Young children with obstructive sleep apnoea who sleep on their backs (the supine position) appear to have more respiratory problems, as measured by increases in the respiratory disturbance index (RDI). As such, the severity of the apnoea could be underestimated in children who do not spend much time in this position. Obstructive sleep apnoea syndrome is a condition in which airways become blocked periodically during sleep and breathing stops for brief periods. Symptoms improve in adults with this condition when they avoid the supine position Researchers from the University of Texas Health Science Center at Houston, USA, analysed data from 60 children with the condition who underwent polysomnography, a test used to diagnose obstructive sleep apnoea, as part of their work-up. The RDI increased as the amount of time in the supine position rose. When more than half the sleeping time was spent in the supine position, the average RDI rose from 5.6 to 8.5. When this position accounted for 75 percent of sleep time, the RDI increased further to 10.5. The average RDI was also much higher during rapid eye movement (REM), sleep than in other sleep stages: 20.5 versus 5.6. The most significant finding in the study was that the RDI in the supine position was greater than in all other positions combined. A combination of reduced rapid eye movement sleep and increased non-supine sleep may invalidate the findings of polysomnography in very young children with obstructive sleep apnoea.
Archives of Otolaryngology - Head and Neck Surgery,
November 2005