Lockhart et al. provide a considered exploration of COVID-19 infection-control issues specific to anaesthesiologists, proposing an additional third category of personal protective equipment (PPE).

Give it to me in point form!

They propose three PPE types:

1. Droplet & contact precaution PPE: surgical mask, gown, gloves.
2. General airborne, droplet & contact PPE: addition of N95 respirator mask and eye protection.
3. PPE for high-risk aerosol-generating medical procedures: addition of gown neck protection and double gloves.

Why should I take notice?

The Canadian view on PPE is tempered by both their current significant COVID burden, and their experience of the 2003 SARS pandemic which infected 257 Canadians, 20% of whom were healthcare workers. Much of our PPE evidence is based upon SARS. This article emphasises the importance of PPE for anaesthesiologists and their airway assistants.

On airborne spread?

Unfortunately much of what we did not know about respiratory spread and SARS in 2005 persists today:

Although this observation [about lack of knowledge of SARS infectious droplets] was made 15 years ago, basic questions regarding nosocomial spread during the SARS epidemic, and now the COVID-19 pandemic, have yet to be answered.

Absence of evidence however, should not imply evidence of absent airborne spread.

The role of airborne particles in the spread of COVID-19 remains unclear, although Lockhart notes the infamous case of Hong Kong's Amoy Gardens housing complex in the 2003 SARS outbreak, resulting in 187 cases – likely via airborne spread.

Endotrachial intubation has been shown in several studies to be a high-risk procedure for healthcare worker infection. Considering this the authors reccomend a third level of PPE, adding:

1. AAMI level-2 gown, incluidng neck protection, noting that the neck is a high-risk area for contamination in simulation studies.
2. Double gloves that overlap the sleeve, noting that the gown-glove interface is a common PPE failure site, and that Verbeek's 2020 Cochrane review concluded that there was less contamination vs single gloving (RR 0.36).

Additionally:

• Only allow presence of essential staff in room during AGP.
• Provide access to shower resources for staff after high-risk AGP.
• Do not ‘‘MacGyver’’ homemade combinations of PPE.
• Doffing is a high-risk critical moment, that should not be rushed, distractions should be minimised, and use a doffing supervisor. Pay attention when donning to ease later doffing.
• Masks should be the last item removed.

Final word

Lockhart emphasises that there is no ideal PPE, but by focusing on consistent protection at known high-risk interactions (ie. intubation) safety improvements can be made.

summary

• Shannon L Lockhart, Laura V Duggan, Randy S Wax, Stephan Saad, and Hilary P Grocott.
• Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC, Canada.
• Can J Anaesth. 2020 Aug 1; 67 (8): 1005-1015.

AbstractHealthcare providers are facing a coronavirus disease pandemic. This pandemic may last for many months, stressing the Canadian healthcare system in a way that has not previously been seen. Keeping healthcare providers safe, healthy, and available to work throughout this pandemic is critical. The consistent use of appropriate personal protective equipment (PPE) will help assure its availability and healthcare provider safety. The purpose of this communique is to give both anesthesiologists and other front-line healthcare providers a framework from which to understand the principles and practices surrounding PPE decision-making. We propose three types of PPE including: 1) PPE for droplet and contact precautions, 2) PPE for general airborne, droplet, and contact precautions, and 3) PPE for those performing or assisting with high-risk aerosol-generating medical procedures.

This article appears in the collection: Anaesthesiology, Personal Protective Equipment (PPE) and COVID.

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