14. Management of obstructive sleep apnoea
In this series featuring information for patients and professionals taken from SIGN’s evidence-based guidelines, we reproduce the ‘information for discussion with patients and carers’ section from SIGN guideline number 73, on management of obstructive sleep apnoea/hypopnoea syndrome in adults.
What is sleep apnoea/hypopnoea syndrome?
People who suffer from obstructive sleep apnoea/hypopnoea syndrome (OSAHS) breathe shallowly or stop breathing for short periods while sleeping.This can happen many times during the night. It results in poor sleep leading to excessive sleepiness during the day. Because these events occur during sleep, a person suffering from OSAHS is often the last one to know what is happening.
In deep sleep the muscles of the throat relax. Normally this doesn’t cause any problems with breathing. In OSAHS, complete relaxation of the throat muscles causes blockage of the upper airway at the back of the tongue.Normal breathing then slows or stops completely. Such an episode is called an apnoea.
During an apnoea, people with OSAHS make constant efforts to breathe against their blocked airway until the blood oxygen level begins to fall. The brain then needs to arouse the person from deep relaxed sleep so that the muscle tone returns, the upper airway then opens and breathing begins again. Unfortunately, when a person with OSAHS falls back into deep sleep, the muscles relax once more and the cycle repeats itself again and again overnight.
In OSAHS, the apnoeas can last for several seconds and in severe cases the cycle of apnoeas and broken sleep is repeated hundreds of times per night. Most sufferers are unaware of their disrupted sleep but awaken unrefreshed, feeling sleepy and in need of further refreshing sleep.
Who gets OSAHS?
While OSAHS is more common in overweight middle-aged males who snore, it can also affect females, although female hormones and a difference in throat structures may protect women until the menopause. Narrowing of the back of the throat and the upper airway can also contribute to the risk of getting OSAHS, even in people who are not overweight or middle-aged. In such people a small jaw, enlarged tongue, big tonsils and big soft palate help to block the upper airway in deep sleep, making OSAHS more likely to occur. Several of these problems can be present in any person at the same time.
The use of alcohol, sleeping tablets and tranquillisers prior to sleep relaxes the upper airway muscles and makes OSAHS worse. Alcohol can also reduce the brain’s response to an apnoea which in turn leads to longer and more severe apnoeas in people who would otherwise have only mild OSAHS and who would otherwise only snore.
What are the symptoms of OSAHS?
Most people with OSAHS snore loudly and breathing during sleep may be laboured and noisy. Sleeping partners may report multiple apnoeas which often end in deep gasping and loud snorting. Sufferers may report waking for short periods after struggling for breath. Symptoms are often worse when lying on the back in deepest sleep.
Although a person with OSAHS may not be aware of the many arousals from deep sleep, they suffer from poor quality sleep in spite of long periods of time spent in bed. Such people wake feeling that they haven’t had a full refreshing night’s sleep. They report difficulty maintaining concentration during the day, have a poor memory, and suffer from excessive daytime sleepiness.
At first an OSAHS sufferer may be sleepy only when seated and relaxed, e.g. watching TV, but eventually sleepiness becomes so severe that car accidents and accidents in the workplace occur. Other symptoms of OSAHS include morning headache, nocturia, depression, short temper, grumpiness, personality change, and impotence in males leading to loss of interest in sex.
What are the consequences of untreated OSAHS?
The most serious potential consequences of untreated OSAHS are road traffic accidents and accidents at work because of sleepiness. Untreated OSAHS is associated with a sixfold increase in risk of such accidents.
Patients may also experience difficulties with concentration due to tiredness, increased irritability and depression. There is evidence that patients with OSAHS have an increased risk of high blood pressure and may have a slightly increased risk of angina, heart attacks and strokes.
Because OSAHS significantly increases the risk of road traffic accidents patients must not drive if experiencing excessive daytime sleepiness.Patients must inform the DVLA in Swansea following diagnosis of the condition. In most cases, the DVLA are happy to allow car drivers to continue driving once they are established on a successful therapy.
How is OSAHS assessed?
When a person is suspected to have OSAHS, their doctor will ask questions about waking and sleeping habits and will make a physical examination. Reports from the sleeping partner or household member about any apnoeas are extremely helpful.
Referral to a sleep disorders centre for an overnight sleep study will probably be required to confirm the diagnosis of OSAHS and to allow its severity to be measured.
During a sleep study, sleep quality and breathing are measured overnight by a computer while the person sleeps. Procedures in different hospitals vary but small coin-sized electrodes may be taped to special points on the scalp, face, chest and legs.
Chest and stomach wall movements are also measured and a special sensor placed on the upper lip measures airflow. The oxygen level in the blood is assessed by a device placed on the finger or the ear-lobe. None of these procedures is uncomfortable or painful.
How is OSAHS treated?
The simplest treatment is to lose weight. This is best done by cutting down on all foods, especially fatty foods, sweet things and alcohol. Alcohol within 6 hours of bedtime should be avoided as it contributes to OSAHS symptoms. If these measures are not enough, the best form of treatment is continuous positive airway pressure (CPAP) therapy in which a gentle flow of air is applied through the nose at night keeping the pressure in the throat above atmospheric pressure and stopping the throat narrowing to prevent breathing pauses and snoring.
Other forms of treatment include gumshield-like devices (mandibular repositioning devices) which attempt to keep the airway clear by moving the jaw forward. Surgery to remove excess tissue from the throat is another option, but it is not recommended. Both of these alternatives are less effective than CPAP and not appropriate for all patients.
Adapted from SIGN 73. Management of obstructive sleep apnoea/hypopnoea syndrome in adults – A national clinical guideline. Edinburgh: Scottish Intercollegiate Guidelines Network, 2003.
|Resources for patients|
The Scottish Association for Sleep Apnoea
SATA (The Sleep Apnoea Trust)
American Sleep Apnoea Association