacerbated by the presence of emotional or aggressive relatives or bystanders.

Some strategies to mitigate this include:

• Having pre-prepared size-appropriate PPE in an easily accessible pouch to save time
• Donning PPE prior to arrival on scene if time-critical AGPs are likely to be required or high expressed emotion may be anticipated from relatives or onlookers on scene
• Senior clinicians arriving on scene can provide advice regarding patient management to those in PPE (at a safe distance), prior to donning Level 3 themselves
• As with any pre-hospital scene, clinicians should make a dynamic risk assessment based on the specific circumstances encountered

Pre-hospital PPE bag & example contents

Practical Considerations on Scene

When & Where to Don PPE

In cases where AGPs are anticipated but not immediately required, clinicians must consider when in the job cycle to don Level 3 PPE. As already discussed, delaying initial assessment can be difficult, however moving away from the patient, to don PPE once contact has been made, risks loss of situational awareness or control of the scene and impaired communication between teams.

On the other hand, by performing an initial scene assessment and primary survey, senior clinicians are better placed to guide clinical management and can chose the most efficient time to don Level 3 PPE.

Another key decision is where to don PPE. This ideally needs to be performed at an appropriate distance from the patient and in a clean area, but must be balanced against loss of visual or verbal contact with the patient and scene. Environmental factors can make this challenging, for example trying to don suits or tie aprons in very wet or windy environments. Consideration must also be given to donning Level 3 PPE before entering any closed environment where AGPs have already been conducted, such as inside an ambulance or confined space on scene.

Location and Setup of the RSI Kit Dump

In addition to the usual environmental considerations for locating an RSI Kit Dump, additional pandemic considerations include wind direction, which should be away from the intubation team, and allowing additional space to place kit bags two meters away. Within the kit dump only essential equipment should be set up next to the patient to minimise contamination of pouches and bags. Any required “on the person” medical equipment (such a thoracostomy kit) should be removed from pockets prior to any AGP. Personal radios must also be accessible outside of PPE and decontaminated at the end of the job cycle. Only clinicians in Level 3 PPE should enter the kit dump area and, resource permitting, a clinician should be allocated as a “clean runner” – who can obtain additional equipment in an emergency.

Example schematic of COVID 19 modifications to the RSI kit dump Credit: KSS Standard Operating Procedures

Modifications to the Conduct of RSI

Many of the strategies utilised for COVID-19 intubations in hospital have been well established in pre-hospital practice – such as use of checklists, dedicated equipment packs, simulation training and role allocation.

However, a number of changes to the pre-hospital RSI process have been adopted to minimise aerosol and droplet contamination; these include first line use of video laryngoscopy, use of closed circuit suction catheters and avoidance of manual ventilation during the apnoeic phase. The bougie should be handled with extreme care after use and the use of a stethoscope to confirm tube placement should be avoided. HME filters should be attached close to the ETT, ventilator circuits should be checked to ensure tight fitting connections and the ETT should be clamped if a circuit disconnection is required. Use of PEEP should be considered during pre-oxygenation and post-intubation to reduce desaturation events.

Conduct of pre-hospital intubation by team in Level 3 PPE

The use of Level 3 PPE (particularly masks, googles/visor and hoods) has come with challenges – on an individual level and for team crew resource management (CRM). This has increased reliance on well-drilled procedures and the importance of appropriate team training for pre-hospital COVID-19 intubation cannot be overstated.

Individual and team CRM challenges of Level 3 PPE during intubation

Transport Dynamics

Ambulance Considerations:

When transporting patients with suspected or confirmed COVID-19 by road it is important to close all cupboard doors, store clean equipment and seal the window to the cab. Clinicians should remain in Level 3 PPE throughout transfer and if appropriate the roof window should opened for ventilation.

Aviation Considerations:

Patients may be transported by air if the aircraft has been prepared with an airtight seal between the cockpit and cabin. Depending on helicopter type and ventilation system, patients may need to be loaded onto aircraft with the auxiliary power unit (APU) running. Noise from the APU mandates the use of helmets and connecting to the aircraft intercom system; in addition the pilots cannot directly assist with loading the patient. Performance of AGPs inside the aircraft should be avoided wherever possible.

APU Load

Conclusions

The COVID-19 pandemic has presented huge burden for ambulance services and pre-hospital clinicians. Airway management in these conditions raises technical, non-technical, moral and psychological challenges. Prior consideration, planning and training for these challenges is essential at an organisational and individual level. Importantly, the lessons learned during the COVID-19 pandemic are relevant for other droplet/aerosol spread viruses.