Nejla S, Fujimura M, Kamio Y
Division of Chest Diseases, Cancer Research Hospital, Ankara, Turkey.
Respirology. 2000 Dec;5(4):337-42.
Dosimeter method and tidal breathing method have been used to assess cough sensitivity to inhaled capsaicin, a C-fibre ending stimulator. The aim of the present study was to evaluate the repeatability of and the agreement between the two methods.
Cough threshold, the lowest concentration of capsaicin causing five or more coughs, was measured twice 1-3 weeks apart by each method in 26 normal subjects. Increasing concentrations of capsaicin were inhaled by a single breath in the dosimeter method or by 15 s tidal breathing in the tidal breathing method in 1 min intervals.
Coefficients of repeatability of the cough threshold measurement were 1.89 and 2.71 doubling concentration in the tidal breathing method and the dosimeter method, respectively, suggesting good repeatability in the cough threshold measurement by both methods. The cough threshold was significantly (P < 0.0001) greater by 1.75 doubling concentration on the dosimeter method than the tidal breathing method. The coefficient of agreement between the two methods was 2.53 doubling concentration. Five subjects complained of burning sensation in the throat in the dosimeter method but no patient complained about the tidal breathing method (P < 0.05).
Although the agreement between the two methods was considered to be good, higher concentrations of capsaicin solution were required to determine the cough threshold in the dosimeter method, resulting in an unpleasant sensation in the throat.
剂量计法和潮气呼吸法已被用于评估对吸入辣椒素（一种C纤维末梢刺激剂）的咳嗽敏感性。本研究的目的是评估这两种方法的可重复性及一致性。
在26名正常受试者中，每种方法间隔1 - 3周测量两次咳嗽阈值（引起5次或更多次咳嗽的辣椒素最低浓度）。剂量计法中，以1分钟的间隔单次呼吸吸入递增浓度的辣椒素；潮气呼吸法中，以15秒的潮气呼吸方式吸入递增浓度的辣椒素。
潮气呼吸法和剂量计法测量咳嗽阈值的重复性系数分别为1.89和2.71倍浓度增加，表明两种方法测量咳嗽阈值均具有良好的重复性。剂量计法测得的咳嗽阈值比潮气呼吸法显著高1.75倍浓度增加（P < 0.0001）。两种方法之间的一致性系数为2.53倍浓度增加。剂量计法中有5名受试者抱怨喉咙有烧灼感，但潮气呼吸法中无受试者抱怨（P < 0.05）。
虽然两种方法之间的一致性被认为良好，但剂量计法测定咳嗽阈值需要更高浓度的辣椒素溶液，导致喉咙出现不适感。
