The effect of maintenance theophylline therapy on lung work in severe chronic obstructive pulmonary disease while standing and walking.

摘要: There is controversy whether routine use of theophylline warranted in chronic obstructive pulmonary disease (COPD). Effects on spirometry are minimal, and subjective relief difficult to document. Therefore, we undertook study the effects theophyline using a functional approach, namely, its lung mechanics standing or walking patient. In double blind, placebo controlled crossover study, 400 mg slow-release (TheoDur) were given twice day 13 trials 10 patients with severe COPD. Lung calculated breath-by-breath basis by computer from esophageal pressures flow. Expired volumes simultaneously collected. Spirometry was then performed. On limb, spirometric response 0.5 terbutaline subcutaneously compared response. At mean serum level 12.3 micrograms/ml, produced entire group reduction work breathing done (WL) 16% (p less than 0.002) while walking, but significant effect not detected. During both standing, resistance (RL) 15 0.002). Minute volume (VE) increased at borderline significance, 19% ratio WL VE individual patient, changes influenced more RL; fact, correlated best product (VE)2 RL. Theophylline increase 15% forced expiratory one second (FEV1) vital capacity (FVC).(ABSTRACT TRUNCATED AT 250 WORDS)