咖啡因对犬膈肌疲劳的治疗作用

Curative effect of caffeine on canine respiratory muscle fatigue

用１４只实验犬观察咖啡因对膈肌疲劳的作用，以跨膈压曲线（ＰｄｉＦ曲线）作为评价膈肌收缩力的指标。膈肌疲劳模型用连续电刺激两侧膈神经的方法制备。结果：咖啡因（２０ｍｇ／ｋｇ）可显著增强疲劳后膈肌的收缩力，而且，咖啡因对膈肌的正性肌力作用与心输出量、肺总阻力及动态肺顺应性变化无关。作者讨论了咖啡因对膈肌肌力影响的可能机制。

The effect of intravenous caffeine on respiratory muscle fatigue was evaluated in 14 mongrel dogs.Diaphragmatic contractility was assessed by Pdifrequency curve and diaphragmatic fatigue was induced by continuous bilateral phrenic nerves stimulation.We found that caffeine (20mg/kg) significantly enhanced the contractility of the fatigued diaphragm in dogs,and this positive inotropic effect of caffeine was not due to its influence on cardiac output,total pulmonary resistance and dynamic pulmonary compliance.Our results suggest that caffeine might be a promising drug in the management of respiratory muscle fatigue in patients with chronic obstructive pulmonary disease.