Background: The role of intravenous aminophylline in acute asthma is unclear despite meta-analysis of many studies comparing aminophylline with other bronchodilator therapies.
Aims: The aim of this study is to determine whether continuous aminophylline infusion confers any benefit in acute severe asthmatics treated with intravenous steroids and inhaled bronchodilators.
Methods: The study was randomised, double-blind and placebo-controlled. All patients received nebulised salbutamol (1 mL of 0.5%) and ipratropium bromide (1 mL of 0.025%) with glycol diluent (1 mL) at 0, two, four, six, eight and 12 hours, and six-hourly thereafter. In addition all patients were given intravenous hydrocortisone 250 mg six-hourly and oxygen to maintain normoxia. Aminophylline infusions were adjusted to maintain therapeutic levels. Peak expiratory flow rate (PEFR) was measured before and after nebulised bronchodilator on a two-hourly basis in the Emergency Department (ED) and six-hourly on the inpatient wards.
Results: Thirty-one patients were clinically sufficiently improved within 12 hours to be discharged home from the ED. The remaining 28 patients were admitted to the inpatient ward for a total trial duration of 48 hours. No significant difference was found between the placebo and treatment groups for measurements of PEFR, or for the duration of stay of the patients in hospital. The power of the study was 80% for a 25% to 33% difference at a 5% level of significance. Presentation values of PEFR and arterial blood gases did not predict which patients would require inpatient admission and which could be safely discharged home from the ED.