Continuous positive airway pressure acutely increases exercise duration in children with severe therapy-resistant asthma: a randomized crossover trial.

Abstract

Lower exercise tolerance is an important component of asthma and the possible effects of non-invasive ventilation on exercise capacity in individuals with severe therapy-resistant asthma (STRA) are unknown. This study aimed to evaluate the immediate effect of continuous positive airway pressure (CPAP) on exercise tolerance in children with STRA. We performed a controlled, randomized, crossover clinical trial including subjects aged 6 to 18years old diagnosed with STRA. Clinical, anthropometric and lung function data were collected. The participants in the intervention group (IG) used CPAP (PEEP 10cmH2O and FiO2 0.21) for a period of 40min. Subjects in the control group (CG) used CPAP with minimum PEEP at 1 cmH20 also for 40min. Afterwards, subjects from both groups underwent cardiopulmonary exercise testing (CPET). After a 15-day washout period, on a subsequent visit, subjects participated in the opposite group to the initial one. Thirteen subjects with a mean age of 12.30 ± 1.7years were included. The variables of peak expiratory flow (PEF) and forced expiratory volume in the first second (FEV1) before using CPAP and after performing CPET did not show significant differences. Regarding CPET results, there was no significant difference (P = 0.59) between groups at peak exercise for oxygen consumption-VO2 (CG: 33.4 ± 6.3 and IG: 34.5 ± 5.9, mLkg-1min-1). However, the IG (12.4 ± 2.1) presented a total test time (min) significantly (P = 0.01) longer than the CG (11.5 ± 1.3). The results suggest that the use of CPAP before physical exercise increases exercise duration in children and adolescents with STRA.