Exhaled Air and Aerosolized Droplet Dispersion During Application of a Jet Nebulizer
Exhaled Air and Aerosolized Droplet Dispersion During Application of a Jet Nebulizer
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DOI：
10.1378/chest.08-1998
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发表时间：
2009-03-01
期刊：
影响因子：
9.6
通讯作者：
Chan, Matthew T. V.
中科院分区：
文献类型：
--
作者：
Hui, David S.;Chow, Benny K.;Chan, Matthew T. V.
背景：作为流感大流行准备工作的一部分，我们研究了在正常肺状态和不同肺损伤严重程度的人体病人模拟器（HPS）上使用喷射雾化器时呼出的空气和雾化液滴的分散距离。方法：实验在医院隔离室进行，压力为- 5pa。气流以肺内烟雾为标志。射流喷雾器由空气以6 L/min的恒定流量驱动，掩膜池内充无菌水，通过雾化掩膜附着在HPS上。通过激光照射片和高清视频捕捉到的图像显示了泄漏的喷流。烟羽中的烟雾浓度是通过烟雾和液滴粒子散射的光来估计的。结果：在正常肺状态（耗氧量200 mL/min，肺顺应性70 mL/cm H2O）下，烟雾颗粒通过雾器侧通气孔的最大弥散距离为HPS侧0.45 m，轻度肺损伤（耗氧量300 mL/min，肺顺应性35 mL/cm H2O）时增大至0.54 m，重度肺损伤（耗氧量500 mL/min，肺顺应性10 mL/cm H2O）时超过0.8 m。更广泛的渗漏通过侧面喷雾器面罩的通风口被注意到更严重的肺损伤。解释：即使在负压隔离室内，卫生保健工作者也应在至少0.8米范围内采取额外的防护措施，以防止病因不明的发热性呼吸道疾病患者通过喷射雾化器接受治疗。
Background: As part of our influenza pandemic preparedness, we studied the dispersion distances of exhaled air and aerosolized droplets during application of a jet nebulizer to a human patient simulator (HPS) programmed at normal lung condition and different severities of lung injury.Methods: The experiments were conducted in a hospital isolation room with a pressure of - 5 Pa. Airflow was marked with intrapulmonary smoke. The jet nebulizer was driven by air at a constant flow rate of 6 L/min, with the mask reservoir filled with sterile water and attached to the HPS via a nebulizer mask. The exhaled leakage jet plume was revealed by a laser light sheet and images captured by high-definition video. Smoke concentration in the plume was estimated from the light scattered by smoke and droplet particles.Findings: The maximum dispersion distance of smoke particles through the nebulizer side vent was 0.45 m lateral to the HPS at normal lung condition (oxygen consumption, 200 mL/min; lung compliance, 70 mL/cm H2O), but it increased to 0.54 m in mild lung injury (oxygen consumption, 300 mL/min; lung compliance, 35 mL/cm H2O), and beyond 0.8 m in severe lung injury (oxygen consumption, 500 mL/min; lung compliance, 10 mL/cm H2O). More extensive leakage through the side vents of the nebulizer mask was noted with more severe lung injury.Interpretation: Health-care workers should take extra protective precaution within at least 0.8 m from patients with febrile respiratory illness of unknown etiology receiving treatment via a jet nebulizer even in an isolation room with negative pressure.