The effect of body position on sleep apnea in children younger than 3 years.

OBJECTIVE To determine the association between body position and obstructive events during sleep as determined by polysomnography (PSG) in very young children (age, < or = 3 years) with obstructive sleep apnea syndrome. DESIGN Retrospective chart review. SUBJECTS Children aged 3 years and younger who underwent PSG to evaluate obstructive sleep apnea and subsequently underwent adenotonsillectomy between December 1, 2000, and November 30, 2003, were included in the study. The PSGs were analyzed for data on the respiratory disturbance index (RDI), time spent in each body position, number of apneic events in each position, oxygen saturation, and time spent in each stage of sleep. The results determined the statistical significance of these parameters. RESULTS Sixty patients satisfied the criteria for inclusion in the study. The mean supine sleep RDI was 8.5 compared with 4.9 for the mean nonsupine sleep RDI. The mean RDI increased from 5.6 to 8.5 when more than 50% of the time was spent in supine sleep. There was a further increase to 10.5 when supine sleep increased to 75% of the total sleep time. The mean RDI in rapid eye movement sleep was 20.5 compared with 5.3 in non-rapid eye movement sleep. The mean +/- SD supine sleep RDI was 18.5 +/- 5.1, and the mean nonsupine RDI was 7.2 +/- 1.9, which was statistically significant (P = .02). CONCLUSIONS There is an increase in the RDI with increased time spent in supine sleep in very young children with obstructive sleep apnea. Inadequate time spent in that position may lead to an underestimation of the severity of obstructive sleep apnea. A combination of reduced rapid eye movement sleep and increased nonsupine sleep may invalidate the findings of PSG in these children.