Randomised pragmatic comparison of UK and US treatment of acute asthma presenting to hospital.

BACKGROUND Systemic corticosteroids and inhaled beta(2) agonists are accepted first line treatments for acute severe asthma, but there is no consensus on their optimum dosage and frequency of administration. American regimens include higher initial dosages of beta(2) agonists and corticosteroids than UK regimens. METHODS In a prospective, pragmatic, randomised, parallel group study, 170 patients of mean (SD) age 37 (12) years with acute asthma (peak expiratory flow (PEF) 212 (80) l/min) presenting to hospital received treatment with either high dose prednisolone and continuous nebulised salbutamol as recommended in the US or lower dose prednisolone and bolus nebulised salbutamol as recommended in the UK by the BTS. RESULTS Outcome measures were: deltaPEF at 1 hour (BTS 89 l/min, US 106 l/min, p=0.2, CI -8 to 41) and at 2 hours (BTS 49 l/min, US 101 l/min, p<0.0001, CI 28 to 77); time to discharge if admitted (BTS 4 days, US 4 days); rates of achieving discharge PEF (>60%) at 2 hours (BTS 64%, US 78%, p=0.04); time to regain control of asthma as measured by PEF >/=80% best with </=20% variability (BTS 3 days, US 4 days, p=0.6); PEF at 24 hours in patients admitted (BTS 293 l/min, US 288 l/min, p=0.8); and control of asthma in the subsequent month (no significant differences). CONCLUSIONS Treatment with higher doses of continuous nebulised salbutamol leads to a greater immediate improvement in PEF but the degree of recovery at 24 hours and speed of recovery thereafter is achieved as effectively with lower corticosteroid doses as recommended in the British guidelines.