Chang A B, Phelan P D, Roberts R G, Robertson C F
Dept of Thoracic Medicine, Royal Children's Hospital, Melbourne, Australia.
Eur Respir J. 1996 Nov;9(11):2220-3. doi: 10.1183/09031936.96.09112220.
Capsaicin has been used as a tussive agent in studies in adults to determine cough receptor sensitivity. The aim of this study was to determine the tolerance, repeatability and influence of inspiratory flow on the capsaicin cough receptor sensitivity test in children. Thirty children (mean age 11 yrs; range 6-16 yrs) were tested on two different days, to determine the lowest concentration of capsaicin required to stimulate two or more coughs (cough threshold (Cth)), 2-4 coughs (C2), and five or more coughs (C5). Capsaicin was nebulized through a dosimeter, with an arrangement that allowed the subjects to visualize and regulate their inspiratory flow. Using a constant inspiratory flow of 20 L x min(-1), tests were reproducible for C2, C5 and Cth (doubling dose changes of 1.13, 1.03 and 1.08, respectively). An increase in the inspiratory flow from 20 to 60 L x min(-1) significantly increased C2 (19.5 to 46.8 microM; p=0.016) and C5 (46.8 to 128.8 microM; p=0.008). We conclude that in children, the capsaicin cough challenge test: 1) is well-tolerated; 2) is highly repeatable; and that 3) the inspiratory flow significantly influences cough receptor sensitivity and repeatability of the test and should, thus, be regulated.
辣椒素已在成人研究中用作镇咳剂以确定咳嗽受体敏感性。本研究的目的是确定辣椒素咳嗽受体敏感性试验在儿童中的耐受性、可重复性以及吸气流量的影响。30名儿童（平均年龄11岁；范围6 - 16岁）在两个不同日期接受测试，以确定引发两次或更多次咳嗽（咳嗽阈值（Cth））、2 - 4次咳嗽（C2）以及五次或更多次咳嗽（C5）所需的最低辣椒素浓度。辣椒素通过剂量计雾化，其装置允许受试者可视化并调节吸气流量。使用20 L×min⁻¹的恒定吸气流量，C2、C5和Cth的测试具有可重复性（加倍剂量变化分别为1.13、1.03和1.08）。吸气流量从20 L×min⁻¹增加到60 L×min⁻¹会显著增加C2（从19.5 μM增加到46.8 μM；p = 0.016）和C5（从46.8 μM增加到128.8 μM；p = 0.008）。我们得出结论，在儿童中，辣椒素咳嗽激发试验：1）耐受性良好；2）具有高度可重复性；并且3）吸气流量会显著影响咳嗽受体敏感性和测试的可重复性，因此应加以调节。
