Cao K Y, Berthon-Jones M, Sullivan C E, Zwillich C W
David Read Laboratory, Department of Medicine, University of Sydney, New South Wales, Australia.
J Appl Physiol (1985). 1993 Apr;74(4):1916-20. doi: 10.1152/jappl.1993.74.4.1916.
In humans the ventilatory [minute ventilation (VI)] response to sustained hypoxia is biphasic: an initial brisk increase followed by a decline is usually seen. However, in adult dogs, the ventilatory response to a similar stimulus shows no decline. To evaluate if central ventilatory drive is altered by sustained hypoxia, we measured the lowest ventilation (nadir) as the lowest moving average of seven sequential breaths within 200 s after transition to hyperoxia (100% O2) after 3 different exposures: room air, 4-min (brief) eucapnic hypoxia (arterial O2 saturation = approximately 80%), and 12-min (prolonged) eucapnic hypoxia. The nadir hyperoxic VI after brief hypoxia (2.7 +/- 0.2 l/min) was similar to that after room air (2.6 +/- 0.2 l/min; P > 0.05), with both less than prior room air mean VI (P < 0.05). The nadir after prolonged hypoxia (3.5 +/- 0.3 l/min) was significantly greater than that after brief hypoxia (P < 0.05). This suggests that central ventilatory drive increases in conscious dogs after sustained eucapnic hypoxia. The reason for the difference in central ventilatory response to hypoxia between conscious dogs and adult humans is unexplained.
在人类中，对持续性低氧的通气[分钟通气量(VI)]反应是双相的：通常先是迅速增加，随后下降。然而，成年犬对类似刺激的通气反应并未下降。为了评估持续性低氧是否会改变中枢通气驱动，我们在三种不同暴露后，测量了过渡到高氧(100% O2)后200秒内七个连续呼吸的最低移动平均值作为最低通气量(nadir)：室内空气、4分钟(短暂)等碳酸血症性低氧(动脉血氧饱和度约为80%)和12分钟(延长)等碳酸血症性低氧。短暂低氧后的最低高氧VI(2.7±0.2升/分钟)与室内空气后的相似(2.6±0.2升/分钟；P>0.05)，两者均低于先前室内空气的平均VI(P<0.05)。延长低氧后的nadir(3.5±0.3升/分钟)显著高于短暂低氧后的(P<0.05)。这表明在持续性等碳酸血症性低氧后，清醒犬的中枢通气驱动增加。清醒犬和成年人类对低氧的中枢通气反应存在差异的原因尚不清楚。
