Exhaled Air Dispersion Distances During Noninvasive Ventilation via Different Respironics Face Masks
Exhaled Air Dispersion Distances During Noninvasive Ventilation via Different Respironics Face Masks
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DOI：
10.1378/chest.09-0434
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发表时间：
2009-10-01
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.
背景资料：作为流感大流行防范工作的一部分，我们研究了两种不同口罩呼出的空气扩散距离和方向（Respironics; Murrysville，PA）在压力为-5 Pa的隔离室中进行无创正压通气（NPPV）期间连接到人类患者模拟器（HPS）。将HPS定位在床上45度，并编程模拟轻度肺损伤（耗氧量，300 mL/min;肺顺应性，35 mL/cm H2O。用肺内烟雾标记气流以便可视化。吸气气道正压通气（IPAP）从10 cm H2O开始，逐渐增加到18 cm H2O，而呼气压力维持在4 cm H2O。通过激光片光显示泄漏喷流羽流，并通过高清视频捕获图像。结果：随着IPAP从10 cm H2O增加到18 cm H2O，通过ComfortFull 2面罩（Respironics）在垂直于HPS头部的方向沿着正中矢状面的低标准化浓度的呼出空气从0.65 m增加到0.85 m。当通过图像3掩模施加10 cm H2O的IPAP时（Respironics）连接到耳语旋转，呼出的空气分散到0.95米朝向床的末端沿着正中矢状面，而更高的IPAP导致更广泛的传播更高浓度的烟雾。结论：患者通过ComfortFull 2面罩和Image 3面罩接受NPPV时，在1 m区域内大量暴露于呼出空气，后者的扩散泄漏更多，尤其是在较高的IPA-P下。（CHEST 2009; 136：998-1005）
Background: As part of our influenza pandemic preparedness, we studied the exhaled air dispersion distances and directions through two different face masks (Respironics; Murrysville, PA) attached to a human-patient simulator (HPS) during noninvasive positive-pressure ventilation (NPPV) in an isolation room with pressure of -5 Pa.Methods: The HPS was positioned at 45 degrees on the bed and programmed to mimic mild lung injury (oxygen consumption, 300 mL/min; lung compliance, 35 mL/cm H2O. Airflow was marked with intrapulmonary smoke for visualization. Inspiratory positive airway pressure (IPAP) started at 10 cm H2O and gradually increased to 18 cm H2O, whereas expiratory pressure was maintained at 4 cm H2O. A leakage jet plume was revealed by a laser light sheet, and images were captured by high definition video. Normalized exhaled air concentration in the plume was estimated from the light scattered by the smoke particles.Findings: As IPAP increased from 10 to 18 cm H2O, the exhaled air of a low normalized concentration through the ComfortFull 2 mask (Respironics) increased from 0.65 to 0.85 m at a direction perpendicular to the head of the HPS along the median sagittal plane. When the IPAP of 10 cm H2O was applied via the Image 3 mask (Respironics) connected to the whisper swivel, the exhaled air dispersed to 0.95 m toward the end of the bed along the median sagittal plane, whereas higher IPAP resulted in wider spread of a higher concentration of smoke.Conclusions: Substantial exposure to exhaled air occurs within a 1-m region, from patients rec eiving NPPV via the ComfortFull 2 mask and the Image 3 mask, with more diffuse leakage from the latter, especially at higher IPA-P. (CHEST 2009; 136:998-1005)