Immediate effects of breath holding maneuvers onto composition of exhaled breath
Immediate effects of breath holding maneuvers onto composition of exhaled breath
复制标题
DOI：
10.1088/1752-7155/8/3/037102
复制
发表时间：
2014-09-01
影响因子：
3.8
通讯作者：
Miekisch, Wolfram
中科院分区：
文献类型：
--
作者：
Sukul, Pritam;Trefz, Phillip;Miekisch, Wolfram
由于生理或病理生理效应而不是独特疾病生物标志物的出现而引起的浓度快速变化对呼吸研究的临床应用很重要。简单的动作，如屏气，可能会显著影响呼吸生物标志物浓度。在本研究中，实时评估不同屏气动作前后呼出的挥发性有机化合物（VOC）浓度。连续呼吸分辨测量（PTR-ToF-MS-8000）在31名健康受试者中以侧流采样模式进行。在1分钟的潮汐呼吸后，参与者屏住呼吸10、20、40、60秒，并尽可能长。之后，他们又正常呼吸了一分钟。通过将在线PTR-ToF-MS数据分配到呼吸的肺泡期或吸气期，可以实时监测VOC谱。在不同的屏气动作后，记录了呼出VOC浓度的突然而深刻的变化。屏气后10-20秒，VOC浓度恢复到基线水平。屏气引起的浓度变化取决于物质的物理化学性质。当物质浓度归一化到潮汐末CO2含量时，丙酮浓度的变化减小，而异戊二烯浓度的变化不受影响。由于呼吸方式对呼出物质浓度的影响取决于个别物质的性质，因此必须通过适当的实时分析来验证每种化合物的采样程序。将呼出浓度归一化到呼出的二氧化碳上，只对与二氧化碳具有相似物理化学性质的物质有效。
Rapid concentration changes due to physiological or pathophysiological effects rather than appearance of unique disease biomarkers are important for clinical application of breath research. Simple maneuvers such as breath holding may significantly affect breath biomarker concentrations. In this study, exhaled volatile organic compound (VOC) concentrations were assessed in real time before and after different breath holding maneuvers. Continuous breath-resolved measurements (PTR-ToF-MS-8000) were performed in 31 healthy human subjects in a side-stream sampling mode. After 1 min of tidal breathing participants held their breath for 10, 20, 40, 60 s and as long as possible. Afterwards they continued to breathe normally for another minute. VOC profiles could be monitored in real time by assigning online PTR-ToF-MS data to alveolar or inspired phases of breath. Sudden and profound changes of exhaled VOC concentrations were recorded after different breath holding maneuvers. VOC concentrations returned to base line levels 10-20 s after breath holding. Breath holding induced concentration changes depended on physico-chemical properties of the substances. When substance concentrations were normalized onto end-tidal CO2 content, variation of acetone concentrations decreased, whereas variations of isoprene concentrations were not affected. As the effects of breathing patterns on exhaled substance concentrations depend on individual substance properties, sampling procedures have to be validated for each compound by means of appropriate real-time analysis. Normalization of exhaled concentrations onto exhaled CO2 is only valid for substances having similar physico-chemical properties as CO2.