Davidsson A, Naidu Sjöswärd K, Lundman L, Schmekel B
Department of Clinical Physiology, Institute of Medicine and Care, University Hospital, Linkoping, Sweden.
Respiration. 2005 Sep-Oct;72(5):529-36. doi: 10.1159/000087679.
Airway condition is presumably reflected in epithelial lining fluid (ELF). Exhaled breath condensate (EBC) has been used as a surrogate marker of the composition of ELF.
This study aimed at assessing the technical repeatability of chlorine measurements in EBC and comparing two separate condensators (Ecoscreen and R Tube regarding recovery and repeatability. Furthermore, the association between condensate recoveries and variations in the airway status were scrutinized.
EBC was collected using two condensators from 10 healthy volunteers. In addition, 13 asthmatic patients produced EBC with or without an added resistance of 5 cm H2O (Res5), applied to the outflow tract of Ecoscreen. All tests were done in random order. Chlorine levels (analyzed by a coulometric technique) in EBC served as a tool for investigation.
Chlorine was measurable in all samples. The coefficient of repeatability of chlorine measurements was <10%. Chlorine levels were higher in EBC obtained from R Tube (p < 0.001), and differences in recoveries and variability in chlorine levels were presumably related to technical differences in the condensators and not to the repeatability of chlorine measurements per se. Air-flow-dependent chlorine levels were obtained from healthy volunteers. Application of Res5, recruiting additional alveoli, resulted in increased recovery of the EBC volume, but not of chlorine, from those that had the most pronounced airway obstruction (p = 0.05).
We conclude that by employing a sensitive analysis technique, chlorine is repeatedly measurable in EBC. We suggest that the bulk of chlorine in EBC originates from large airways and not from the alveolar area. Both condensators were comparable regarding repeatability but differed regarding chlorine recovery.
气道状况可能反映在上皮衬液（ELF）中。呼出气冷凝物（EBC）已被用作ELF成分的替代标志物。
本研究旨在评估EBC中氯测量的技术可重复性，并比较两种不同的冷凝器（Ecoscreen和R管）在回收率和可重复性方面的表现。此外，还仔细研究了冷凝物回收率与气道状态变化之间的关联。
使用两种冷凝器从10名健康志愿者中收集EBC。此外，13名哮喘患者在Ecoscreen的流出道添加或不添加5 cm H2O的阻力（Res5）的情况下产生EBC。所有测试均按随机顺序进行。EBC中的氯水平（通过库仑法分析）用作研究工具。
所有样品中均可测量到氯。氯测量的可重复性系数<10%。从R管获得的EBC中氯水平更高（p < 0.001），回收率和氯水平变异性的差异可能与冷凝器的技术差异有关，而不是氯测量本身的可重复性。从健康志愿者中获得了气流依赖性氯水平。应用Res5，使更多肺泡参与，导致气道阻塞最明显的患者EBC体积回收率增加，但氯的回收率未增加（p = 0.05）。
我们得出结论，通过采用灵敏的分析技术，EBC中的氯可重复测量。我们认为EBC中的大部分氯源自大气道而非肺泡区域。两种冷凝器在可重复性方面相当，但在氯回收率方面存在差异。
