慢性阻塞性肺病患者运动中生理死腔与潮气量比值变化

探讨慢性阻塞性肺病患者运动中生理死腔量及其与潮气量比值的变化与临床意义。方法无创性方法测定ＣＯＰＤ和健康对照者静息与运动时潮气末二氧化碳分压、自动计算出ＶＤ及ＶＤ／ＶＴ比值，结果：ＣＯＰＤ组运动能力与运动中最大通气量、最大摄氧量、最大潮气量、

Dead space/tidal volume ratio change during exercise in patients with COPD

Objective:To study the change in ratio of physiological dead space(VD) to tidal volume(VT) during exercise in patients with chronic obstructive pulmonary disease(COPD) and healthy controls.Methods:End tidal CO-2 pressures(PetCO-2) were measured with sensormedics NO.2900 system at rest and at the end of exercise in 20 COPD patients and 20 healthy controls.VD and VD/VT were calculated according to Jones' equation.Results:Maximal ventilation(VEmax),Maximal oxygen uptake(VO-2max),Maximal tidal volume(VTmax) and breathing reserve(BR) were lower in COPD group than those in control group( P <0.01).VD increased significantly at the end of exercise in both 2 groups,but the difference between the 2 groups either at rest or at the end of exercise were not significant.VD/VT ratio decreased significantly after exercise,in both groups the decrease was smaller in COPD group,made VD/VT significantly higher than that of the control group after exercise.The pH of arterial blood decreased significantly.Conclusions:The diffevence in changes of VD during exercise is not significant between the 2 groups.The abnormal response of VD/VT during exercise is mainly due to the restriction of VTmax.