Nebulized fenoterol and i.v. aminophylline in acute severe asthma

We investigated the bronchodilator effect of intravenous aminophylline given after a cumulative dose of nebulized fenoterol of 2.4 mg in 18 patients with acute severe asthma. The mean forced expiratory volume in 1 s (FEV1) +/- SD before treatment was 0.72 +/- 0.22 l. The mean improvement in FEV1 after fenoterol was 0.64 +/- 0.39 l (85% of total improvement) and after aminophylline 0.11 +/- 0.13 l (15% of total improvement). The improvement after aminophylline was statistically significant (p less than 0.01), though quantitatively small. Thirteen patients improved after aminophylline by less than 0.15 l, and in only five was the improvement 0.2-0.4 l. There was no significant change in heart rate and subjective tremor score with treatment, although observed tremor (0 = absent, 4 = maximum) increased from 0.4 +/- 0.6 to 1.3 +/- 1.0 after all treatment. For the majority of patients presenting with acute severe asthma, it is likely that high doses of nebulized beta-2 agonist alone will produce near maximal bronchodilation in the short term.