Morrell M J, Harty H R, Adams L, Guz A
Department of Medicine, Charing Cross and Westminster Medical School, London, United Kingdom.
J Appl Physiol (1985). 1996 Jul;81(1):274-81. doi: 10.1152/jappl.1996.81.1.274.
The increase in PCO2 that occurs during sleep may reflect an inadequate ventilatory compensation to an increase in upper airway resistance. To address this question in humans, we examined changes in breathing during wakefulness and non-rapid-eye-movement sleep in eight laryngectomized subjects who breathed through a tracheal stoma. In these subjects, any sleep-related increase in upper airway resistance could not affect ventilation. Healthy subjects breathing via an intact upper airway were studied as controls. The mean increase in end-tidal PCO2 from wakefulness to sleep was 2.7 +/- 2.6 (SD) Torr (P = 0.05) in laryngectomized subjects and 1.6 +/- 1.4 Torr (P = 0.02) in control subjects. During wakefulness, ventilation was lower in laryngectomized subjects compared with control subjects, although this difference was not statistically significant (6.8 +/- 1.9 vs. 7.4 +/- 1.2 l/min; P > 0.05). During sleep, the fall in ventilation was similar in the two groups (1.1 +/- 2.1 vs. 0.8 +/- 2.1 l/min; P > 0.05). Our observations are not consistent with the view that increases in upper airway resistance are obligatory for sleep-related CO2 retention in humans.
睡眠期间出现的PCO2升高可能反映了对上气道阻力增加的通气补偿不足。为了在人体中解决这个问题，我们研究了8名通过气管造口呼吸的喉切除受试者在清醒和非快速眼动睡眠期间的呼吸变化。在这些受试者中，任何与睡眠相关的上气道阻力增加都不会影响通气。以通过完整上气道呼吸的健康受试者作为对照。喉切除受试者从清醒到睡眠时呼气末PCO2的平均升高为2.7±2.6（标准差）托（P = 0.05），对照受试者为1.6±1.4托（P = 0.02）。在清醒期间，喉切除受试者的通气量低于对照受试者，尽管这种差异无统计学意义（6.8±1.9对7.4±1.2升/分钟；P>0.05）。在睡眠期间，两组的通气量下降相似（1.1±2.1对0.8±2.1升/分钟；P>0.05）。我们的观察结果与上气道阻力增加是人类睡眠相关二氧化碳潴留的必要条件这一观点不一致。
