Schmidt D, Jörres R A, Magnussen H
Krankenhaus Grosshansdorf, Zentrum für Pneumologie und Thoraxchirurgie, LVA-Freie und Hansestadt Hamburg, Wöhrendamm 80, Grosshansdorf D-22927, Germany.
Eur J Med Res. 1997 Sep 29;2(9):384-8.
Several challenge procedures have been developed to characterize the cough reflex in patients with airway diseases. This study was performed to compare the interindividual range of cough sensitivity in asthmatic and normal subjects as well as smokers using an identical method. Sixteen normal subjects, 20 patients with mild bronchial asthma, 6 patients with moderate to severe bronchial asthma, 9 current smokers, and 7 occasional smokers were included. In all subjects, methacholine challenges and standardized citric acid challenges were performed. Sensitivity of the cough reflex was expressed as cough threshold, i.e., as concentration at which coughing occurred. Reproducibility was assessed in 23 subjects. Within a concentration range of 0.625-320.0 mg/ml, inhaled citric acid caused cough in all subjects. Geometric mean (range) cough threshold was 13 (2.5-160) in normal subjects, 14 (5-40) in patients with mild, and 32 (20-40) mg/ml in patients with moderate to severe asthma, 40 (20-80) in current smokers, and 119 (80-160) in occasional smokers. Cough thresholds were reproducible within one doubling concentration. In normal subjects and patients with mild bronchial asthma, thresholds were not significantly different from each other but lower than those of the other groups (p<0.05 each). Cough thresholds in smokers and patients with moderate to severe asthma did also not differ significantly and were lower than in occasional smokers (p<0.05). There was no significant correlation between cough threshold, baseline FEV subset1 , and methacholine responsiveness. Our data indicate that (1) subjects with mild asthma showed on average similar cough thresholds as normal subjects, (2) there was a large variation in cough thresholds within groups, (3) the reproducibility of cough thresholds was within one doubling concentration, (4) cough thresholds did not correlate with methacholine responsiveness or baseline airway tone. In view of the prevalence of cough as a symptom of bronchial asthma, it appears that the determination of citric acid-induced cough thresholds does not yield additional diagnostic information in these subjects.
已经开发了几种激发程序来表征气道疾病患者的咳嗽反射。本研究旨在使用相同的方法比较哮喘患者、正常受试者以及吸烟者之间咳嗽敏感性的个体间范围。纳入了16名正常受试者、20名轻度支气管哮喘患者、6名中度至重度支气管哮喘患者、9名当前吸烟者和7名偶尔吸烟者。对所有受试者进行了乙酰甲胆碱激发试验和标准化柠檬酸激发试验。咳嗽反射的敏感性用咳嗽阈值表示，即咳嗽发生时的浓度。对23名受试者评估了可重复性。在0.625 - 320.0 mg/ml的浓度范围内，吸入柠檬酸会使所有受试者咳嗽。正常受试者的几何平均（范围）咳嗽阈值为（2.5 - 160）mg/ml，轻度患者为14（5 - 40）mg/ml，中度至重度哮喘患者为32（20 - 40）mg/ml，当前吸烟者为40（20 - 80）mg/ml，偶尔吸烟者为119（80 - 160）mg/ml。咳嗽阈值在一个浓度翻倍范围内具有可重复性。在正常受试者和轻度支气管哮喘患者中，阈值彼此无显著差异，但低于其他组（每组p<0.05）。吸烟者和中度至重度哮喘患者的咳嗽阈值也无显著差异，且低于偶尔吸烟者（p<0.05）。咳嗽阈值与基线第1秒用力呼气容积（FEV₁）和乙酰甲胆碱反应性之间无显著相关性。我们的数据表明：（1）轻度哮喘患者的咳嗽阈值平均与正常受试者相似；（2）组内咳嗽阈值存在很大差异；（3）咳嗽阈值的可重复性在一个浓度翻倍范围内；（4）咳嗽阈值与乙酰甲胆碱反应性或基线气道张力无关。鉴于咳嗽作为支气管哮喘症状的普遍性，似乎测定柠檬酸诱导的咳嗽阈值在这些受试者中并未产生额外的诊断信息。
