Dispersion and Exposure to a Cough-Generated Aerosol in a Simulated Medical Examination Room
Dispersion and Exposure to a Cough-Generated Aerosol in a Simulated Medical Examination Room
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DOI：
10.1080/15459624.2012.725986
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发表时间：
2012-01-01
影响因子：
2
通讯作者：
Szalajda, Jonathan V.
中科院分区：
文献类型：
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作者：
Lindsley, William G.;King, William P.;Szalajda, Jonathan V.
很少有研究量化医疗环境中患者产生的潜在传染性生物气溶胶的扩散情况以及医护人员接触这些颗粒的情况。需要进行对照研究来评估生物气溶胶的传播以及不同类型的呼吸个人防护装备（PPE）在预防空气传播疾病传播方面的功效。配备了一个环境室来模拟患者将气溶胶颗粒咳入体检室，以及医护人员在暴露于这些颗粒的情况下呼吸。该系统由三个主要部分组成：（1）咳嗽模拟器，通过头部模型排出充满气溶胶的咳嗽； (2) 具有第二头型、可配备呼吸个人防护装备的呼吸模拟器； (3) 气溶胶颗粒计数器，用于测量个人防护装备内外以及整个房间内各个位置的浓度。评估了光学直径为 0.3 至 7.5 μm 的气溶胶颗粒的分散情况，以及呼吸频率、室内通风以及咳嗽和呼吸模拟器位置的影响。在 32 升/分钟和 85 升/分钟的流速下测量了咳嗽气溶胶颗粒通过放置在呼吸模拟器上的 9 种外科口罩和呼吸器模型的渗透性，并与标准过滤器测试仪的结果进行了比较。结果显示，咳嗽产生的气溶胶颗粒迅速扩散到整个房间，5 分钟内，房间内任何地方的工作人员都会接触到潜在危险的气溶胶。在没有个人防护装备的情况下，气溶胶暴露最高，其次是外科口罩，而在佩戴 N95 FFR 时，气溶胶暴露最少。无论呼吸速率以及咳嗽和呼吸模拟器的相对位置如何，都可以看到这些差异。这些结果可以更好地了解工作人员接触患者咳嗽气溶胶的情况以及不同类型呼吸个人防护装备的相对功效，并将帮助研究人员为医疗机构中有效的呼吸保护策略提供基于研究的建议。
Few studies have quantified the dispersion of potentially infectious bioaerosols produced by patients in the health care environment and the exposure of health care workers to these particles. Controlled studies are needed to assess the spread of bioaerosols and the efficacy of different types of respiratory personal protective equipment (PPE) in preventing airborne disease transmission. An environmental chamber was equipped to simulate a patient coughing aerosol particles into a medical examination room, and a health care worker breathing while exposed to these particles. The system has three main parts: (1) a coughing simulator that expels an aerosol-laden cough through a head form; (2) a breathing simulator with a second head form that can be fitted with respiratory PPE; and (3) aerosol particle counters to measure concentrations inside and outside the PPE and at locations throughout the room. Dispersion of aerosol particles with optical diameters from 0.3 to 7.5 mu m was evaluated along with the influence of breathing rate, room ventilation, and the locations of the coughing and breathing simulators. Penetration of cough aerosol particles through nine models of surgical masks and respirators placed on the breathing simulator was measured at 32 and 85 L/min flow rates and compared with the results from a standard filter tester. Results show that cough-generated aerosol particles spread rapidly throughout the room, and that within 5 min, a worker anywhere in the room would be exposed to potentially hazardous aerosols. Aerosol exposure is highest with no personal protective equipment, followed by surgical masks, and the least exposure is seen with N95 FFRs. These differences are seen regardless of breathing rate and relative position of the coughing and breathing simulators. These results provide a better understanding of the exposure of workers to cough aerosols from patients and of the relative efficacy of different types of respiratory PPE, and they will assist investigators in providing research-based recommendations for effective respiratory protection strategies in health care settings.