Differentiating first episode of viral wheezing by assessing response to salbutamol nebulization in children 6 months to 2 years of age admitted as bronchiolitis-a prospective cohort study.

Abstract

Some infants diagnosed as bronchiolitis might actually be having their first episode of viral wheeze. Although wheezing is common to both conditions, their treatment approaches differ. The objectives of this study were to estimate the proportion of infants aged 6 months to 2 years with episodic viral wheeze (EVW) among those admitted as bronchiolitis, to determine the factors predicting salbutamol response, and to compare the short-term outcomes between them. This prospective observational study included infants admitted with bronchiolitis. Assuming that one fourth of them might be having EVW, with 5% alpha error and 80% power, the sample size was estimated to be 136, including an attrition of 10%. After obtaining parental consent, 2 doses of nebulized salbutamol were administered to assess treatment response. Baseline demographics, atopy status, and respiratory swab results were collected and analysed. The proportion of infants responding to salbutamol, the factors influencing response and the outcomes, were studied. Among the 137 participants studied, salbutamol response was observed in 50 (36.5%) and were designated as EVW. Family h/o atopy was seen in 25 (50%) participants in the EVW group compared to 13 (14.9%) in the bronchiolitis group (P = .0001). Shorter hospital stay (P = .018), oxygen (P = .016) and heated, humidified, high flow nasal cannula requirement (P = .03) was seen in EVW compared to the bronchiolitis group. To conclude, about one in three infants admitted as bronchiolitis presenting predominantly with wheeze, show a bronchodilator response. In them, a better treatment outcome is seen when managed as EVW.