Banzett R B, Lansing R W, Brown R, Topulos G P, Yager D, Steele S M, Londoño B, Loring S H, Reid M B, Adams L
Department of Environmental Science and Physiology, Harvard School of Public Health, Boston, Massachusetts 02115.
Respir Physiol. 1990 Jul;81(1):1-17. doi: 10.1016/0034-5687(90)90065-7.
The tolerance of totally curarized subjects for prolonged breath hold is viewed by many as evidence that respiratory muscle contraction is essential to generate the sensation of breathlessness. Although conflicting evidence exists, none of it was obtained during total neuromuscular block. We completely paralyzed four normal, unsedated subjects with vecuronium (a non-depolarizing neuromuscular blocker). Subjects were mechanically ventilated with hyperoxic gas mixtures at fixed rate and tidal volume. End-expiratory PCO2 (PETCO2) was varied surreptitiously by changing inspired PCO2. Subjects rated their respiratory discomfort or 'air hunger' every 45 sec. At low PETCO2 (median 35 Torr) they felt little or no air hunger. When PETCO2 was raised (median 44 Torr) all subjects reported severe air hunger. They had reported the same degree of air hunger at essentially the same PETCO2 before paralysis. When questioned afterwards all subjects said the sensation could be described by the terms 'air hunger', 'urge to breathe', and 'shortness of breath', and that is was like breath holding. They reported no fundamental difference in the sensation before and after paralysis. We conclude that respiratory muscle contraction is not important in the genesis of air hunger evoked by hypercapnia.
许多人认为，完全箭毒化的受试者对长时间屏气的耐受性证明呼吸肌收缩对于产生呼吸急促感至关重要。尽管存在相互矛盾的证据，但这些证据均未在完全神经肌肉阻滞期间获得。我们用维库溴铵（一种非去极化神经肌肉阻滞剂）使4名正常、未使用镇静剂的受试者完全麻痹。受试者通过固定频率和潮气量的高氧气体混合物进行机械通气。通过改变吸入的PCO2来悄悄改变呼气末PCO2（PETCO2）。受试者每45秒对其呼吸不适或“空气饥饿感”进行评分。在低PETCO2（中位数35托）时，他们几乎没有或没有空气饥饿感。当PETCO2升高（中位数44托）时，所有受试者均报告有严重的空气饥饿感。在麻痹前，他们在基本相同的PETCO2时报告了相同程度的空气饥饿感。之后接受询问时，所有受试者表示这种感觉可用“空气饥饿感”、“呼吸冲动”和“呼吸急促”来描述，并且类似于屏气。他们报告麻痹前后的感觉没有根本差异。我们得出结论，呼吸肌收缩在高碳酸血症诱发的空气饥饿感的产生中并不重要。
