Changes in cardiac output during sustained maximal ventilation in humans.
Changes in cardiac output during sustained maximal ventilation in humans.
复制标题
人类持续最大通气期间心输出量的变化。
DOI：
10.1152/jappl.1987.63.1.181
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Ramanathan,M
中科院分区：
文献类型：
--
作者：
Anholm,JD;Johnson,RL;Ramanathan,M
为了确定从安静呼吸到最大持续通气的心输出量和耗氧量（Vo 2）的增量，使用乙炔再呼吸技术测量了5名受试者的Vo 2和心输出量。在静息和持续最大通气期间多次测量每例受试者的心输出量和Vo 2。在最大通气量期间，受试者呼吸5% CO2以防止低碳酸血症。从静息到最大呼吸的心输出量增加被视为呼吸肌血流量的估计值，并用于根据Fick方程计算呼吸肌间的动静脉O2含量差异。最大通气量范围为127 - 193 l/min时，心输出量增加4.3 +/- 1.0 l/min（平均值+/- SD），从静息时的5.6 +/- 0.7 l/min增加至9.9 +/- 1.1 l/min。最大通气量期间，Vo 2从312 +/- 29 ml/min增加至723 +/- 69 ml/min。最大呼吸期间呼吸肌的O2提取为9.6 +/- 1.0 vol%（范围8.5 - 10.7 vol%）。这些值表明在无负荷最大持续通气期间呼吸肌血流量的上限为3-5 l/min。
To determine the increment in cardiac output and in O2 consumption (Vo2) from quiet breathing to maximal sustained ventilation, Vo2 and cardiac output were measured using an acetylene rebreathing technique in five subjects. Cardiac output and Vo2 were measured multiple times in each subject at rest and during sustained maximal ventilation. During maximal ventilation subjects breathed 5% CO2 to prevent hypocapnia. The increase in cardiac output from rest to maximal breathing was taken as an estimate of respiratory muscle blood flow and was used to calculate the arteriovenous O2 content difference across the respiratory muscles from the Fick equation. Cardiac output increased by 4.3 +/- 1.0 l/min (mean +/- SD), from 5.6 +/- 0.7 l/min at rest to 9.9 +/- 1.1 l/min, during maximal ventilations ranging from 127 to 193 l/min. Vo2 increased from 312 +/- 29 to 723 +/- 69 ml/min during maximal ventilation. O2 extraction across the respiratory muscles during maximal breathing was 9.6 +/- 1.0 vol% (range 8.5 to 10.7 vol%). These values suggest an upper limit of respiratory muscle blood flow of 3–5 l/min during unloaded maximal sustained ventilation.