Optimisation of sampling parameters for standardised exhaled breath sampling
Optimisation of sampling parameters for standardised exhaled breath sampling
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DOI：
10.1088/1752-7163/aa8a46
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发表时间：
2018-01-01
影响因子：
3.8
通讯作者：
Hanna, George B.
中科院分区：
文献类型：
--
作者：
Doran, Sophie L. F.;Romano, Andrea;Hanna, George B.
呼吸采样缺乏标准化是导致结果重复性差的主要因素，因此是临床实践中采用呼吸测试的障碍。在线和袋呼吸采样具有优势，但不适合多中心临床研究，而存储和稳健的运输是进行大规模研究的必要条件。已经开发了几种装置来控制采样参数，并将挥发性有机化合物（VOC）浓缩到热解吸（TD）管上，随后将这些管运送到实验室分析。我们进行了三个实验来研究（i）呼吸采样的分数（全呼气与低呼气呼出气）;（ii）呼吸样本体积（125、250、500和1000 ml）;和（iii）呼吸样本流速（400、200、100和50 ml min（-1））。目标挥发性有机物是丙酮和潜在的挥发性生物标志物的食管-胃癌属于醛，脂肪酸和酚类化学类别。我们还研究了收集执行时间和环境污染的影响。实验表明，呼出气采样装置的使用需要选择最佳的采样参数。样品量的增加提高了检测到的挥发性有机化合物的水平。然而，呼出气的分数和流速的影响取决于所测量的目标VOC。食管-胃癌的潜在挥发性生物标志物的浓度在全呼吸道和下呼吸道呼出气之间没有显著差异。虽然酚类和丙酮的回收率较低时，呼吸采样在较高的流速进行，其他挥发性有机物不受影响。专用的“清洁空气供应”减少了来自环境空气的污染，但呼吸收集装置本身可能是污染物的来源。在临床研究中使用挥发性有机化合物引发胃食管癌的潜在生物标志物，最佳参数是500毫升的样品体积的整个呼吸与流速为200毫升/分钟（-1）。
The lack of standardisation of breath sampling is a major contributing factor to the poor repeatability of results and hence represents a barrier to the adoption of breath tests in clinical practice. On-line and bag breath sampling have advantages but do not suit multicentre clinical studies whereas storage and robust transport are essential for the conduct of wide-scale studies. Several devices have been developed to control sampling parameters and to concentrate volatile organic compounds (VOCs) onto thermal desorption (TD) tubes and subsequently transport those tubes for laboratory analysis. Weconducted three experiments to investigate (i) the fraction of breath sampled (whole versus lower expiratory exhaled breath); (ii) breath sample volume (125, 250, 500 and 1000 ml); and (iii) breath sample flow rate (400, 200, 100 and 50 ml min(-1)). The target VOCs were acetone and potential volatile biomarkers for oesophago-gastric cancer belonging to the aldehyde, fatty acids and phenol chemical classes. Wealso examined the collection execution time and the impact of environmental contamination. The experiments showed that the use of exhaled breath-sampling devices requires the selection of optimum sampling parameters. The increase in sample volume has improved the levels of VOCs detected. However, the influence of the fraction of exhaled breath and the flow rate depends on the target VOCs measured. The concentration of potential volatile biomarkers for oesophago-gastric cancer was not significantly different between the whole and lower airway exhaled breath. While the recovery of phenols and acetone fromTDtubes was lower when breath sampling was performed at a higher flow rate, other VOCs were not affected. A dedicated 'clean air supply' reduces the contamination from ambient air, but the breath collection device itself can be a source of contaminants. In clinical studies using VOCs to elicit potential biomarkers of gastro-oesophageal cancer, the optimum parameters are 500 mls sample volume of whole breath with a flow rate of 200 ml min(-1).