Wearing a special mask to bed helps children with sleep apnea breathe and sleep better, but a small, six-month study at Johns Hopkins Children's Center and two other pediatric hospitals suggests children aren't always using them consistently enough to reap the maximum benefits.
The breathing masks, which deliver a gentle, steady flow of air called positive airway pressure (PAP) therapy, significantly improved breathing and oxygen levels when worn regularly, researchers report in the March issue of Pediatrics. Parents also reported that their children had improved daytime alertness at school. Sleep apnea is marked by loud snoring and disturbed sleep caused by interrupted breathing patterns.
"Despite improvements with even irregular use of the device, parents often say children are using PAP when the study shows they are not," says investigator Ann Halbower, M.D., pediatric pulmonologist at the Johns Hopkins Children's Center. "Obstructive sleep apnea can cause learning, memory and IQ problems. Additionally, it affects breathing and oxygen levels, and while PAP therapy helps the apnea, the maximum benefits come only over time and with consistent use."
For the study, researchers enrolled 29 children between 2 and 16 years of age and instructed them to use the PAP masks at home every night. The 29 children underwent a baseline sleep study at enrollment, and 20 of them returned for a follow-up sleep study after six months. In addition, investigators surveyed the parents of the 20 children who completed the study to get their account of usage, and also tallied recorded usage data built into the PAP devices.
Comparing baseline and follow-up measures, researchers found a nine-fold average decrease in children's apnea hypopnea index (AHI), which represents the number of interruptions in breathing per hour. Oxygen saturation improved by an average 12 percent.
"What this means is that with treatment, sleep apnea basically went from severe to mild or better," Halbower says.
It remains unclear how PAP therapy affects neurocognitive performance, even though parents reported improved alertness and dramatic reduction in the percentage of children who fell asleep during school at least once a week. Halbower cautions that these outcomes are based on subjective reports, and further studies are needed to document objectively the device's effect on neurocognitive function. There was no difference in reported academic performance, irritability or hyperactivity.
Comparing parents' reports and data obtained from the device's computerized meter, researchers found that parents tended to overestimate usage by approximately two hours. Even those who used the equipment every night only did so for an average of five hours a night, which is insufficient, given children's long sleep hours, Halbower says. In addition, 78 percent of parents told researchers that their children did not use the equipment every night.
The study did not address reasons for non-adherence to PAP therapy. Halbower says further studies are needed to examine reasons for non-adherence and to develop treatments for those children who cannot tolerate PAP.
Obstructive sleep apnea syndrome affects 2 percent of children in the United States. It occurs because of partial or complete obstruction of the airways during sleep due to anatomic and/or neuromotor factors. In children, the leading cause of sleep apnea is enlarged tonsils and adenoids, and the first line of treatment is surgical removal. If untreated, sleep apnea may lead to serious problems in later life, including hypertension, cardiovascular disease, diabetes and increased mortality.
The study's principal investigator is Carole Marcus, M.D., Children's Hospital of Philadelphia.
Co-investigators included Laura Sterni, M.D., assistant professor of pediatric pulmonology, and Janita Lutz, both of Johns Hopkins Children's Center; Gerald Rosen, M.D., and Pamela Stading, M.D., University of Minnesota School of Medicine; Sally Davidson Ward, M.D., and Daisy Bolduc, M.D., University of Southern California School of Medicine; and Nancy Gordon, of Gordon & Associates, consultant to ResMed Corp, a manufacturer of respiratory medical devices.