N95 Reuse During COVID-19

Frontline healthcare workers are at high risk of SARS (severe acute respiratory syndrome) CoV-2 (COVID-19) infection. Personal protective equipment (PPE), such as an N95 respirator (N95), is essential for prevention of COVID-19 among HCWs. N95s can prevent aerosolized transmission of viral particles and reduce COVID-19 among HCWs, helping to reduce infection rates and preserve the workforce. Under normal circumstances, the CDC recommends that HCWs dispose of N95s after a single patient encounter. However, during critical PPE shortages such as those during the current COVID-19 pandemic, the CDC recommends N95 extended use (wearing the same N95 for multiple patient encounters) and re-use (storing an N95 between shifts for use over multiple shifts). N95 shortages have been widely reported during the COVID-19 pandemic and have forced HCWs to practice extended use and reuse of N95s. Despite the CDC's guidelines, there are limited data regarding the efficacy of N95s under conditions of extended use and reuse and existing studies have been conducted in laboratory settings rather than in the actual health care environment. (Bergman 2012; Vuma et al 2019). This has left health care workers, including emergency department (ED) providers on the front lines of the COVID-19 pandemic, without clear guidance regarding N95 conservation. Many have implemented various reuse and extended use policies out of necessity but with no empirical evidence of their safety and effectiveness. The study team conducted a pilot cross-sectional study of 68 ED providers who wore either a 3M 1860 dome style N95 or a duckbill N951. 70.6% of duckbill N95 failed a standardized fit test with 3M bitter solution and a hood. Of the dome style , 27.5% failed a fit test. N95 failure was associated with increasing numbers of shifts used: There were 0/11 failures after 1 shift, 1/12 failures after 2 shifts, 3/13 failures after 3 shifts, and 10/15 failures after 4 or more shifts. Also, more donnings and doffings were associated with fit failure, with a median of 8 donning and doffings in the fit pass group and 15 donning and doffings in the fit failure group. This preliminary study had a number of limitations, including a small sample size, convenience sampling, and cross-sectional design, and so was unable to definitively identify the number of shifts or donnings/doffings for which N95s can be safely reused. The investigators propose to conduct a prospective cohort study of 396 participants across 6 ED sites to estimate the cumulative incidence of N95s when subjected to extended use and reuse in a clinical (emergency department) setting with fit test failure and contamination as the main endpoints. The investigators also seek to compare the fit test failure between varying types of HCWs wearing a number of N95 types. Additionally, the investigators will collect the N95s used in this study for additional analyses of at an outside laboratory measuring COVID-19 contamination levels and filtration efficiency.