|
Obstructive sleep apnea is much more common in children than most people think. Older studies state it occurs in 2 percent to 4 percent of the pediatric population, but sleep experts realize the current pediatric obesity epidemic is ramping up the prevalence of OSA. They also know that pediatric OSA results in significant medical problems involving learning, behavior, development, growth, strain on the heart, and high blood pressure.
What they don't know yet is what level of OSA to treat with adenotonsillectomy surgery in young children. "It's more obvious for very severe cases," said Carole L. Marcus, MBBch, director of the Sleep Center at The Children's Hospital of Philadelphia. "But we also see many mild or intermediate studies. At what level do the benefits outweigh the risks of surgery?"
The Randomized Controlled Study of Adenotonsillectomy for Childhood Sleep Apnea (CHAT) aims to give sleep practitioners some guidance. The study, which is funded by National Heart, Lung, and Blood Institute, is the first randomized controlled study to evaluate the current standard of OSA treatment in children.
Six major academic centers are actively recruiting participants, and they have already reached half their recruitment goal. More than 200 children ages 5 to 9 with large tonsils and adenoids who have breathing problems during sleep have been randomized into two groups.
The early treatment group receives adenotonsillectomy surgery within one month after enrollment. The watchful waiting group is re-evaluated for surgery after a seven-month waiting period. As children in the latter group grow during the course of the study, their lymphoid tissue may shrink, and their airways may get bigger, which may help to alleviate OSA symptoms without surgery.
Children receive an overnight sleep study before enrollment to confirm an OSA diagnosis (obstructive apnea index > 1 or apnea hypopnea index > 2). Once they become study participants, researchers monitor their growth, blood pressure, learning, and behavior. Participants' families also receive educational materials about healthy sleep habits and nutrition. A second sleep study is conducted at the end of the seven months, and researchers compare the results to the participants' initial scores.
In addition to determining whether OSA symptoms improve after surgery, CHAT also will consider surgery's effects on subgroups by race and weight. For example, while the majority of young children with OSA usually show improvement after their tonsils and adenoids are removed, obese children may still have residual issues.
Non-obese children can experience residual OSA as well, especially those with craniofacial abnormalities, small jaws, and large palates. "Two things occur in OSA," Dr. Marcus said. "One is a narrow airway, such as in big tonsils and obesity. The other is some children have more floppy muscle tone." This helps to explain why children with large tonsils can be asymptomatic, whereas others with small tonsils can have severe OSA.
"OSA is very treatable, and if we have better ways of diagnosing, then maybe we will know better which children to treat," said Dr. Marcus, who is a principal investigator for CHAT.
Although adenotonsillectomy is one of the most common surgeries for children, it has potential complications. Non-surgical options include weight loss and continuous positive airway pressure, but adherence to these therapies can be difficult for pediatric patients. Researchers also are investigating future pharmacological targets.
Sharlene George, editor of ADVANCE, can be reached at sgeorge@advanceweb.com.
|