A machine that delivers air through a nasal mask worn during sleep can reduce daytime sleepiness and other symptoms associated with sleep apnea, but apnea patients are not always happy with the treatment, according to two new reviews of recent studies.
In apnea patients, the airway in the nose and throat periodically narrows or closes off during sleep, stopping breathing for seconds at a time. People with apnea usually snore and feel sleepy and less alert in the daytime. Some studies suggest apnea can contribute to high blood pressure, heart disease and stroke and may be a factor in traffic accidents.
The reviews appear in the current issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.
Air mask treatment, also known as continuous positive airway pressure or CPAP, is the main treatment for apnea. In their review, Tammie Giles of the Queen Elizabeth Hospital in Adelaide, Australia, and colleagues concluded that CPAP can significantly improve apnea symptoms compared to no treatment or treatment with less invasive methods, such as oral spacers or tongue depressors worn in the mouth to open up the airway.
Patients using CPAP reported feeling less sleepy and more physically and mentally healthy than those not using CPAP. They also had 17 fewer apnea episodes per hour of sleep, the researchers found. CPAP patients in several of the studies also lowered their blood pressure after starting the treatment.
“The overall results demonstrate that in people with moderate to severe sleep apnea CPAP can improve measures of sleepiness, quality of life and mood and associated daytime sleepiness,” Giles said.
In a second review, Jerome Lim and colleagues found that spacers and other oral appliances can improve apnea symptoms compared to no treatment, but they do not work as well as CPAP for most patients.
Lim and colleagues say their findings suggest oral appliances should not be used as “first choice therapy” for people with severe apnea.
However, “it would appear to be appropriate to recommend oral appliance therapy to patients with mild symptomatic obstructive sleep apnea and those patients who are unwilling or unable to tolerate CPAP therapy,” Lim says.