Department of Surgery, UCLA David Geffen School of Medicine, Los Angeles, California.
Louise M. Darling Biomedical Library, UCLA Library, University of California, Los Angeles.
JAMA. 2021 Apr 6;325(13):1296-1317. doi: 10.1001/jama.2021.2531.
The COVID-19 pandemic has resulted in a persistent shortage of personal protective equipment; therefore, a need exists for hospitals to reprocess filtering facepiece respirators (FFRs), such as N95 respirators.
To perform a systematic review to evaluate the evidence on effectiveness and feasibility of different processes used for decontaminating N95 respirators.
A search of PubMed and EMBASE (through January 31, 2021) was completed for 5 types of respirator-decontaminating processes including UV irradiation, vaporized hydrogen peroxide, moist-heat incubation, microwave-generated steam, and ethylene oxide. Data were abstracted on process method, pathogen removal, mask filtration efficiency, facial fit, user safety, and processing capability.
Forty-two studies were included that examined 65 total types of masks. All were laboratory studies (no clinical trials), and 2 evaluated respirator performance and fit with actual clinical use of N95 respirators. Twenty-seven evaluated UV germicidal irradiation, 19 vaporized hydrogen peroxide, 9 moist-heat incubation, 10 microwave-generated steam, and 7 ethylene oxide. Forty-three types of N95 respirators were treated with UV irradiation. Doses of 1 to 2 J/cm2 effectively sterilized most pathogens on N95 respirators (>103 reduction in influenza virus [4 studies], MS2 bacteriophage [3 studies], Bacillus spores [2 studies], Escherichia virus MS2 [1 study], vesicular stomatitis virus [1 study], and Middle East respiratory syndrome virus/SARS-CoV-1 [1 study]) without degrading respirator components. Doses higher than 1.5 to 2 J/cm2 may be needed based on 2 studies demonstrating greater than 103 reduction in SARS-CoV-2. Vaporized hydrogen peroxide eradicated the pathogen in all 7 efficacy studies (>104 reduction in SARS-CoV-2 [3 studies] and >106 reduction of Bacillus and Geobacillus stearothermophilus spores [4 studies]). Pressurized chamber systems with higher concentrations of hydrogen peroxide caused FFR damage (6 studies), while open-room systems did not degrade respirator components. Moist heat effectively reduced SARS-CoV-2 (2 studies), influenza virus by greater than 104 (2 studies), vesicular stomatitis virus (1 study), and Escherichia coli (1 study) and preserved filtration efficiency and facial fit for 11 N95 respirators using preheated containers/chambers at 60 °C to 85 °C (5 studies); however, diminished filtration performance was seen for the Caron incubator. Microwave-generated steam (1100-W to 1800-W devices; 40 seconds to 3 minutes) effectively reduced pathogens by greater than 103 (influenza virus [2 studies], MS2 bacteriophage [3 studies], and Staphylococcus aureus [1 study]) and maintained filtration performance in 10 N95 respirators; however, damage was noted in least 1 respirator type in 4 studies. In 6 studies, ethylene oxide preserved respirator components in 16 N95 respirator types but left residual carcinogenic by-product (1 study).
Ultraviolet germicidal irradiation, vaporized hydrogen peroxide, moist heat, and microwave-generated steam processing effectively sterilized N95 respirators and retained filtration performance. Ultraviolet irradiation and vaporized hydrogen peroxide damaged respirators the least. More research is needed on decontamination effectiveness for SARS-CoV-2 because few studies specifically examined this pathogen.
COVID-19 大流行导致个人防护设备持续短缺；因此，医院需要重新处理过滤式面罩呼吸器（例如 N95 呼吸器）。
进行系统评价，评估用于消毒 N95 呼吸器的不同过程的有效性和可行性的证据。
通过对 PubMed 和 EMBASE（截至 2021 年 1 月 31 日）的搜索，完成了 5 种呼吸器消毒过程的研究，包括紫外线照射、汽化过氧化氢、湿热孵育、微波产生的蒸汽和环氧乙烷。数据摘要了过程方法、病原体去除、口罩过滤效率、面部贴合、用户安全和处理能力。
共纳入 42 项研究，共检查了 65 种口罩。所有都是实验室研究（无临床试验），其中 2 项评估了 N95 呼吸器的实际临床使用情况和呼吸器性能和贴合度。27 项评估了紫外线杀菌照射，19 项评估了汽化过氧化氢，9 项评估了湿热孵育，10 项评估了微波产生的蒸汽，7 项评估了环氧乙烷。用紫外线照射处理了 43 种 N95 呼吸器。1 至 2 J/cm2 的剂量可有效消毒 N95 呼吸器上的大多数病原体（4 项研究中流感病毒减少>103，3 项研究中 MS2 噬菌体减少>103，2 项研究中芽孢杆菌减少>103，1 项研究中大肠杆菌噬菌体减少>103，1 项研究中水疱性口炎病毒减少>103，1 项研究中中东呼吸综合征病毒/SARS-CoV-1 减少>103），而不会降解呼吸器组件。根据 2 项研究表明 SARS-CoV-2 减少大于 103，可能需要更高于 1.5 至 2 J/cm2 的剂量。汽化过氧化氢在所有 7 项功效研究中都消灭了病原体（3 项研究中 SARS-CoV-2 减少>104，4 项研究中芽孢杆菌和嗜热脂肪芽孢杆菌孢子减少>106）。使用更高浓度过氧化氢的加压室系统导致 FFR 损坏（6 项研究），而开放式系统不会降解呼吸器组件。湿热有效地减少了 SARS-CoV-2（2 项研究）、流感病毒（2 项研究）、水疱性口炎病毒（1 项研究）和大肠杆菌（1 项研究），并保持了 11 种 N95 呼吸器的过滤效率和面部贴合性，使用预加热的容器/室在 60°C 至 85°C（5 项研究）；然而，Caron 孵化箱的过滤性能下降。微波产生的蒸汽（1100-W 至 1800-W 设备；40 秒至 3 分钟）可有效减少大于 103 的病原体（流感病毒[2 项研究]、MS2 噬菌体[3 项研究]和金黄色葡萄球菌[1 项研究]），并保持 10 种 N95 呼吸器的过滤性能；然而，在 4 项研究中，至少有 1 种呼吸器类型受损。在 6 项研究中，环氧乙烷保留了 16 种 N95 呼吸器类型的呼吸器组件，但留下了残留的致癌副产物（1 项研究）。
紫外线杀菌照射、汽化过氧化氢、湿热和微波产生的蒸汽处理可有效消毒 N95 呼吸器并保持过滤性能。紫外线照射和汽化过氧化氢对呼吸器的损坏最小。需要对 SARS-CoV-2 的消毒效果进行更多研究，因为很少有研究专门研究这种病原体。
