Ip Margaret, Tang Julian W, Hui David S C, Wong Alexandra L N, Chan Matthew T V, Joynt Gavin M, So Albert T P, Hall Stephen D, Chan Paul K S, Sung Joseph J Y
Centre for Emerging Infectious Diseases, School of Public Health, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China.
Am J Infect Control. 2007 Dec;35(10):684-9. doi: 10.1016/j.ajic.2007.05.007.
Respiratory assist devices, such as oxygen masks, may enhance the potential to spread infectious aerosols from patients with respiratory infections.
A technique was developed to visualize exhaled aerosols during simulated patients' use of oxygen masks in a health care setting and tested using the simple, the nonrebreathing, and the Venturi oxygen masks. A smoke tracer was introduced into one of the lungs of the model to enable it to mix with the incoming oxygen and then to be further inhaled/exhaled by the model according to a variety of realistic respiratory settings (14, 24, and 30 breaths per minute, with tidal volumes of 500, 330, 235 mL, respectively) and oxygen supply flow rates (between 6 and 15 liters per minute). Digital recordings of these exhaled airflow patterns allowed approximate distances to be estimated for the extent of the visible exhaled air plumes emitted from each oxygen mask type at these settings.
It was found that the simple, the nonrebreathing, and the Venturi-type oxygen masks produced exhaled smoke plumes over minimum distances of 0.08 to 0.21 m, 0.23 to 0.36 m, and 0.26 to 0.40 m, respectively.
Health care workers may therefore consider any area within at least 0.4 m of a patient using such oxygen masks to be a potential nosocomial hazard zone.
呼吸辅助设备，如氧气面罩，可能会增加呼吸道感染患者传播感染性气溶胶的风险。
开发了一种技术，用于在医疗环境中模拟患者使用氧气面罩时可视化呼出的气溶胶，并使用简易氧气面罩、无重复呼吸氧气面罩和文丘里氧气面罩进行测试。将烟雾示踪剂引入模型的一侧肺，使其与进入的氧气混合，然后根据各种实际呼吸设置（每分钟14、24和30次呼吸，潮气量分别为500、330、235毫升）和氧气供应流速（每分钟6至15升）由模型进一步吸入/呼出。这些呼出气流模式的数字记录使得可以估计在这些设置下每种氧气面罩类型发出的可见呼出气流羽流范围的近似距离。
发现简易氧气面罩、无重复呼吸氧气面罩和文丘里型氧气面罩产生的呼出烟雾羽流的最小距离分别为0.08至0.21米、0.23至0.36米和0.26至0.40米。
因此，医护人员可能会认为，使用此类氧气面罩的患者周围至少0.4米范围内的任何区域都是潜在的医院感染危险区域。
