DISSOCIATION BETWEEN DYSPNEA AND RESPIRATORY EFFORT
DISSOCIATION BETWEEN DYSPNEA AND RESPIRATORY EFFORT
复制标题
DOI：
10.1164/ajrccm/146.5_pt_1.1222
复制
发表时间：
1992-11-01
期刊：
影响因子：
--
通讯作者：
SCHWARTZSTEIN, RM
中科院分区：
文献类型：
--
作者：
DEMEDIUK, BH;MANNING, H;SCHWARTZSTEIN, RM
高碳酸血症引起的呼吸困难可能与呼吸努力的感觉或CO2的中枢或外周效应有关。为了研究呼吸困难、呼吸努力和高碳酸血症之间的关系，我们研究了8名正常的幼稚受试者。通过使用视觉反馈系统，受试者保持50-60 L/min的恒定通气。PETCO 2在每次试验的前2 min（对照期）保持在40 mm Hg，然后在4 min（试验期）保持在40 mm Hg或升高至50 mm Hg。在每个控制和测试期结束时，要求受试者在50厘米视觉模拟量表上对呼吸困难（令人不快的呼吸冲动）和呼吸努力感（类似于举重）进行单独评级。高碳酸血症与努力等级显著降低（-7.3 +/-6.4，平均值+/- SD，p < 0.05）和伴随的呼吸困难增加（+ 6.6 +/-6.0，p < 0.05）相关。我们的结论是，呼吸困难与高碳酸血症是分离的呼吸努力的变化，二氧化碳有一个直接的中枢作用，导致呼吸困难。我们的数据还表明，当通气是呼吸的“反射”刺激而不是呼吸肌的“自愿”信号的结果时，在给定通气水平下的努力感较少。
Breathlessness induced by hypercapnia may be related to the sensation of respiratory effort or to the central or peripheral effects of CO2. To examine the relationship among breathlessness, respiratory effort, and hypercapnia, we studied eight normal naive subjects. By using a visual feedback system, subjects maintained a constant ventilation of 50-60 L/min. PETCO2 was held at 40 mm Hg during the first 2 min of each trial (control period), then for 4 min (test period) was either kept at 40 mm Hg or elevated to 50 mm Hg. At the end of each control and test period, subjects were asked to give separate ratings for dyspnea (an unpleasant urge to breathe) and for the sense of respiratory effort (analogous to lifting a weight) on a 50-cm visual analog scale. Hypercapnia was associated with a significant reduction in effort ratings (-7.3 +/- 6.4, mean +/- SD, p < 0.05) and a concomitant increase in dyspnea (+ 6.6 +/- 6.0, p < 0.05). We conclude that dyspnea associated with hypercapnia is dissociated from changes in respiratory effort, and that CO2 has a direct central effect that leads to breathlessness. Our data also suggest that the sense of effort at a given level of ventilation is less when the ventilation is the result of "reflex" stimuli to breathe rather than "voluntary" signals to the respiratory muscles.