Minowa Y, Ide T, Nishino T
Department of Anesthesiology, Graduate School of Medicine, Chiba University, 1-8-1 Inohanacho, chuo-ku, Chiba 260-8670, Japan.
Pulm Pharmacol Ther. 2002;15(4):363-8. doi: 10.1006/pupt.2002.0376.
We previously showed that inhaled furosemide improves experimentally induced dyspnea. In order to test the possibility that inhaled furosemide may alter the CO(2) chemosensitivity and thereby reduce the dyspneic sensation, the effect of inhaled furosemide on CO(2) chemosensitivity was evaluated with a double-blinded, randomized crossover design in 10 healthy subjects. The CO(2) chemosensitivity was measured by the steady-state and rebreathing methods before and after the inhalation of placebo (normal saline) and furosemide aerosols (40 mg). In addition, subjects were asked to rate their sensation of respiratory discomfort using a visual analog scale (dyspneic VAS) during the measurement of CO(2) chemosensitivity with the steady-state method. Our results showed that (1) inhaled furosemide does not affect the breathing patterns of resting breathing, (2) inhaled furosemide does not affect the slope and intercept of the CO(2) response curve, regardless of whether the CO(2) chemosensitivity is measured by the steady-state technique or rebreathing technique and (3) inhaled furosemide improves the dyspneic sensation produced during hypercapnic hyperpnea. These results suggest that the mechanism of the improvement of dyspnea by inhaling furosemide is not associated with the decrease in the ventilatory drive to CO(2).
我们之前表明吸入速尿可改善实验性诱发的呼吸困难。为了测试吸入速尿可能改变二氧化碳化学敏感性从而减轻呼吸困难感觉的可能性，我们采用双盲、随机交叉设计，在10名健康受试者中评估了吸入速尿对二氧化碳化学敏感性的影响。在吸入安慰剂（生理盐水）和速尿气雾剂（40毫克）前后，通过稳态法和重复呼吸法测量二氧化碳化学敏感性。此外，在使用稳态法测量二氧化碳化学敏感性期间，要求受试者使用视觉模拟量表（呼吸困难视觉模拟量表）对其呼吸不适感觉进行评分。我们的结果表明：（1）吸入速尿不影响静息呼吸的呼吸模式；（2）无论通过稳态技术还是重复呼吸技术测量二氧化碳化学敏感性，吸入速尿均不影响二氧化碳反应曲线的斜率和截距；（3）吸入速尿可改善高碳酸血症性通气过度期间产生的呼吸困难感觉。这些结果表明，吸入速尿改善呼吸困难的机制与对二氧化碳的通气驱动降低无关。
