COPD病人一氧化碳弥散量与运动耐力、呼吸困难及通气效率的相关性研究

Correlation of carbon monoxide diffusion with exercise tolerance,dyspnea and ventilation efficiency in patients with chronic obstructive pulmonary disease

目的 探讨COPD病人一氧化碳弥散量(DLCO)与运动耐力、呼吸困难、通气效率的相关性。方法 入选60例稳定期COPD病人,根据单位肺泡容积的弥散量(DLCO/V_(A))将病人分为正常DLCO组和低DLCO组,收集2组静态肺功能、心肺运动试验(CPET)参数,并采用呼吸困难量表(mMRC)对呼吸困难进行评分。采用相关分析以及多重线性回归分析DLCO与运动耐力、呼吸困难、通气效率的相关性。结果 低DLCO组的一氧化碳弥散量占预计值百分比[(DLCO/V_(A))/pred]、最大功率负荷(Peak Load)、峰值摄氧量占预计值的百分比(Peak VO_(2)/pred)、每公斤体质量峰值摄氧量(Peak VO_(2)/kg)均低于正常DLCO组,无氧阈时CO_(2)通气当量(EQCO_(2)@AT)、mMRC评分均高于正常DLCO组,差异有统计学意义(P<0.01)。相关性分析显示,(DLCO/V_(A))/pred与Peak Load、Peak VO_(2)/pred、Peak VO_(2)/kg呈正相关,与EQCO2@AT、mMRC评分呈负相关(P<0.05)。多重线性回归分析结果显示,(DLCO/V_(A))/pred是预测COPD病人呼吸困难、运动耐力以及通气效率的独立预测因子(P<0.05)。结论 DLCO与COPD病人的呼吸困难、运动耐力、通气效率独立相关。

Objective To explore the correlation of diffusion of lung for carbon monoxide(DLCO) with exercise tolerance,dyspnea and ventilation efficiency in the patients with chronic obstructive pulmonary disease(COPD).Methods A total of sixty patients with stable COPD were divided into normal DLCO group and low DLCO group according to the results of diffusion capacity per unit alveolar volume(DLCO/V_(A)) in the first static pulmonary function examination at the time of enrollment.The static pulmonary function parameters of the two groups were collected and exercise tolerance,ventilation efficiency were tested by cardiopulmonary exercise test(CPET).The dyspnea scale(mMRC) was used to evaluate dyspnea.Pearson correlation analysis and liner regression were used to evaluate the correlation of DLCO with exercise tolerance,dyspnea and ventilation efficiency.Results The ratio of DLCO to predicted value [(DLCO/V_(A))/pred],Peak Load,peak oxygen uptake to predicted value(Peak VO_(2)/pred),peak oxygen uptake per kilogram of body weight(Peak VO_(2)/kg) in the low DLCO group were lower,while CO_(2) ventilation equivalent at anaerobic threshold( EQCO_(2)@AT),mMRC score were higher than those in the normal DLCO group(P<0.01).Correlation analysis showed(DLCO/V_(A))/pred was positively correlated with Peak Load,Peak VO_(2)/pred and Peak VO_(2)/kg,while EQCO_(2)@AT and mMRC score showed negative correlation with(DLCO/V_(A))/pred(P<0.05).Multiple linear regression analysis showed that(DLCO/V_(A))/pred was an independent predictor of respiratory distress,exercise endurance and ventilation efficiency in COPD patients(P<0.05).Conclusions DLCO is related to dyspnea,exercise endurance and ventilation efficiency in the patients with COPD.