Manning H L, Shea S A, Schwartzstein R M, Lansing R W, Brown R, Banzett R B
Department of Medicine, Beth Israel Hospital, Boston, MA.
Respir Physiol. 1992 Oct;90(1):19-30. doi: 10.1016/0034-5687(92)90131-f.
The act of breathing diminishes the discomfort associated with hypercapnia and breath-holding. To investigate the mechanisms involved in this effect, we studied the effect of tidal volume (VT) on CO2-evoked air hunger in 5 high-level quadriplegic subjects whose ventilatory capacity was negligible, and who lacked sensory information from the chest wall. Subjects were ventilated at constant frequency with a hyperoxic gas mixture, and end-tidal PCO2 was maintained at a constant but elevated level. VT was varied between the subjects' normal VT and a smaller VT. Subjects used a category scale to rate their respiratory discomfort or 'air hunger' at 30-40 sec intervals. In 4 of 5 subjects there was a strong inverse relationship between breath size and air hunger ratings. The quality of the sensation associated with reduced VT was nearly identical to that previously experienced with CO2 alone. We conclude that afferent information from the lungs and upper airways is sufficient to modify the sensation of air hunger.
呼吸行为可减轻与高碳酸血症和屏气相关的不适。为了研究这种效应所涉及的机制，我们对5名高位截瘫受试者进行了研究，这些受试者的通气能力可忽略不计，且胸壁缺乏感觉信息，我们研究了潮气量（VT）对二氧化碳诱发的空气饥饿感的影响。受试者用高氧混合气体以恒定频率进行通气，呼气末二氧化碳分压维持在恒定但升高的水平。VT在受试者的正常VT和较小的VT之间变化。受试者使用分类量表每隔30 - 40秒对其呼吸不适或“空气饥饿感”进行评分。在5名受试者中的4名中，呼吸量与空气饥饿感评分之间存在强烈的负相关关系。与减少VT相关的感觉质量与之前仅接触二氧化碳时所体验到的几乎相同。我们得出结论，来自肺部和上呼吸道的传入信息足以改变空气饥饿感。
