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目的本文探讨了最大呼气量对运动通气反应的影响。方法选择6名较高最大呼气量(FEV1>80%Pred;FEV1/FVC>72%)和5名较低最大呼气量(FEV1<80%Pred;FEV1/FVC<72%)者作为受试者。每名受试者尽最大力至疲劳,交替呼吸室内空气或含有3%CO2和76%N2的混合空气后用梯度循环测力仪进行测定。肺容量和流量环在每2min增加工作功率(20或30W)时进行测定,并对休息状态的数值进行分析。完成这两项测试后,分析通气阈(VTh)和最大运动值的最高等量工作率(HEWR)。结果在休息或VTh状态下呼吸CO2时,高流量者和低流量者的通气均增加(P<0.001)。呼吸CO2时,高流量者的HEWR增大(P<0.05)。而呼吸CO2时,如其对运动时的通气反应高于通气阈则使低流量者与呼吸室内空气者相比,其运动时的通气反应减少(P<0.05)。且吸入CO2运动时的通气反应高于通气阈者与FEV1(%Pred)(r=0.72,P<0.02)呈显著相关性。低流量者行最大运动的终末呼气肺容量和终末吸气肺容量在呼吸室内空气或CO2时较高,分别P<0.001、P<0.05。结论这些结果提示,低流量者吸入CO2来增强通气需求时,对较大或最大运动量的通气反应呈约束状态。这些结果可证实,高流量和低流量受试者在呼吸室内空气和3%CO2时的呼吸机制有显著性差别。
Objective This article explores the effect of maximum expiratory volume on exercise response. Methods Six patients with higher maximum expiratory volume (FEV1> 80% Pred; FEV1 / FVC> 72%) and five patients with lower maximum expiratory volume (FEV1 <80% Pred; FEV1 / FVC <72% The test. Each subject tried their best to be exhausted and exhausted, breathing air in the room or mixed air containing 3% CO2 and 76% N2, and then measured by a gradient cycle dynamometer. The lung volume and flow loop were measured every 2 min with increasing working power (20 or 30 W), and the values of rest were analyzed. After both tests were completed, the highest equivalent rate of ventilation (HEWR) was analyzed for both the ventilation threshold (VTh) and the maximum exercise value. Results Ventilation increased at both high and low flow rates at rest or VTh (P <0.001). When breathing CO2, HEWR was increased in high-flow participants (P <0.05). However, when breathing CO2, if the ventilatory response to exercise is higher than the ventilation threshold, the ventilatory response during exercise decreases compared with those with low flow rate (P <0.05). The ventilatory response during inhalation of CO2 was significantly higher than that of ventilatory threshold (FEV1% Pred (r = 0.72, P <0.02). The end-expiratory lung capacity and terminal aspiration lung volume of maximal exercise at low-flow rate were higher when breathing in air or CO2, P <0.001, P <0.05, respectively. Conclusions These results suggest that the ventilation response to greater or maximum exercise capacity is constrained when low-flow persons inhale CO2 to enhance ventilation requirements. These results confirm that there is a significant difference in breathing mechanisms between high-flow and low-flow subjects when breathing in room air and 3% CO2.