Sleep disorders pervade all levels of our society, affecting people of all ages, races, and socioeconomic levels. Up to 70 million Americans are estimated to have chronic disorders of sleep and wakefulness. Obstructive sleep apnea is the second most common sleep disorder after insomnia, affecting approximately 20 million Americans. Since the prevalence of sleep apnea increases with age, the graying of America over the next decade could dramatically escalate the cost of diagnosing and treating this disorder by the year 2010, according to a 2006 report by the Institute of Medicine. ENToday spoke with experts who treat obstructive sleep apnea about the latest advances in management and potential new approaches in the future.
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January 2007Sleep Testing
According to Peter Catalano, MD, who is Chairman of the Department of Otolaryngology at the Lahey Clinic in Burlington, Mass., and Associate Professor of Otolaryngology at Boston University, testing is going to become an area of active investigation. The polysomnogram (PSG) is the most widely used test for the degree of sleep apnea and other sleep disturbances, but this test has several limitations. Mainly, it lacks test-to-test reproducibility and it does not provide enough information to manage patients appropriately. The reliability of PSG depends on the experience and expertise of the technician, which is another variable, he added. Also, patients may be tested at more than one sleep laboratory, which further compromises reproducibility.
The test itself is uncomfortable and adversely affects sleep quality. Patients are vulnerable when they undergo PSG testing, because the test is done at night and sleeping is usually a private experience. Patients are usually awakened if they have apnea and a mask is strapped to their faces and they are told to go back to sleep. But they really have trouble going back to sleep and are frightened to move with equipment strapped to their faces, Dr. Catalano said.
Without question, PSG is a very fickle test that doesn’t always capture the true metrics. PSG does not identify sites of obstruction or which site is most critical, Dr. Catalano continued.
Site(s) of Obstruction
Three potential sites can be involved in obstructive sleep apnea: the nasal, palatal, and oropharyngeal sites. Apnea always involves the oropharyngeal site, but can also involve either the nasal or palatal sites-or all three sites. There may be a domino effect, Dr. Catalano explained, where obstructions in the first two sites affect the third site; or all three sites could be dominant in a given patient with obstructive sleep apnea.