成人哮喘患者对支气管扩张剂的反应性不能预测支气管高反应性
2009/08/11
背景：对于肺活量正常的可疑哮喘患者，给予支气管扩张剂（BD）能改善呼气流速。但此现象在成人中的预测价值尚不清楚。
目的：本研究评价患者对BD的反应在乙酰甲胆碱激发试验（MCT）检测支气管高反应性中的预测价值。
患者与方法：研究人群包括62名非吸烟成人患者（41.9%女性），年龄29.5±15.5岁（18～64岁），入选者为肺活量正常的可疑哮喘患者，入选试验1周内进行过MCT试验。将导致第1秒用力呼气体积（FEV1）下降20％（PC20）时的乙酰甲胆碱浓度（4和8 mg/mL）作为预测界值，对MCT阳性和阴性患者对BD的反应性（吸入200 mu g沙丁胺醇）进行比较。
结果：在基线状态下平均FEV1（±SD）为预测值的87.8±12%。给予BD后，FEV1平均增加4.3±3.9%。对于4 mg/mL和8 mg/mL乙酰甲胆碱，其PC20的BHR发生率分别为17.7%和25.8%。对于MCT检测阳性和阴性患者，给予BD后FEV1分别为3.9%±3.3%和4.4%±4.1%（预测界值为4 mg/mL，P = 0.89）预测值；当预测界值采用8 mg/ml时，相应的数值分别为4.3%±3.1%和4.3%±4.2%（P = 0.8465）。对于MCT阳性患者，采用上述预测界值时，给予BD后FEV1的增加值与PC20之间未见相关性（相关系数和P值分别为：r = 0.1645, P = 0.6289；r = 0.2417,P = 0.4051）。
结论：对于肺活量正常的疑似哮喘患者，对BD的反应性不能用于预测支气管高反应性。
（林江涛 审校）
Fruchter O, et al. J Asthma. 2009 Jun;46(5):455-459.
The response to bronchodilators in adults is not predictive of bronchial-hyperreactivity.
Fruchter O, Hardak E, Yigla M.
Division of Pulmonary Medicine, Rambam Health Care Campus, Technion, Institute of Technology, Haifa, Israel.
BACKGROUND: In some subjects with suspected asthma who have normal spirometry, administration of bronchodilators (BD) improves expiratory flow rates. The predictive value of this phenomenon in adults is not known.
OBJECTIVES: To evaluate the predictive value of the response to BD for bronchial hyper-responsiveness (BHR) using the metacholine challenge test (MCT). Patients and methods. The study population included 62 non-smoking adult patients (41.9% women) 29.5 +/- 15.5 years of age (range 18-64 years) with suspected asthma with normal spirometry that underwent MCT within 1 week. The response to BD (200 mu g inhaled salbutamol) was compared between subjects with positive and negative MCT using cutoff levels of provocative concentrations of metacholine causing a 20% decrease in forced expiratory volume in 1 second (FEV(1)) (PC(20)) of 4 and 8 mg/mL.
RESULTS: Mean (+/- SD) baseline FEV(1) was 87.8 +/- 12% of predicted. After BD administration the mean FEV(1) increased by 4.3 +/- 3.9%. The prevalence of BHR was 17.7% and 25.8% for PC(20) for PC(20) of 4 mg/mL and 8 mg/mL, respectively. The post-BD FEV(1) increment for subjects with positive and negative MCT tests was 3.9% +/- 3.3% versus 4.4% +/- 4.1%, respectively; p = 0.89, using cutoff of 4 mg/mL. The corresponding figures for cutoff of 8 mg/ml were 4.3% +/- 3.1% vs. 4.3% +/- 4.2%, respectively; p = 0.8465. There was no correlation between post-BD FEV(1) increment and PC(20) values in patients with positive MCT test for the above-mentioned cutoff levels (correlation coefficient r = 0.1645, p = 0.6289; and r = 0.2417, p = 0.4051, respectively).
CONCLUSIONS: In adults with suspected asthma who have normal spirometry, the response to BD cannot be used to predict BHR.
