【摘要】 目的　评价死腔负荷对肺通气功能和呼吸肌的影响 ,测试呼吸肌氧耗的检测方法 ,探讨呼吸肌氧耗在慢性阻塞性肺疾病 (COPD)运动耐力下降中的作用。方法　 2 6例中度COPD患者和2 9名年龄相近健康对照者在 30 0ml呼吸管路死腔 (长 4 6cm)负荷下 ,完成 30W或 5 5W功率恒定运动试验 ,并在死腔负荷下检测运动前、后肺功能和运动中分钟通气量 (V·E)和摄氧量 (V· O2 )。结果无论COPD或健康对照组 ,在静息状态或运动后 ,增加死腔对用力肺活量 (FVC)、一秒钟用力呼气容积(FEV1)和FEV1/FVC无显著影响。COPD组静息死腔负荷下FVC、FEV1和FEV1/FVC分别为 (3 0 3±0 15 )L、(1 95± 0 0 9)L和 (6 4 9± 2 .5 ) % ;5 5W运动后上述指标分别为 (3 0 3± 0 18)L、(2 0 0± 0 13)L和 (6 6 3± 3 2 ) % (P均 >0 0 5 )。每例受试个体 ,无论静息或运动中 ,附加死腔均导致V·E 和V·O2 在原有基础上显著增加 ,卸除死腔后V·E 和V·O2 回落。死腔负荷下V· O2 的增加量 (ΔV· O2 )在静息和 30W运动时 ,COPD组和健康对照组之间差异无显著性。在 5 5W运动时 ,COPD组ΔV·O2 显著高于健康对照组 [(2 72± 2 4 )ml/min与 (194± 19)ml/min ,P <0 0 5 ]。结论　本组患者呼吸管路加长 4 6cm(30 0ml死腔 ) ,伴随中等强度运动?更多还原

【Abstract】 Objective To evaluate the effect of dead space(V D) loading on ventilation and respiratory muscle function,to test a novel measurement of oxygen consumption of respiratory muscle,and to analyze the effect of oxygen consumption of respiratory muscle on exercise performance. Methods Twenty-six patients with moderate chronic obstructive pulmonary disease(COPD) and 29 age-matched healthy control subjects underwent 30 W or 55 W constant work(CW) exercise in a standard protocol and under 300 ml (46 cm in length) dead space loading. Pulmonary function test(PFT) was measured pre- and post- exercise both in the dead space loading and unloading. Results The addition of 300 ml V D did not significantly affect FVC,FEV 1,and FEV 1/FVC in both COPD patients and the healthy controls at rest or after CW exercise. The values of FVC,FEV 1,and FEV 1/FVC with V D loading in COPD were (3.03±0.15)L, (1.95±0.09)L and (64.9±2.5)%,respectively;after 55 W CW exercise,those values were (3.03±0.18)L,(2.00±0.13)L,and (66.3±3.2)%,respectively(P>0.05). Minute ventilation( V · E) and oxygen uptake( V ·O 2) significantly went up with V D loading and dropped with unloading at rest and during exercise in every subject. The enhancement of V ·O 2 under V D loading(Δ V ·O 2) was not significantly different between COPD and the control at rest or during lower intensity CW(30 W) exercise. However,Δ V ·O 2 was significantly higher in COPD than in the control during moderate intensity CW(55 W) exercise[(272±24)ml/min vs (194±19)ml/min,P<0.05]. Conclusions Lengthening respiratory tube to 46 cm(300 ml dead space) combined with moderate constant work exercise does not worsen the airflow obstructive in COPD,or results in respiratory muscle fatigue both in the COPD patients and the healthy controls. The enhancement of V ·O 2 under V D loading can be considered as oxygen consumption of respiratory muscle working for increased ventilation. An advantage of oxygen consumption in respiratory muscle during moderate intensity exercise in COPD implies that maintaining the balance of oxygen supplying to both respiratory and limb muscles might be the key point in performing moderate to heavy exercise.更多还原