Obstructive sleep apnea (OSA) is a sleep-related breathing disorder that involves a decrease or complete halt in airflow despite an ongoing effort to breathe. It occurs when the muscles relax during sleep, causing soft tissue in the back of the throat to collapse and block the upper airway. This leads to partial reductions (hypopneas) and complete pauses(apneas) in breathing that last at least 10 seconds during sleep. Most pauses last between10 and 30 seconds, but some may persist for one minute or longer. This can lead to abrupt reductions in blood oxygen saturation, with oxygen levels falling as much as 40percent or more in severe cases.
The brain responds to the lack of oxygen by alerting the body, causing a brief arousal from sleep that restores normal breathing. This pattern can occur hundreds of times inone night. The result is a fragmented quality of sleep that often produces an excessive level of daytime sleepiness.
Most people with OSA snore loudly and frequently, with periods of silence when airflowis reduced or blocked. They then make choking, snorting or gasping sounds when theirairway reopens.
A common measurement of sleep apnea is the apnea-hypopnea index (AHI). This is an average that represents the combined number of apneas and hypopneas that occur per hour of sleep.
Involuntary sleepiness during activities that require little attention, such as watching TV or reading.
Involuntary sleepiness during activities that require some attention, such as meetings or presentations.
Involuntary sleepiness during activities that require more active attention, such as talking or driving.
Sleep apnea must first be diagnosed at a sleep center or lab during an overnight sleep study, or “polysomnogram.” The sleep study charts vital signs such as brain waves, heart beat and breathing.
CPAP is the standard treatment option for moderate to severe cases of OSA and a good option for mild sleep apnea. First introduced for the treatment of sleep apnea in1981, CPAP provides a steady stream of pressurized air to patients through a mask that they wear during sleep. This airflow keeps the airway open, preventing pauses inbreathing and restoring normal oxygen levels. Newer CPAP models are small, light and virtually silent. Patients can choose from numerous mask sizes and styles to achieve a good fit. Heated humidifiers that connect to CPAP units contribute to patient comfort.
An oral appliance is an effective treatment option for people with mild to moderateOSA who either prefer it to CPAP or are unable to successfully comply with CPAP therapy. Oral appliances look much like sports mouth guards, and they help maintain an open and unobstructed airway by repositioning or stabilizing the lower jaw, tongue, soft palate or uvula. Some are designed specifically for snoring, and others are intended to treat both snoring and sleep apnea. They should always be fitted by dentists who are trained in sleep medicine.
Surgery is a treatment option for OSA when noninvasive treatments such as CPAP or oral appliances have been unsuccessful. It is most effective when there is an obvious anatomic deformity that can be corrected to alleviate the breathing problem. Otherwise, surgical options most often address the problem by reducing or removing tissue from the soft palate, uvula, tonsils, adenoids or tongue. More complex surgery may be performed to adjust craniofacial bone structures. Surgical