Acute Effects of Noninvasive Ventilation on Autonomic Modulation Following Exercise-Induced Bronchoprovocation in Asthmatic Children

Aims:To evaluate the autonomic modulation and clinical responses during testing of exercise-induced bronchoprovocation (EIB) and when applying non-invasive ventilation (NIV). Methods:A cross-sectional study that evaluated the heart rate variability at rest, during testing of EIB, in rest after 10 minutes of EIB, and during NIV with bilevel pressure with inspiratory positive airway pressure 12 cmH2O and expiratory positive airway pressure 8 cmH²O. Anthropometric evaluation was performed, examining inflammation and lung function. Clinical control was assessed by questionnaire (Asthma Control Questionnaire 6 [ACQ6]). Results: A cohort of 55 children aged 10.0±3.3 years were split in response to bronchial provocation test results into a responding group (RG) (n=39) or non-responding group (NRG) (n=16). There was a significant difference between the RG and NRG in clinical control as assessed by ACQ6 (RG=1.16 [0.33–2.0] partially controlled and NRG=0.58 [0.2–1.3] controlled). There was a significant difference in both the time domain and the frequency domain of the heart rate variability, indicating an inhibition of the parasympathetic nervous system during testing of EIB that did not return to baseline levels after 10 minutes and only started to return after the use of NIV in both groups, but the parasympathetic inhibition during the bronchial provocation test in the RG was higher than in the NRG. Conclusions:The RG presented with worse clinical control in addition to a less effective autonomic regulation. In both groups, NIV assisted in the return of autonomic activity basal levels after the bronchial provocation test.