RESUMO
OBJECTIVE: To determine whether noninvasive therapy using a helium-oxygen mixture reduces the use of positive-pressure ventilation in the treatment of respiratory failure caused by severe bronchiolitis. STUDY DESIGN: This was a multicenter, randomized, double-blind, placebo-controlled trial that recruited infants in 4 pediatric intensive care units (PICUs). A total of 39 nonintubated infants with severe bronchiolitis caused by respiratory syncytial virus (RSV) were randomly assigned within 8 hours of PICU admission to receive a helium-oxygen mixture (helium group) or an air-oxygen mixture (control group) through an inflatable head hood. The primary study outcome was the requirement for positive pressure mechanical ventilation. Results were compared using Fisher's exact test. RESULTS: No differences were noted between the control and helium groups with respect to age (1.0 vs 1.1 months), prematurity, or family history of asthma or smoking. Positive pressure ventilation was judged necessary for 4 of the 21 (19.0%) infants in the control group and in 4 of the 18 (22.2%) in the helium group (relative risk = 1.17; 95% confidence interval = 0.34 to 4.01). CONCLUSIONS: This study did not detect any differences between the patients in the helium group and the control group with respect to the rate of positive-pressure ventilation.