The effects of caffeine and theophylline on diaphragm contractility

摘要: The present study examined the effect of single, orally administered, doses caffeine (600 mg) on diaphragmatic muscle contractility in 6 normal subjects and compared magnitude with that theophylline. force-generating ability diaphragm was assessed from measurements transdiaphragmatic pressure (Pdi) obtained via catheters esophagus stomach, level excitation electromyogram recorded an esophageal electrode. Caffeine increased Pdi at all levels electromyographic activity subjects. Increases to generate were caused by increases rather than changes end-expiratory lung volume or thoracoabdominal configuration. Theophylline administered a dose equal 5 increase greater theophylline, however. theophylline not explained differences blood concentrations 2 drugs. Neither drug produced consistent heart rate. We conclude caffeine, which, like augments respiratory contractility, may prove useful treatment selected patients weakness.