Tansley J G, Pedersen M E, Clar C, Robbins P A
University Laboratory of Physiology, University of Oxford, United Kingdom.
J Appl Physiol (1985). 1998 Feb;84(2):431-4. doi: 10.1152/jappl.1998.84.2.431.
Ventilation (VE) rises throughout 40 min of constant elevated end-tidal PCO2 without reaching steady state (S. Khamnei and P. A. Robbins. Respir. Physiol. 81: 117-134, 1990). The present study investigates 8 h of euoxic hypercapnia to determine whether VE reaches steady state within this time. Two protocols were employed: 1) 8-h euoxic hypercapnia (end-tidal PCO2 = 6.5 Torr above prestudy value, end-tidal PO2 = 100 Torr) followed by 8-h poikilocapnic euoxia; and 2) control, where the inspired gas was air. VE was measured over a 5-min period before the experiment and then hourly over a 16-h period. In the hypercapnia protocol, VE had not reached a steady state by the first hour (P < 0.001, analysis of variance), but there were no further significant differences in VE over hours 2-8 (analysis of variance). VE fell promptly on return to eucapnic conditions. We conclude that, whereas there is a component of the VE response to hypercapnia that is slow, there is no progressive rise in VE throughout the 8-h period.
在持续40分钟的呼气末PCO2持续升高过程中，通气量（VE）不断上升，但未达到稳态（S. Khamnei和P. A. Robbins。呼吸生理学。81: 117 - 134, 1990）。本研究调查了8小时的常氧性高碳酸血症，以确定VE在此期间是否达到稳态。采用了两种方案：1）8小时常氧性高碳酸血症（呼气末PCO2比研究前值高6.5 Torr，呼气末PO2 = 100 Torr），随后是8小时的变碳酸性常氧；2）对照组，吸入气体为空气。在实验前5分钟测量VE，然后在16小时内每小时测量一次。在高碳酸血症方案中，到第一小时VE尚未达到稳态（方差分析，P < 0.001），但在第2 - 8小时VE没有进一步的显著差异（方差分析）。恢复到正常碳酸血症状态时，VE迅速下降。我们得出结论，虽然VE对高碳酸血症的反应有一个缓慢的成分，但在整个8小时期间VE没有逐渐上升。
