Lung Disorders Special Report
Home Monitoring for Sleep Apnea
Sleep apnea affects an estimated 19 million. Getting diagnosed usually means spending a night in a sleep lab, but more convenient, less expensive home tests have been gaining credibility among sleep specialists. Recently, portable monitoring devices that can be used in the home were recommended by the American Academy of Sleep Medicine (AASM) to test for sleep apnea in some patients. Here's what you need to know.
Sleep apnea occurs when tissue in the back of the throat collapses and blocks the upper airway during sleep. This deprives the body of oxygen, until the sleeper gasps and briefly wakes up, thus opening the airway. Some patients awaken hundreds of times a night, causing daytime exhaustion. For that reason, they are seven times more prone to car accidents. People who have sleep apnea are also at increased risk for hypertension, heart attack, stroke, and diabetes. Not all people who snore have sleep apnea, but if you think you (or your spouse) may have the condition, get diagnosed right away.
Standard sleep apnea diagnosis. It's standard practice for patients who may have sleep apnea to visit a sleep laboratory for a night of tests, referred to as polysomnography. Most facilities have motel-like bedrooms with normal beds; some have televisions and adjoining bathrooms. Before you go to sleep, technicians attach electrodes to your head, chin, chest, and legs. These electrodes monitor brain activity, body position, eye movement, and heart rate, allowing technicians to determine the duration of your sleep and how often you wake up. Sensors near your nose and mouth measure airflow, and bands fitted to your chest and abdomen monitor breathing movements. A finger-clip measures blood oxygen saturation.
After the polysomnography, a report is sent to your physician, who will discuss it with you at a follow-up visit. One important result is your apnea-hypopnea index: The number of hours that you slept is divided into the number of airflow interruptions (apneas) and airflow reductions (hypopneas) that occurred during sleep. More than 5 apneas and/or hypopneas per hour indicate sleep apnea.
An alternative sleep apnea diagnostic test. Most insurance carriers cover lab polysomnography (about $1,500), but waiting lists can be long, and a sleep center may not be in your area. But now there are other options.
Last December, after reviewing 37 studies on portable monitoring for sleep apnea, the AASM recommended home testing with portable monitors for patients ages 18-65 who have clear symptoms of sleep apnea and who don't have other sleep disorders or significant medical conditions, such as heart failure or pulmonary disease.
Most home testing devices for sleep apnea are small and lightweight. You should use a device -- or a combination of devices -- that measures (at minimum) airflow, respiratory effort, and blood oxygen levels. The raw data must be manually scored by a sleep technologist and then evaluated by a sleep specialist (instead of automatically interpreted by a machine).
If your home test is positive, there is some debate about your next step. Some experts argue that patients should go to a sleep lab for initial therapy, while others advise starting treatment right away in the home.
Who Needs Testing? Not all people who snore have sleep apnea, but snorers with these symptoms or several of these risk factors should get tested.
Symptoms:
- Snoring that can be heard through the bedroom door
- Choking/snorting during sleep
Risk factors:
- Obesity or being overweight
- Hypertension
- Daytime sleepiness
- Regular drinking
- Male gender
- Being over age 40
Posted in Lung Disorders on April 2, 2009
