Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital, Boston, MA, USA.
Department of Anaesthesia, Harvard Medical School, Boston, MA, USA.
Paediatr Anaesth. 2020 Nov;30(11):1269-1274. doi: 10.1111/pan.13990. Epub 2020 Dec 2.
During the coronavirus pandemic, preventing contamination of the anesthesia machine, critical to avoid cross-contamination between patients, has proven challenging when treating premature infants and neonates. While attaching a HEPA filter to the endotracheal tube will protect the anesthesia machine and the gas sampling line from contamination, this contribution to the dead space makes ventilation of these small patients challenging. Direct filtration of the gas sampling line eliminates this problem; however, appropriate filters are not readily available.
Identify a small filter capable of filtering out particles of a size similar to the SARS-CoV-2 virus for the gas sampling line.
We used fluorescence microspheres suspended in a solution for a challenge test to determine the filtration efficiency of various filters. The microspheres varied in diameter (0.02 µm, 0.042 µm, 0.109 µm, and 0.989 µm). A fluorescence plate reader was used to evaluate the degree of fluorescence intensity in the flow-through from various filters and referenced to the fluorescence intensity of the input.
AHEPA filter, as recommended as an anti-viral filter, effectively filtered all the particles tested. The B. Braun PERIFIX Flat Epidural Filter was the second most effective filter, filtering particles larger than 0.042 µm. Other filters tested did not filter fluorescence microspheres equivalent in size to a single coronavirus particle (0.07 µm).
Although the Food and Drug Administration (FDA) has not approved the Flat Epidural Filter for use as an anesthesia machine gas filter, our simple challenge test suggests that it could be used to effectively filter the anesthesia gas sampling line.
在冠状病毒大流行期间，防止麻醉机污染对于避免患者之间的交叉污染至关重要，而在治疗早产儿和新生儿时，这一点证明具有挑战性。虽然将高效空气颗粒过滤器（HEPA）过滤器连接到气管内导管上可以保护麻醉机和气体采样线免受污染，但这会增加死腔，使这些小患者的通气变得困难。直接对气体采样线进行过滤可以解决此问题；但是，合适的过滤器并不容易获得。
为气体采样线找到一种能够过滤出类似于 SARS-CoV-2 病毒大小的颗粒的小型过滤器。
我们使用悬浮在溶液中的荧光微球进行了一项挑战测试，以确定各种过滤器的过滤效率。微球的直径不同（0.02 µm、0.042 µm、0.109 µm 和 0.989 µm）。荧光板读数器用于评估各种过滤器的透过液中的荧光强度，并与输入的荧光强度进行参考。
AHEPA 过滤器（推荐用于抗病毒过滤器）可有效过滤所有测试的颗粒。B. Braun PERIFIX 平型硬膜外过滤器是第二有效的过滤器，可过滤大于 0.042 µm 的颗粒。其他测试的过滤器无法过滤与单个冠状病毒颗粒（0.07 µm）等效的荧光微球。
尽管美国食品和药物管理局（FDA）尚未批准平型硬膜外过滤器用于麻醉机气体过滤器，但我们的简单挑战测试表明，它可以有效地过滤麻醉气体采样线。
