Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
Office for Infection Control, Asan Medical Center, Seoul, South Korea.
Infect Control Hosp Epidemiol. 2021 Nov;42(11):1313-1317. doi: 10.1017/ice.2021.5. Epub 2021 Jan 25.
We quantitatively assessed the fit failure rate of N95 respirators according to the number of donning/doffing and hours worn.
Experimental study.
A tertiary-care referral center in South Korea.
In total, 10 infection control practitioners participated in the fit test.
The first experiment comprised 4 consecutive 1-hour donnings and fit tests between each donning. The second experiment comprised 2 consecutive 3-hour donnings and fit tests between each donning. The final experiment comprised fit tests after an 1-hour donning or a 2-hour donning.
For 1-hour donnings, 60%, 70%, and 90% of the participants had fit failures after 2, 3, and 4 consecutive donnings, respectively. For 3-hour donnings, 50% had fit failure after the first donning and 70% had failures after 2 consecutive donnings. All participants passed the fit test after refitting whenever fit failure occurred. The final experiment showed that 50% had fit failure after a single use of 1 hour, and 30% had fit failure after a single use of 2 hours.
High fit-failure rates were recorded after repeated donning and extended use of N95 respirators. Caution is needed for reuse (≥1 time) and extended use (≥1 hour) of N95 respirators in high-risk settings such as those involving aerosol-generating procedures. Although adequate refitting may recover the fit factor, the use of clean gloves and strict hand hygiene afterward should be ensured when touching the outer surfaces of N95 respirators for refitting.
根据佩戴/脱下次数和佩戴时间，定量评估 N95 呼吸器的贴合失败率。
实验研究。
韩国一家三级保健转诊中心。
共有 10 名感染控制从业者参加了适配测试。
第一项实验包括连续 4 次 1 小时佩戴和每次佩戴之间的适配测试。第二项实验包括连续 2 次 3 小时佩戴和每次佩戴之间的适配测试。最后一项实验包括 1 小时佩戴或 2 小时佩戴后的适配测试。
对于 1 小时的佩戴，分别有 60%、70%和 90%的参与者在连续 2、3 和 4 次佩戴后出现贴合失败。对于 3 小时的佩戴，50%的参与者在第一次佩戴后出现贴合失败，70%的参与者在连续两次佩戴后出现失败。每次贴合失败时，所有参与者都通过重新适配通过了测试。最后一项实验表明，50%的参与者在单次使用 1 小时后出现贴合失败，30%的参与者在单次使用 2 小时后出现贴合失败。
重复佩戴和延长使用 N95 呼吸器后，记录到高贴合失败率。在涉及气溶胶生成程序等高风险环境中，对于 N95 呼吸器的重复使用（≥1 次）和延长使用（≥1 小时）需要谨慎。虽然充分的重新适配可以恢复贴合因素，但在接触 N95 呼吸器的外表面进行重新适配时，应确保使用干净的手套并严格进行手部卫生。
