High-dose inhaled versus intravenous salbutamol combined with theophylline in severe acute asthma. Swedish Society of Chest Medicine

Abstract

In a multicentre parallel group study we studied 176 adult patients (53% men) with severe acute asthma (peak expiratory flow (PEF), 15-50% of predicted values). The effect of two doses of inhaled salbutamol (0.15 mg.kg-1 x 2; 30 min apart) (n = 87) was compared with that of one dose of salbutamol given intravenously (5 micrograms.kg-1) (n = 89). There was a significantly larger increase in peak expiratory flow after the first inhaled dose in the group that received inhalation treatment than in the i.v. treated group (69 vs 41 l.min-1, p less than 0.05), but there was no difference in systemic side-effects between the groups. After the second inhaled dose there was a further increase in PEF, but also in systemic side-effects. These treatments were also compared in a cross-over study on 18 of the patients who returned with a second attack of severe acute asthma. The cross-over evaluation produced similar results, with a significantly larger increase in PEF after the first inhaled dose than after the i.v. treatment. Fifteen of the 18 patients found the inhalations more effective than the i.v. treatment. Theophylline (3-6 mg.kg-1) was infused i.v. 60 min after the start of salbutamol treatment, and a significant increase in PEF was observed in both groups. A correlation between the increase in PEF and the increase in plasma theophylline concentration was only found in the group that had received i.v. salbutamol.(ABSTRACT TRUNCATED AT 250 WORDS)