Apnea patients can safely skip the sleep lab
People whose symptoms make it highly likely they have obstructive sleep apnea (OSA) can safely start treatment without first obtaining a confirmatory diagnosis in a sleep laboratory.
So concludes a study in Vancouver, Canada, that found no difference in outcomes between OSA patients who had two nights of polysomnography (PSG) in a lab before starting continuous positive airway pressure (CPAP) therapy and those who were prescribed CPAP without PSG evidence.
The American Academy of Sleep Medicine and the American Thoracic Society recommend a two-night lab PSG study to confirm OSA, but because there are too few beds to meet the demand, the requirement can delay treatment for this potentially fatal condition. Like any inpatient procedure, it’s also expensive.
All 68 participants in the study showed symptoms that made it at least 90% likely they had OSA, including snoring, witnessed episodes of apnea, hypertension, and a thick neck. They were then randomly assigned to begin CPAP therapy with or without PSG. Both groups had similar median BMI (38) and median age (55 years).
After three months, the apnea-hypopnea index was similar in both groups. Sleepiness, quality of life, and residual sleep-disordered breathing were similar as well.
Only one patient who did not go to the sleep lab was misdiagnosed. The error was caught within two weeks, when he did not respond to CPAP. This led the researchers to recommend a two-week reassessment if patients placed directly on CPAP do not improve (Ann Intern Med. 2007; 146:157-166).