Efficacy of face shields against cough aerosol droplets from a cough simulator.
Efficacy of face shields against cough aerosol droplets from a cough simulator.
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DOI：
10.1080/15459624.2013.877591
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发表时间：
2014
影响因子：
2
通讯作者：
Beezhold DH
中科院分区：
文献类型：
--
作者：
Lindsley WG;Noti JD;Blachere FM;Szalajda JV;Beezhold DH
医护人员在为咳嗽患者提供常规护理时会接触到可能具有传染性的空气颗粒物。然而，人们对这些气溶胶的行为及其构成的风险还不太了解。我们使用了一个咳嗽病人模拟器和一个呼吸工作者模拟器来调查医护人员对咳嗽气溶胶飞沫的暴露，并检查面罩在减少这种暴露方面的功效。我们的研究结果表明，0.9%的咳嗽气溶胶可以被距离患者46厘米（18英寸）的工作人员吸入。在对体积中值直径（VMD）为8.5 μ m的流感病毒咳嗽气雾剂进行测试时，佩戴面罩可使工作人员在咳嗽后立即吸入暴露减少96%。面罩还将呼吸器的表面污染减少了97%。当使用较小的咳嗽气雾剂（VMD = 3.4 μ m）时，面罩的效果较差，仅阻挡了68%的咳嗽和76%的表面污染。在咳嗽后的1至30分钟内，气雾剂已分散在整个房间内，较大的颗粒已沉降，面罩仅使气雾剂吸入减少23%。将患者与工作人员之间的距离增加到183厘米（72英寸），咳嗽后立即发生的流感暴露减少了92%。我们的研究结果表明，卫生保健工作者可以吸入传染性空气中的颗粒，而治疗咳嗽病人。面罩可以大大减少医护人员短期暴露于大的传染性气溶胶颗粒，但较小的颗粒可以在空气中停留更长的时间，并更容易在面罩周围流动被吸入。因此，面罩为护理呼吸道感染患者的工作人员提供了有用的呼吸保护辅助。但是，当需要时，它们不能用作呼吸保护的替代品。[可提供本条的补充材料。请访问出版商在线版的《职业与环境卫生杂志》，获取以下免费补充资源：所进行实验的表格、有关气溶胶测量方法的更详细信息、实验装置的照片以及来自气溶胶测量设备、qPCR分析和VPA的实验数据摘要。
Health care workers are exposed to potentially infectious airborne particles while providing routine care to coughing patients. However, much is not understood about the behavior of these aerosols and the risks they pose. We used a coughing patient simulator and a breathing worker simulator to investigate the exposure of health care workers to cough aerosol droplets, and to examine the efficacy of face shields in reducing this exposure. Our results showed that 0.9% of the initial burst of aerosol from a cough can be inhaled by a worker 46 cm (18 inches) from the patient. During testing of an influenza-laden cough aerosol with a volume median diameter (VMD) of 8.5 μm, wearing a face shield reduced the inhalational exposure of the worker by 96% in the period immediately after a cough. The face shield also reduced the surface contamination of a respirator by 97%. When a smaller cough aerosol was used (VMD = 3.4 μm), the face shield was less effective, blocking only 68% of the cough and 76% of the surface contamination. In the period from 1 to 30 minutes after a cough, during which the aerosol had dispersed throughout the room and larger particles had settled, the face shield reduced aerosol inhalation by only 23%. Increasing the distance between the patient and worker to 183 cm (72 inches) reduced the exposure to influenza that occurred immediately after a cough by 92%. Our results show that health care workers can inhale infectious airborne particles while treating a coughing patient. Face shields can substantially reduce the short-term exposure of health care workers to large infectious aerosol particles, but smaller particles can remain airborne longer and flow around the face shield more easily to be inhaled. Thus, face shields provide a useful adjunct to respiratory protection for workers caring for patients with respiratory infections. However, they cannot be used as a substitute for respiratory protection when it is needed. [Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resource: tables of the experiments performed, more detailed information about the aerosol measurement methods, photographs of the experimental setup, and summaries of the experimental data from the aerosol measurement devices, the qPCR analysis, and the VPA.]