Children aged three and younger who have a sleeping disorder known as sleep apnea show more respiratory disturbance when they sleep on their backs, according to a study in the November issue of Archives of Otolaryngology - Head & Neck Surgery.
Obstructive sleep apnea syndrome (OSAS) is a serious medical problem affecting an estimated half a million children per year in the United States, according to background information in the article. Pediatric OSAS is most commonly caused by enlarged tonsils and adenoids. It is characterized by episodes of partial or complete upper airway obstruction that occur during sleep, including snoring, cyanosis (a bluish color of the skin and mucous membranes), and poor quality of sleep. Symptoms during the day can include mouth breathing, behavior problems, hyperactivity, and excessive daytime sleepiness. While research among adults has shown a significant decrease in OSAS episodes when patients avoid sleeping on their backs (the supine position), the issue of sleep position is not as well understood among children with OSAS.
Kevin D. Pereira, M.D., and colleagues at the University of Texas Health Science Center at Houston conducted a retrospective chart review to evaluate the association between body position and OSAS events during sleep in children aged three and younger. The study included 60 children who underwent polysomnography (PSG, the continuous recording of physiologic variables during sleep) to evaluate OSAS, and later had surgery to remove their tonsils and adenoid tissue, between December 1, 2000, and November 30, 2003. The PSGs were analyzed for data on the respiratory disturbance index (RDI, an index measuring respiratory events that disturb sleep), time spent in each body position during sleep, the number of apneic events in each position, oxygen saturation, and time spent in each stage of sleep.
The authors found there was an increase in the RDI with increased time spent in supine sleep. "The mean RDI increased from 5.6 to 8.5 when more than 50 percent of the time was spent in supine sleep," they write. "There was a further increase to 10.5 when supine sleep increased to 75 percent of the total sleep time." The most significant finding was that the RDI in the supine position was greater than in all other positions combined.
"The results of our study indicate that supine sleep does correlate with an increase in RDI as well as with OSAS in pediatric patients younger than three years," the authors write. "This finding is in contrast to previous studies that have demonstrated no correlation between sleep position and OSAS in children."
The authors urge clinicians who use PSG to diagnose and manage sleep disorders in children to take into consideration the variables that may affect the validity of the results. "Lack of adequate supine sleep may be an important factor in symptomatic children with normal sleep study results."