The surgical mask in the 21st century

Excessive use of both disposable surgical masks and P2/N95 surgical respirators has led to dramatic shortages of these items. This has led to a whole range of problems including poorly informed attempts at mask reuse or improvisation.

This study provides a review of medical grade facial protection (surgical masks, N95 respirators and face shields), the safety and efficacy of decontamination methods and the utility of alternative strategies in emergency shortages or resource-scarce settings. The authors conducted a scoping review of PubMed and grey literature related to facial protection and potential adaptation strategies in the setting of PPE shortages (January 2000 to March 2020). Not surprisingly, there was little published evidence around COVID-19 specifically, however there is an extensive literature around the performance of various types of facial protection devices, particular with regard to influenza and other respiratory viruses. A total of 5,462 peer-reviewed articles and 41 grey literature records were retrieved. From these, 67 met inclusion criteria for the precise topic of the review. The major conclusions that were reached were as follows: Compared with surgical masks, P2/N95 respirators perform better in laboratory testing of particle filtration efficiency. When worn properly, with fit testing and fit checking, they may provide superior protection in inpatient settings (such as hospitals and healthcare facilities), but they only perform at a similar level to traditional disposable surgical masks in outpatient settings. This is because of poor adaptation and poor mask fitting and mask wearing habits, by both healthcare workers and by patients. While there have been attempts at strategies to conserve surgical masks and N95 respirators, these all suffer from problems, including dramatically reduced performance with extended use and there are known problems with attempts at reuse or decontamination, which impair the performance of the mask or respirator, resulting in inferior protection. When there have been critical shortages of medical-grade PPE, alternative forms of facial protection (e.g. industrial N95 masks designed for dust protection) offer inferior protection.

Garcia Godoy LT, et al. Facial protection for healthcare workers during pandemics: a scoping review. BMJ Global Health 2020 May;5(5):e002553.