Department of Plastic Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA.
US Army Research Laboratory, Adelphi, MD.
Ann Emerg Med. 2021 Jan;77(1):1-10. doi: 10.1016/j.annemergmed.2020.08.033. Epub 2020 Sep 3.
Throughout the coronavirus disease 2019 pandemic, many emergency departments have been using passive protective enclosures ("intubation boxes") during intubation. The effectiveness of these enclosures remains uncertain. We sought to quantify their ability to contain aerosols using industry standard test protocols.
We tested a commercially available passive protective enclosure representing the most common design and compared this with a modified enclosure that incorporated a vacuum system for active air filtration during simulated intubations and negative-pressure isolation. We evaluated the enclosures by using the same 3 tests air filtration experts use to certify class I biosafety cabinets: visual smoke pattern analysis using neutrally buoyant smoke, aerosol leak testing using a test aerosol that mimics the size of virus-containing particulates, and air velocity measurements.
Qualitative evaluation revealed smoke escaping from all passive enclosure openings. Aerosol leak testing demonstrated elevated particle concentrations outside the enclosure during simulated intubations. In contrast, vacuum-filter-equipped enclosures fully contained the visible smoke and test aerosol to standards consistent with class I biosafety cabinet certification.
Passive enclosures for intubation failed to contain aerosols, but the addition of a vacuum and active air filtration reduced aerosol spread during simulated intubation and patient isolation.
在 2019 年冠状病毒病大流行期间，许多急诊科在进行插管时使用被动保护罩（“插管盒”）。这些外壳的有效性仍不确定。我们试图使用行业标准测试协议来量化它们包含气溶胶的能力。
我们测试了一种代表最常见设计的商业上可用的被动保护罩，并将其与改良的保护罩进行了比较，该改良的保护罩在模拟插管和负压隔离期间采用了主动空气过滤的真空系统。我们使用空气过滤专家用来认证 I 级生物安全柜的 3 项相同测试来评估外壳：使用中性浮力烟雾进行视觉烟雾模式分析，使用模拟含有病毒颗粒的大小的测试气溶胶进行气溶胶泄漏测试，以及空气速度测量。
定性评估显示烟雾从所有被动外壳开口逸出。气溶胶泄漏测试表明，在模拟插管期间，外壳外的颗粒浓度升高。相比之下，配备真空过滤的外壳完全包含可见烟雾和测试气溶胶，符合 I 级生物安全柜认证标准。
用于插管的被动外壳未能包含气溶胶，但增加了真空和主动空气过滤，减少了模拟插管和患者隔离期间气溶胶的传播。
