key: cord-0824350-b8gtwdxc
authors: Goldhaber-Fiebert, Sara N.; Greene, Jeremy A.; Garibaldi, Brian T.
title: Low-flow Nasal Cannula and Potential Nosocomial Spread of COVID-19
date: 2020-05-18
journal: Br J Anaesth
DOI: 10.1016/j.bja.2020.05.011
sha: 5d83603e52f8c9abc286a3bba29b050e19697e0c
doc_id: 824350
cord_uid: b8gtwdxc

nan

contamination risks remain. During the first SARS epidemic, supplemental oxygen therapy emerged as a risk factor for nosocomial transmission on open wards, equivalent to patient bed crowding and failure to provide washing stations for providers. 8 Even with single-occupancy rooms, healthcare providers could be exposed to or spread SARS-CoV-2 after touching contaminated surfaces surrounding unsuspected COVID-19 patients presenting for other reasons. In a recent study, researchers sampling air inside COVID-19 negative-pressure patient rooms found the highest concentration of viral RNA in the room of a patient who was on oxygen 1 L min -1 by nasal cannula, with no documented cough, 9 though in this context clinicians were wearing full protective equipment.

Some institutions have begun covering low-flow nasal cannula, at least in certain contexts, 10 11 though discussions with peers across specialities and institutions suggest that practice is far from uniform and is often limited to known COVID-19 patients. Existing data should give institutions pause to consider the infection risks of oxygen delivery, especially in cases where oxygen use is informed by habit, rather than evidence of clinical benefit. When low-flow oxygen via nasal cannula is clearly indicated, simple strategies can be employed to mitigate the risk of spread. For example, prior to extubation, nasal cannula can be placed and covered with a surgical mask to limit the potential for environmental contamination. 11 By a conservative estimate, if 10% of the occupants of the roughly one-million hospital beds in the US are on low-flow nasal cannula oxygen on any given day, that translates into 100,000 patients in US hospitals whose treatment may also be adding to nosocomial spread of SARS-CoV-2. Local conditions and supplies should guide considerations of using surgical masks to cover all low-flow nasal cannulae. If surgical masks are in short supply, other coverings, including cloth masks, might be of use. Where universal patient testing becomes feasible, or there are sufficient masks for all hospitalized patients, specifically covering nasal cannula becomes less important. More work is needed to determine the clinical effectiveness of covering nasal cannulae with masks, and which coverings work best.

With many governments currently encouraging everyone to wear cloth masks in public to decrease spread, our healthcare systems should likewise consider the potential risks from the constant blowing of uncovered, loose-fitting, low-flow nasal cannula oxygen.

The authors declare no conflicts of interest

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