Obstructive Sleep Apnoea (OSA) is a sleep disorder characterised by abnormal breathing during sleep. Patients with OSA have severe airway obstruction during sleep which results in significant sleep disturbance, repeated cycles of low oxygenation and impairment of daytime function.
Individuals with OSA have a narrower and more collapsible upper airway causing repeated upper airway obstruction during sleep. When breathing stops, the level of oxygen in the bloodstream falls. The brain senses this decrease in oxygen and rouses the person from sleep. With awakening, the muscles at the back of the throat become more active and hold the airway open so that breathing can resume.
The repeated awakenings make it hard to get a good night's sleep, resulting in poor sleep quality and sleep deprivation. The upper airway obstruction leads to decreased oxygen supply to the brain, heart and other organs and puts tremendous stress on the heart and body, leading to medical consequences in the long run.
Someone with OSA may present with loud and habitual snoring, excessive daytime sleepiness, feeling unrefreshed despite adequate sleep hours, falling asleep while driving, depression, irritation, decreased libido and morning headaches. Their sleep partners may also notice gasping and choking episodes during sleep. As the lack of sleep is very stressful, affected individuals may become irritable, undergo changes in personality, or have difficulty with memory.
Untreated OSA may lead to high blood pressure. There are also higher incidences of ischaemic heart disease, irregular heart rhythm and strokes in individuals with OSA. When OSA is severe, heart failure may occur. Untreated OSA is also associated with increased risk of sudden death and premature death.
Any condition that contributes to the narrowing at the back of the throat such as enlarged tonsils or adenoids favour the development of OSA.
Large tonsils are the most common cause of sleep apnoea in infants. They can also be the occasional cause of problems in adults although nasal and soft palate problems are the more common causes of adult OSA.
Other factors which may influence the snoring condition and the development of OSA are obesity, ageing and associated loss of general muscle tone, throat congestion due to reflux of stomach acid (heartburn); and the effects of alcohol, sedatives and smoking.
In obesity, excessive fat accumulation in the upper airway may amplify an existing anatomic narrowing of the upper airway that was causing minimal obstruction previously.
OSA is also more common among males and in individuals with a genetic predisposition leading to facial and jaw abnormalities.
To diagnose OSA, a thorough examination of the nose, mouth, throat and neck is performed. In someone with significant snoring, sleep apnoea needs to be ruled out. The evaluation usually involves an overnight monitoring of sleep, called a sleep study or polysomnogram.
Effective treatment is available for almost all patients. Treatment of both snoring and OSA requires a multidisciplinary approach.
A medical device called Continuous Positive Airway Pressure (CPAP) may be recommended for patients with moderate to severe OSA. This device delivers room air to the nose and back of the throat at a slightly elevated pressure to prevent the airway from collapsing during sleep. CPAP is safe, generally well-tolerated and highly effective. This device must be worn nightly and long-term CPAP compliance is essential for its effectiveness.
Dental appliances that reposition the lower jaw and tongue have been helpful in some patients with mild OSA and snoring. Dental appliances have to be worn every night. Dental and lower jaw joint side effects may prevent compliance.
Surgery may be recommended for treatment of OSA for some individuals. Surgery is individualised and may range from procedures designed to open the nose and enlarge the back of the throat. Medications are ineffective in treating OSA.
Some useful suggestions for snorers: