Oral or nasal breathing? Real-time effects of switching sampling route onto exhaled VOC concentrations
Oral or nasal breathing? Real-time effects of switching sampling route onto exhaled VOC concentrations
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DOI：
10.1088/1752-7163/aa6368
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发表时间：
2017-06-01
影响因子：
3.8
通讯作者：
Trefz, Phillip
中科院分区：
文献类型：
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作者：
Sukul, Pritam;Oertel, Peter;Trefz, Phillip
呼吸挥发性有机化合物（VOC）的采样和分析需要标准化，以尽量减少普遍存在的混杂效应。生理因素可能掩盖浓度变化引起的病理生理效应。在人类中，在呼吸采样期间可能会发生口腔和鼻腔呼吸的无意识切换，这可能会影响VOC模式。在这里，我们研究了在切换呼吸途径时实时呼出的VOC浓度。在起搏呼吸（12次呼吸min（-1））期间，通过质子转移反应飞行时间质谱法连续分析15名健康志愿者的呼吸。每两分钟切换一次呼吸途径（设置1：口腔->鼻->口腔->鼻;设置2：口腔（进）鼻（出）->鼻（进）口腔（出）->口腔（进）鼻（出）->鼻（进）口腔（出））。定量监测吸入和肺泡空气中的VOC以及呼吸和血流动力学参数。呼吸路线和模式的改变会立即影响呼出的VOC浓度。这些变化在两种设置中均可重现。在设置-1心输出量和丙酮浓度保持恒定，而潮气末CO2分压（pET-CO2），异戊二烯和呋喃浓度反向反映潮气量和分钟通气量。H2S（硫化氢），C4 H8 S（烯丙基甲基硫醚），C3 H8 O（异丙醇）和C3 H6 O2在口腔呼气过程中增加。C4 H10 S在鼻呼气期间增加。在整个测量过程中，CH 2 O2稳定下降。在设置-2 pET-CO2，C2 H6 S（二甲基硫醚），异丙醇，柠檬烯和苯的浓度下降，而分钟通气，硫化氢和乙腈增加。异戊二烯和呋喃保持不变。呼吸途径和呼吸模式引起的VOC浓度变化取决于呼吸参数、口腔和鼻腔暴露以及化合物的理化性质。在使用呼吸VOC浓度作为生物标志物之前，必须在采样期间定义和严格监测呼吸模式。
There is a need for standardisation in sampling and analysis of breath volatile organic compounds (VOCs) in order to minimise ubiquitous confounding effects. Physiological factors may mask concentration changes induced by pathophysiological effects. In humans, unconscious switching of oral and nasal breathing can occur during breath sampling, which may affect VOC patterns. Here, we investigated exhaled VOC concentrations in real-time while switching breathing routes. Breath from 15 healthy volunteers was analysed continuously by proton transfer reaction time-of-flight mass spectrometry during paced breathing (12 breaths min(-1)). Every two minutes breathing routes were switched (Setup-1: Oral -> Nasal -> Oral -> Nasal; Setup-2: Oral(in)Nasal(out) -> Nasal(in)Oral(out) -> Oral(in)Nasal(out) -> Nasal(in)Oral(out)). VOCs in inspiratory and alveolar air and respiratory and hemodynamic parameters were monitored quantitatively in parallel. Changing of the breathing routes and patterns immediately affected exhaled VOC concentrations. These changes were reproducible in both setups. In setup-1 cardiac output and acetone concentrations remained constant, while partial pressure of end-tidal CO2 (pET-CO2), isoprene and furan concentrations inversely mirrored tidal-volume and minute-ventilation. H2S (hydrogen-sulphide), C4H8S (allyl-methyl-sulphide), C3H8O (isopropanol) and C3H6O2 increased during oral exhalation. C4H10S increased during nasal exhalations. CH2O2 steadily decreased during the whole measurement. In setup-2 pET-CO2, C2H6S (dimethyl-sulphide), isopropanol, limonene and benzene concentrations decreased whereas, minute-ventilation, H2S and acetonitrile increased. Isoprene and furan remained unchanged. Breathing route and patterns induced VOC concentration changes depended on respiratory parameters, oral and nasal cavity exposure and physico-chemical characters of the compounds. Before using breath VOC concentrations as biomarkers it is essential that the breathing modality is defined and strictly monitored during sampling.