Reade Samuel J, Bassam Ahmad, Al-Bassam Wisam, Kadam Umesh
Monash Health - Intensive Care Services, Clayton, VIC, Australia.
Monash Health - Intensive Care Services, Clayton, VIC, Australia.
Aust Crit Care. 2025 Jan;38(1):101099. doi: 10.1016/j.aucc.2024.07.080. Epub 2024 Aug 23.
AIM/OBJECTIVES: Fit testing of N95/FFP2 respirators is universally recommended before exposure to airborne infectious diseases such as COVID-19. Respirator supply shortage in the COVID-19 pandemic encouraged extended-use for up to 4 h, despite uncertainty about seal integrity over time. The aim of our study was to assess N95 seal integrity after at least 2 h of continuous clinical use in the intensive care unit (ICU). We hypothesised that seal integrity would deteriorate over time, with variability between respirator shapes.
A prospective cohort study of healthcare workers in a metropolitan ICU setting in Australia between April 2021 and August 2022. Following consent and screening, participants underwent qualitative fit testing in the ICU, and fit tests were repeated following a continuous period of at least 2-h usage. The primary outcome was N95 fit-test failure rate measured by qualitative fit testing of >2 h compared to baseline. Secondary outcomes evaluated effects of respirator shape, demographic characteristics, and duration of respirator use on respirator fit after 2 h use.
Fifty-one participants were recruited and consented. Six participants were excluded; four failed baseline fit test, one could not taste saccharin, and one did not complete 2 h of usage. Fourteen of 45 participants (∼31%) failed the extended-use fit test (median duration: 2 h 10 min [interquartile range: 2:07-2:20]). Fit-test rates differed between respirator shapes; three-piece flat-fold respirators had lower failure rates (6/32; 19%) than duckbill-shaped respirators (6/11; 55%) p = 0.046. No other demographic characteristic or respirator shape was significantly associated with increased failure rate.
Following 2 h of use, approximately 30% of participants failed repeat fit testing, suggesting incomplete respiratory protection. Three-piece flat-fold respirators outperformed duckbill respirators. Extended use of respirators, even without respirator reuse, may put healthcare workers at risk of inadequate respiratory protection, in particular when using duckbill-shaped respirators.
在接触如新冠病毒病等空气传播传染病之前，普遍建议对N95/FFP2呼吸器进行适合性测试。新冠疫情期间呼吸器供应短缺，促使人们将其延长使用长达4小时，尽管随着时间推移密封完整性存在不确定性。我们研究的目的是评估在重症监护病房（ICU）连续临床使用至少2小时后N95呼吸器的密封完整性。我们假设密封完整性会随着时间推移而恶化，且不同形状的呼吸器之间存在差异。
对2021年4月至2022年8月期间澳大利亚一家大都市ICU环境中的医护人员进行一项前瞻性队列研究。在获得同意并经过筛选后，参与者在ICU进行定性适合性测试，并在连续使用至少2小时后重复进行适合性测试。主要结局是通过与基线相比>2小时的定性适合性测试测量的N95适合性测试失败率。次要结局评估呼吸器形状、人口统计学特征和呼吸器使用时长对使用2小时后呼吸器适合性的影响。
招募并获得51名参与者同意。6名参与者被排除；4名基线适合性测试未通过，1名尝不出糖精味，1名未完成2小时的使用。45名参与者中有14名（约31%）延长使用适合性测试未通过（中位时长：2小时10分钟[四分位间距：2:07 - 2:20]）。不同形状呼吸器的适合性测试通过率不同；三件式平面折叠呼吸器的失败率（6/32；19%）低于鸭嘴形呼吸器（6/11；55%），p = 0.046。没有其他人口统计学特征或呼吸器形状与失败率增加显著相关。
使用2小时后，约30%的参与者重复适合性测试未通过，提示呼吸防护不完全。三件式平面折叠呼吸器表现优于鸭嘴形呼吸器。呼吸器的延长使用，即使不重复使用呼吸器，也可能使医护人员面临呼吸防护不足的风险，尤其是在使用鸭嘴形呼吸器时。
