Altered cardio-respiratory response to spontaneous cortical arousals in children with upper airway obstruction

Abstract

<h4>Objective</h4>Upper airway obstruction (UAO) during childhood is associated with cardiovascular morbidity. The aim of this study was to investigate the cardio-respiratory response to cortical arousal during sleep in children with UAO.<h4>Methods</h4>Standard paediatric overnight polysomnography (PSG) was conducted in 40 children with UAO (25M, 7.5±2.7yrs) prior to and 6 months following adenotonsillectomy. For comparison a control group of 40 normal, sex and age matched children (21M, 7.5±2.6yrs) underwent two PSGs without intervention at the same time points.<h4>Results</h4>Heart rate and respiratory rate were measured during spontaneous and respiratory arousals in stage 2 and REM sleep 15s prior to and 15s immediately following cortical arousal onset. Cortical arousal was associated with a significant increase in heart and respiratory rate in both groups of children. UAO children, however, showed a significantly higher heart rate response in stage 2 sleep (-17.5±6.0 vs. -14.4±4.8%; p<0.05), a lower pre-arousal baseline respiratory rate (stage 2: 17.1±1.4 vs. 18.2±1.7 BPM; p<0.01) and a prolonged increase in respiratory rate compared to control children. Cardiac and respiratory arousal responses were not significantly different from controls following adenotonsillectomy in the UAO children.<h4>Conclusions</h4>UAO in children is associated with an altered cardiorespiratory response to spontaneous arousal from sleep, which may indicate early signs of autonomic dysfunction. Surgical treatment of UAO appears to reverse these outcomes.