Diagnosing Obstructive Sleep Apnea

Using a sleep lab to diagnose sleep apnea
Using a sleep lab to diagnose sleep apnea

An evaluation of the head and neck through an office visit with an otolaryngologist can be a great start for determining if you or a loved one has obstructive sleep apnea. A standard visit with a full medical and sleep history, as well as an in-depth physical examination of the airway will determine any signs of nasal or throat/tongue obstruction and narrowing. If a concern arises, our sleep team will request and assist with facilitating a sleep study at the Millennium Sleep Lab centre.

The primary definitive method of diagnosing whether you have sleep apnea is through an overnight sleep study or polysomnography (PSG). This exam can be done in a sleep lab where you arrive at night (weeknights and weekends are usually available) and you sleep in a room similar to a hotel room with monitors. These monitors measure muscle movements, sleep stages, snoring, sleep apnea, and oxygen levels. An overnight PSG is considered the gold standard for diagnosing sleep apnea.

Home sleep studies are also performed now and are often required for initial screening by insurance companies. Home studies are generally easier to complete and are performed in the comfort of your own bed. They are either picked up or mailed to you; once the examination is complete, you can return the device via a pre-stamped box. Home studies have been shown to be a valid method of diagnosing sleep apnea, but are considered slightly less sensitive than a full sleep study. If a home sleep study is negative and your examination and history point to a high likelihood of OSA, a full sleep study may be ordered afterward.

Diagnostic Tools Used by Otolaryngologists to Determine OSA

Otolaryngologists specializing in sleep apnea treatment often perform diagnostic exams to better evaluate your airway:

Fiberoptic Nasolaryngoscopy – this diagnostic tool is a standard part of the initial office visit and is an office based scope exam. Nasalaryngoscopy is performed with a mild topical anesthesia and generally takes less than five minutes to perform. After a short acting topical numbing spray is given through the nose, a small fiberoptic camera is placed to follow the passage of air from the nose into the throat. The nose is evaluated for nasal obstruction, a deviated nasal septum, nasal polyps, sinus disease, and allergies that can cause significant nasal airway narrowing. The palate and throat are examined next. Any signs of abnormal tissue or enlargement of the tonsils or tongue are visualized and the aperture of the airway is recorded. The voice box and entryway into the windpipe (trachea) are also observed while masses and lesions of the nose and throat are carefully ruled out.

Drug Induced Sleep Endoscopy (DISE) – this diagnostic tool is a nasolaryngoscopy performed under sedation to examine the airway while the patient is falling asleep. The patient is brought into a procedure room or operating room and given an intravenous line. Much like a colonoscopy or EGD, medication is given to allow the patient to fall asleep while still breathing on their own. The medication is titrated to the point where the patient is snoring and mimicking their sleep apnea episodes and the procedure generally takes about 10 minutes to complete. This exam, compared to the awake office-based exam, is conducted to better understand the areas of collapse that are occurring, which are causing snoring and episodes related to sleep apnea. DISE is an extremely useful tool to more accurately ascertain the anatomic reasons behind sleep apnea, and to allow for more targeted therapy if surgery is decided upon.