During sleep, the muscles of the body relax. Sometimes the throat muscles realax so much that the upper airway in the throat collapses completely, preventing air reaching the lungs. This is sleep apnea. As a result the body is starved of oxygen, and wakes up in order to breathe (this is often accompanied by a loud snort). Often this pattern of relaxation, airway collapse and waking repeats as a cycle throughtout the night, with varying frequency. If the pattern repeats more than about 10 times per hour, there is a strong likelihood of medical problems arising, in particular high blood pressure. Chronic sleep apnea typically results in various symptoms, which may include:
- short temper and irritability
- decreased sex drive
- loud snoring, accompanied by gasps
- anxiety or depression
- excessive daytime sleepiness
Many people who exhibit some or all of the above symptoms may not in fact have sleep apnea. A sleep study performed at a dedicated sleep clinic is the most reliable means of diagnosis, using a procedure known as polysomnography.
Sleep Centre Polysomnography
During the sleep study, the patient spends the night at the sleep clinic and is connected to various measuring devices. They record the following:
- breathing and heart rate
- amount of oxygen in the blood
- how much air moves in and out of the lungs while asleep
A video camera records body movement during the night.
Overnight polysomnography remains the best way of diagnosing sleep apnea. However, it is labour-intensive and expensive. Portable devices are being developed so that patients can be monitored in their own home. Some of these devices are not able to measure the full range of factors that typically would be recorded in the sleep clinic.
Treatment of Sleep Apnea
Once sleep apnea has been diagnosed, there are few options for effective treatment. In mild cases the incidence of sleep apnea can be reduced by weight loss. In some cases surgery can be helpful, such as uvulopalatopharyngoplasty (UPPP), which is a procedure that removes excess tissue in the throat to make the airway wider. This sometimes can allow air to move through the throat more easily when breathing, reducing the severity of obstructive sleep apnea. Generally, however, the success rate of surgery is less than 50%.
The most effective treatment is using a CPAP machine, as described here: Using a CPAP Machine to Control Snoring and Sleep Apnea . This procedure does have the disadvantage of the patient having to wear a mask every night, either a full-face or nose mask . There is no infallible cure for sleep apnea, but using a CPAP machine enables it to be successfully managed.
Sources:
www.cpap.co.uk, "CPAP - Sleep Apnea - Snoring," (accessed June 7, 2010)
Patil SP, Schneider H, Schwartz AR, Smith PL. Adult obstructive sleep apnea: pathophysiology and diagnosis. Chest. 2007 Jul;132(1):325-37.
Trevor Lewis - Trevor Lewis has been working in the IT industry for the last thirty years. He also has a long-standing interest in astronomy and space ...
