Adult Obstructive Sleep Apnoea

Obstructive sleep apnoea is one of the most common sleep disorders. It is caused by a collapse in the upper airways causing oxygen desaturation in the body and disrupting sleep.

Sleep apnoea is characterized by repetitive pharyngeal collapse during sleep. The consequent interruption of the gaseous exchange causes a number of problems such as oxygen insufficiencies, hypercapnia and the disruption of sleep which are related to metabolic, cardiovascular and neurocognitive effects in affected individuals.

The pharyngeal collapse may lead to complete collapse of the upper airway which is referred to apnoea while partial collapse is referred to as hypopnoea. Obstructive sleep apnoea, according to a Wisconsin sleep cohort study in 1993, is defined as five apnoea or hypopnoeas per hour of sleep.

The diagnosis of sleep apnoea can be done by checking for symptoms such as snoring, choking sensation in your sleep, difficulty in falling asleep and maintaining sleep, daytime sleepiness, fatigue and tiredness and morning headaches.  A family history of sleep apnoea can also be checked to arrive at a diagnosis.

A definite diagnosis of sleep apnoea is only reached by a visit to the doctor for an overnight sleep study called a polysomnography. The study done in a laboratory will give the apnoea-hypopnoea index from evaluation of sleep and respiration. Another test is the electromyography of the anterior tibialis to evaluate limb movements. The polysomnograph is definitive although it is a cumbersome, expensive and time consuming.

The risk factors for obstructive sleep apnoea are often the pathogenic triggers and mechanisms causing the problem. This means that even treatment should be approached differently depending on the cause of the sleep apnoea. Even though CPAP therapy is recommended irrespective of the underlying causes, treatment tailored to address the cause of the problem will increase the chances of successful elimination of the problem. Other approaches include the use of sedatives to help dilate muscles of the upper airway, controlling obesity which affects the lung volume during sleep, mechanical problems and use of diuretics to treat the retention of fluids in the body and especially the legs. Other risk factors that must be put into perspective are age, gender, genetics, menopause, race and lifestyle factors such as smoking and alcoholism. Management of obstructive sleep apnoea can be done through CPAP therapy, nasal decongestants, heated humidification, uvulopalatopharyngoplasty and somnoplasty, tracheostomy and maxilla-mandibular advancement among many other treatment and management options.  

Early treatment and management of obstructive sleep apnoea will eliminate the consequences associated with the sleep disorder. Different studies indicate that sleep apnoea is responsible for vehicle accidents, hypertension, cardiovascular diseases such as myocardial infarction, stroke and congestive heart failure; increased cancer risk, and diabetes mellitus.

http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2813%2960734-5/fulltext

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