Stone R A, Barnes P J, Chung K F
Dept of Thoracic Medicine, National Heart and Lung Institute, London, UK.
Eur Respir J. 1993 Jun;6(6):862-7.
We studied the tussive effects of a chloride-deficient solution (1.26% sodium bicarbonate). Nine normal volunteers and 10 mild asthmatic subjects were studied. In two double-blind, placebo-controlled, cross-over studies, we assessed the profile of any inhibitory effects that inhaled frusemide had over these responses. Baseline cough challenge was followed by inhalation of either frusemide (40 mg), or 0.15 M NaCl control. Cough was then induced at 0.5, 2, 4 and 6 h after treatment. Forced expiratory volume in one second (FEV1) was measured before and after each challenge. Changes from the baseline cough response due to drug or control were compared nonparametrically at each time point. There was no difference in the sensitivity of normal and asthmatic subjects to the cough challenge (median cough response 15 and 14.5 on control day, 12 and 15 on frusemide day). Frusemide caused sustained inhibition of the cough response in normal subjects (p < 0.05 at 2 h, p < 0.01 at 4 h), but had only a small, nonsignificant effect in asthmatic subjects at 30 min. Falls in FEV1 of asthmatic subjects due to the chloride-deficient solution were not significant, and did not correlate with number of coughs. We conclude that mild asthmatic subjects are less sensitive than normal subjects to the influence of frusemide against low chloride challenge. This observation is not explained by bronchoconstrictor effects of the cough challenge in asthmatic subjects.
我们研究了一种缺氯溶液（1.26%碳酸氢钠）的镇咳作用。研究对象包括9名正常志愿者和10名轻度哮喘患者。在两项双盲、安慰剂对照的交叉研究中，我们评估了吸入速尿对这些反应的任何抑制作用特征。在进行基线咳嗽激发试验后，分别吸入速尿（40毫克）或0.15M氯化钠对照液。然后在治疗后0.5、2、4和6小时诱发咳嗽。在每次激发试验前后测量一秒用力呼气量（FEV1）。在每个时间点，对药物或对照引起的基线咳嗽反应变化进行非参数比较。正常受试者和哮喘患者对咳嗽激发试验的敏感性没有差异（对照日的中位数咳嗽反应分别为15和14.5，速尿日为12和15）。速尿可使正常受试者的咳嗽反应持续受到抑制（2小时时p<0.05，4小时时p<0.01），但在哮喘患者中，30分钟时只有微小的、无统计学意义的作用。缺氯溶液导致哮喘患者的FEV1下降不显著，且与咳嗽次数无关。我们得出结论，轻度哮喘患者对速尿抵抗低氯激发的影响比正常受试者不敏感。哮喘患者咳嗽激发试验的支气管收缩作用无法解释这一观察结果。
