Dose of nebulized ipratropium bromide in acute severe asthma

The aim of the study was to determine the maximum effective dose of nebulized ipratropium bromide, 0.5 or 1.0 mg, in the treatment of acute severe attacks of asthma. Thirty-two patients (ten males, 19-53 years) who were admitted with acute severe asthma were, in a double-blind trial, randomized to receive either 0.5 or 1.0 mg of isotonic, preservative-free ipratropium bromide nebulized in saline. Ear oxygen saturation, peak flow and heart rate were measured on admission and regularly following nebulization. Two hours after nebulization of the ipratropium, terbutaline (5 mg) was administered by nebulizer and further measurements taken 30 min later. Twenty-six patients completed the study, 13 in each group. Peak expiratory flow (PEF) increased by 51% [1211 min-1 increasing to 1831 min-1 (mean)] in the 0.5-mg ipratropium group, and by 37% (1551 min-1 to 2071 min-1) in the 1.0-mg group. There were no significant differences in heart rate or ear oxygen saturation changes between the groups. Nebulized terbutaline led to a small further rise in peak flow in both groups (341 min-1 in the 0.5-mg group; 411 min-1 in the 1.0-mg group). No side-effects were noticed in either group. We conclude that 0.5 mg of nebulized ipratropium is as effective as 1.0 mg in the treatment of acute severe asthma.