RESUMO
BACKGROUND: Although international guidelines generally recommend the back to back use of short-acting ß-agonizts (SABA) within a short time in the management of acute wheezing in children with asthma, there is still uncertainty in the evidence of short term outcome. Thus, this study aimed to investigate the efficacy of back to back and single use of inhaled SABA by lung function testing. METHODS: This was a prospective, double-blinded, placebo controlled study conducted in children ≥6 years of age with a history of asthma. Children who presented with an acute asthma exacerbation (AAE) with a forced expiratory volume in 1 s (FEV1) between 40% to 60% were enrolled in the study if they had a first dose to SABA response of FEV1 ≥ 12%. All children were then randomly assigned either to receive two additional doses of inhaled SABA (300 µg per dose) or placebo. Spirometric analysis included forced vital capacity (FVC), FEV1, FEV1/FVC, PEF, and FEF25-75 at baseline, 15, 30, and 45 min for each group. Oxygen saturation and heart rate were monitored during the study period. RESULTS: A total of 93 patients (inhaled SABA group; n = 48 vs. placebo group; n = 45) out of 110 enrolled patients completed the study. Baseline demographic characteristics of patients include age, gender, age of diagnosis, parental asthma, history of allergic rhinitis and atopic dermatitis, current asthma treatment, IgE and skin prick test were similar among groups. (p > .05) When lung function parameters were compared at each time interval during the study period, there were no statistical significance found in FVC, FEV1, FEV1/FVC, PEF and forced expiratory flow between 25% and 75% (FEF25-75) among groups. (p > .05) There were also no differences between groups for changes in heart rate and oxygen saturation. (p > .05) CONCLUSION: A single dose of inhaled SABA provides similar short term bronchodilator effect as back to back administration of inhaled SABA in children with AAE who showed an initial response to SABA of FEV1 ≥ 12%.
