Air hunger induced by acute increase in P-CO2 adapts to chronic elevation of P-CO2 in ventilated humans
Air hunger induced by acute increase in P-CO2 adapts to chronic elevation of P-CO2 in ventilated humans
复制标题
DOI：
10.1152/jappl.1996.81.2.949
复制
发表时间：
1996-08-01
影响因子：
3.3
通讯作者：
Banzett, RB
中科院分区：
文献类型：
--
作者：
BlochSalisbury, E;Shea, SA;Banzett, RB
动脉PCO2 （Pa-CO2）的短暂增加（持续几分钟）会产生呼吸不适感（空气饥饿）。尚不清楚空气饥饿是否适应Pa-CO2的慢性变化。本研究测试了引起空气饥饿所需的潮末PCO2 （PET(CO2)）水平是否会随着PET（CO2）的长期升高（持续数天）而增加。四名依赖呼吸机的受试者参加了一项为期两周的研究，在此期间，他们使用空气（安慰剂）或富含二氧化碳的空气（二氧化碳暴露）进行通气。对照期平均静息PET（CO2）为25 Torr（典型）；CO2暴露时PET（CO2）升高15 Torr。通气和动脉PO2在不同情况下没有差异。我们定期进行测试，让受试者评估由PET（CO2）短暂增加引起的空气饥饿强度。在二氧化碳暴露期间，引起给定空气饥饿等级所需的PET（CO2）的增加也增加了约15 Torr。也就是说，受试者的空气饥饿感觉完全适应了PET（CO2）的慢性增加。在二氧化碳暴露期间，动脉pH值没有完全恢复到控制值。空气饥饿感觉的化学感受器和神经通路的调节可以解释空气饥饿的适应性。
Brief increases in arterial PCO2 (Pa-CO2) (lasting several minutes) produce a sensation of respiratory discomfort (air hunger). It is not known whether air hunger adapts to chronic changes in Pa-CO2. This study tested whether the level of end-tidal PCO2 (PET(CO2)) required to evoke air hunger would increase with chronic elevation of PET(CO2) (lasting several days). Four ventilator-dependent subjects participated in a 2-wk study during which they were ventilated with air (placebo) or air rich in CO2 (CO2 exposure). Average resting PET(CO2) during control periods was 25 Torr (typical for such patients); PET(CO2) was 15 Torr higher during CO2 exposure. Ventilation and arterial PO2 did not differ between conditions. Periodically, we performed tests in which subjects rated the intensity of air hunger induced by brief increases in PET(CO2). The increase in PET(CO2) required to elicit a given air hunger rating during CO2 exposure also increased by similar to 15 Torr. That is, subjects' sensation of air hunger fully adapted to the chronic increase in PET(CO2). Arterial pH did not fully return to control values during CO2 exposure. Accommodation in the chemoreceptors and neural pathways that subserve air hunger sensation may explain the adaptation of air hunger.