Central apnoeas have significant effects on blood pressure and heart rate in children

Brief central apnoeas (CAs) during sleep are common in children and are not usually considered clinically significant unless associated with oxygen desaturation. CAs can occur spontaneously or following a movement or sigh. The aim of this study was to investigate acute cardiovascular changes associated with CAs in children. Beat-by-beat mean arterial pressure (MAP) and heart rate (HR) were analysed across CAs, and spontaneous and movement-induced events were compared using two-way analysis of variance with post hoc analyses. Fifty-three children (28 male/25 female) aged 7-12 years referred for investigation of sleep-disordered breathing (SDB) and 21 age-matched healthy controls (8 male/13 female) were studied. Children underwent routine clinical polysomnography with continuous blood pressure (BP) recordings. Movement-induced, but not spontaneous, CAs were more frequent in children with mild or moderate/severe obstructive sleep apnoea (OSA) compared with healthy controls (P < 0.05 for both). Movement-induced CAs were associated with significantly larger MAP and HR changes across the event compared with spontaneous CAs. The percentage changes in MAP and HR between late-event and post-event were significantly greater for movement-induced compared with spontaneous CAs (MAP 20.6 +/- 2.3 versus 12.2 +/- 1.8%, P < 0.01; HR 28.2 +/- 2.6 versus 14.7 +/- 2.5%, P < 0.001). This study demonstrates that movement-induced CAs are more common in children with OSA, and are associated with significantly greater changes in HR and BP compared with spontaneous CAs. These data suggest that movement-induced CAs should be considered when assessing the cardiovascular impact of SDB.