慢性阻塞性肺疾病与哮喘患者吸入支气管扩张剂后流速和容积反应的差异

Differences in gas flow rate and volume responses after inhalation of bronchodilator between patients with COPD and asthma

目的探讨慢性阻塞性肺疾病(COPD)和哮喘患者在支气管舒张试验中的流速和容积反应差异。方法纳入患者分为COPD组(295例)和哮喘组(577例),将其按吸入沙丁胺醇后第1秒用力呼气差FEV1变化值(ΔFEV1)每变化0.05L和用力肺活量FVC变化值(ΔFVC)每变化0.10L分别分层,分析ΔFEV1和ΔFVC的分布差异。将两组患者按吸入沙丁胺醇前FEV1占预计值的百分比(pre-BDFEV1%pred)每减少10%分层,分析支气管舒张试验阳性率和ΔFEV1、ΔFVC的差异,并分析ΔFEV1与ΔFVC的相关性。结果ΔFEV1在COPD组中呈近似正态分布,但在哮喘组中呈非正态分布,前者的分布范围小于后者。ΔFVC在两组的分布均呈近似正态分布。COPD组支气管舒张试验阳性率均低于哮喘组(P<0.001)。COPD组内部各层间ΔFEV1无显著差异,但哮喘组内部各层间差异显著(P<0.01)。两组患者的总ΔFEV1与ΔFVC呈正相关,但分层分析显示,pre-BDFEV1%pred为79.9～70.0和69.9～60.0时,COPD组的ΔFEV1与ΔFVC无相关性。结论COPD患者吸入支气管扩张剂后的流速反应和容积反应明显不同于哮喘患者,提示两组患者存在不同的病理和呼吸生理改变。

Objective To investigate the differences of gas flow rate and volume responses （△FEV1 and △FVC, respectively, calculated by subtracting pre-bronchodilator value from the corresponding salhutamol-induced post-bronchodilator value） after routine salbutamol reversibility testing between patients with chronic obstructive pulmonary disease （COPD） and asthma. Methods Patients digible for study were divided into COPD group （n=295） and asthma group （n 577）, which were stratified according to the reduction of 0. 05L in △FEV1, 0. 10L in AFVC, and 10 percent in FEV1 expressed as percentage of pre-bronchodilator value to its predicted value （pre-BD FEV1%pred）. Then, the percentage distributions of △FEV1 and AFVC were observed, the positive rates of salbutamol test were analyzed, the differences of △FEV1 and △FVC between the two groups were compared, and the correlation of △FEV1 and △FVC was evaluated. Results The △FEV1 presented proximate Gaussian distribution in COPD group, but abnormal distribution in asthma group, and the distribution area was sharper in COPD group than in asthma group. The △FVC presented proximate Gaussian distribution in both COPD and asthma group. The positive rates in salbutamol test were lower in COPD group than in asthma group （P〈0. 001）. No significant difference was detected among the 7 subgroups of △FEV1 in COPD group, while significant differences were found in asthma group （ P〈0. 01）. The direct correlation between total △FEV1 and total △FVC existed in both groups; however, the stratified analysis showed that there was no correlation between △FEV1 and AFVC in COPD group when pre-BD FEV1%pred ranged from 79. 9 to 70. 0 and from 69. 9 to 60. 0. Conclusion The gas flow rate and volume responses in patients with COPD differ from those with asthma after inhalation of bronchodilator, implying that different changes in pathophysiology and respiratory physiology exist in the two diseases.