key: cord-0760078-wmse3hgu
authors: Gupta, Anju; Aravindan, Ajisha; Soni, Kapil Dev
title: Donning N95 respirator masks during COVID-19 pandemic: look before you leap!
date: 2021-03-21
journal: Braz J Anesthesiol
DOI: 10.1016/j.bjane.2021.02.034
sha: ba6148b78821c72611440360a1339e1fa3db2ae9
doc_id: 760078
cord_uid: wmse3hgu

nan

adequate seal. However, a regular Fit Test is time-consuming, and all sizes may not be available. So, the test may not be practical for every HCWs in a pandemic situation. Also, during such outbreaks, PPE are searched from multiple sources on urgent basis. Hence, end users may not get time to be familiarized with these, and chances of improper usage increase.

User Seal check (either positive pressure or negative pressure) is an easily performed measure which should be a mandatory step for N95 respirator donning process prior to entering the patient care area. [4] During a positive pressure seal check (useful for non-valved masks and not applicable for valved masks), the person exhales gently while obstructing the paths for air to exit the mask. A successful check is when the facemask is slightly pressurized before the increased pressure causes outward leakage. During a negative pressure user seal test (useful for both valved and non-valved masks), the N95 user inhales briskly while hindering the paths for air to enter the facemask. A successful check is when the mask collapses slightly under the negative pressure thus created. National Institute of Occupational Safety and Health (NIOSH) data indicates that performing a user seal check leads to higher quality donning. [5] Nonetheless, the OSHA warns that seal checks does not have the sensitivity and specificity to replace fit tests.

We started doing negative pressure seal test (for valved masks) and both positive and negative pressure seal tests for non-valved masks. Unsurprisingly, most of valved masks failed the test for thin built HCWs. Duckbilled non-valved masks fared best in terms of seal for majority. To curtail the wastage, we folded the margin of the mask fitting the chin on itself in the middle and stapled (with the staple pin bending towards outside to avoid hurting the person) ( Fig. 1B) . A negative pressure seal test performed subsequently confirmed a good seal (Fig. 1C) . For minor irregularities in fitment, applying adhesive tapes all around or wearing the lower tie band more cephalad could rectify the ill fit. Many N95 masks have adjustable tieband sizes and need to be tightened as per patient's fitment requirement. While applying any such tapes to the mask, care should be taken to fold one edge of the tape so that it can be easily removed during doffing without creating additional risk to the HCWs.

No previous study has identified the impact of ill-fitted N95 respirators on the transmission of COVID-19. Awareness of the importance of maintaining an adequate mask seal is of pivotal importance to prevent transmission of infection to the HCWs during the present COVID-19 outbreak.

We, therefore, would advise caution in the use of these respirators by ensuring proper seal before entering patient care areas. The use of positive and/or negative pressure seal check should be universally adopted by all wearing these respirators. We also would like to urge the J o u r n a l P r e -p r o o f manufacturers to deliberate into mask designs universally acceptable to all healthcare workers irrespective of the race, facial configuration, and gender.

The authors declare no conflicts of interest.

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