Respirators and complications of airway management

We read with interest the article by Potter et al. [1]. The authors concluded that the use of respirators by anaesthetists was associated with increased risk of complications of airway management, specifically desaturation and difficult facemask ventilation. We have been continuously wearing N95 filtering facepiece (FFP) or elastomeric respirators while providing patient care since the early phases of the COVID‐19 pandemic in April 2020. We have also advocated for anaesthetists to wear respirators while providing patient care on a universal basis, whether or not patients are known or suspected of being infected with SARS‐CoV‐2 [2, 3]. Based on our personal experience and the literature describing the use of respirators in healthcare, we are sceptical of the results of the study by Potter et al., and we are unaware of any plausible explanation for an increase in complications of airway management depending on whether anaesthetists are wearing respirators or fluid‐resistant surgical masks. The authors suggest that discomfort caused by wearing a respirator or difficulty in communication might be the explanation; in our personal experience, this seems very unlikely. Interestingly, a simulation study of the Australian Defence Force chemical, biological, radiological and nuclear air‐purifying mask, which is a full‐face elastomeric respirator, sometimes referred to colloquially as a ‘gas mask’, was judged to be preferable to N95 respirators by ICU nursing, medical and allied health staff; the simulation included tracheal intubation of a manikin [4]. This counterintuitive preference for a full‐face respirator demonstrates the potential complexity of assessing the effect of respirators on provider acceptance and performance.

More likely than not, the association between respirator use and airway management complications resulted from unrecognised confounders. As the authors have stated in their discussion, “There was also a lack of adherence to the guidelines at the time of the data collection for the study: respiratory protection was only used in 44.2% of patients who were SARS‐CoV‐2 positive/unclear, and was used in 13.0% of patients who were SARS‐CoV‐2 negative. These findings raise the possibility of PPE use being focused on certain procedures or patients judged by the anaesthetist as being of high risk which might lead to confounding and influence the reliability of results.” We agree with this assessment. In addition, there was a greater increase in the odds of airway complications associated with pre‐oxygenation than with respirator use (74% vs. 38%, respectively). To the best of our knowledge, pre‐oxygenation is expected to reduce the risk of complications of airway management, and as the authors point out, an association between pre‐oxygenation and complications of airway management does not imply a causal relationship.

Ironically, readers of the article may use the putative connection between respirators and complications of airway management as an argument not to wear respirators during patient care, which in our opinion, puts patients and clinicians at greater risk of infection with dangerous pandemic respiratory pathogens. Notably, a recently published study has provided evidence that respirators protect healthcare workers from infection [5].