What is Obstructive Sleep Apnoea

People who suffer from Obstructive Sleep Apnoea (OSA) reduce or stop their breathing for short periods while sleeping (Apnoea literally means absence of breath). This can happen many times during sleep. These breathing stoppages interrupt sleep, resulting in poor sleep quality and excessive sleepiness during the day. Because these events occur during sleep, a person suffering from OSA is usually unaware of them and is often the last one to know what is happening.

In deep sleep, the muscles of the throat relax and this may reduce the space at the back of the tongue, through which air must pass to reach the lungs. Normally this doesn’t cause any problems with breathing. In OSA, however, complete relaxation of the throat muscles may cause blockage of the upper airway so that breathing stops temporarily.

Such an episode is called an apnoea. During an apnoea, people with OSA make constant efforts to breathe through their obstructed airway. With no passage of air into the lungs, the blood oxygen level begins to fall. This signals the brain to rouse the person from deep relaxed sleep so that the muscle tone returns, the upper airway reopens and breathing begins again.

Unfortunately, when a person with OSA falls back into deep sleep, the muscles again relax and the cycle repeats itself again and again overnight.

In OSA, the apnoeas can last for ten or more seconds and the cycle of apnoeas and broken sleep is repeated hundreds of times per night in severe cases. Most sufferers are unaware of their disrupted sleep but awaken unrefreshed, feeling tired and needing more sleep.

Open airwayClosed airway
 OSA is more common in overweight middle-aged men who snore although it can also affect women and men at any age.

Female hormones and a difference in throat structures may protect women until the menopause. Narrowing of the throat and the upper airway can also contribute to the risk of getting OSA even in people who are not overweight or middle-aged. In such people, a blocked nose, small jaw, enlarged tongue, big tonsils or uvula may contribute to blockage of the upper airway in deep sleep, making OSA more likely.

The use of alcohol, sleeping tablets and tranquillisers prior to sleep tend to worsen OSA by further relaxing the upper airway muscles. In addition, alcohol can reduce the brain’s response to apnoea, which may increase the length of the apnoeas events or may cause obstructive sleep apnoea in an individual who would otherwise only snore.

Most people with OSA snore loudly and breathing during sleep may be laboured and noisy. Sleeping partners may report multiple apnoeas lasting up to 90 seconds which often end in deep gasping and loud snorting. Sufferers may report waking for short periods after struggling for breath. OSA is often worse during deep sleep or when the person sleeps lying on their back.

Symptoms

Although a person with OSA may not be aware of the many arousals from deep sleep, the sleep disruption may result in a perception of poor quality sleep despite 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.

An OSA sufferer may be sleepy only when seated and relaxed, e.g. watching TV, but with more severe sleep apnoea, sleepiness becomes more pervasive during the day so that car and workplace accidents may occur.

Other symptoms of OSA include morning headache, depression, short temper, grumpiness, personality change, loss of interest in sex, and impotence in males.

Problems Accociated with OSA

Diagnosing Sleep Apnoea

In a person suspected of having OSA, their doctor will need to ask questions about waking and sleeping habits. Reports from the sleeping partner or other household members about any apnoeas are extremely helpful.

Referral to a sleep disorders specialist and an overnight sleep study will assist with the diagnosis of OSA and measurement of its severity.

During a sleep study, sleep quality, quantity and breathing are measured by a computer overnight while the person sleeps. Small electrodes are attached to special points on the scalp, face, chest and legs. There are also chest and stomach bands to detect breathing movements and a sensor placed on the upper lip to measure airflow. The oxygen level in the blood is assessed by a device placed on the finger or the ear-lobe. The wires and sensors are generally not painful or uncomfortable, but may feel unfamiliar or restrict movement during the night’s sleep. Although patients often worry that the recording equipment will interfere with sleep, usually the information obtained is sufficient to make a diagnosis.

More than one overnight study may be needed. The first is to measure what is going on, and the second is to start treatment if needed and assess the optimum pump pressure.

Treatment

The chosen form of treatment depends on the severity of OSA and patient factors.

General guidelines:

  • In an overweight person, weight loss is an important part of treatment. Even a small loss of weight can lead to improvement in symptoms of OSA.
  • Avoiding alcohol up to two hours before going to sleep and not using any sleeping tablets or tranquillisers can also help.
  • Nasal obstruction may respond to nasal decongestant sprays and smoking cessation.
  • For the patients whose sleep apnoea is worsened by lying on their back, positioning devices encourage sleep in other positions but are of limited value in very severe OSA.

Specific Treatments include:

  • Continuous Positive Airway Pressure (CPAP) therapy
  • Mandibular Advancement Splints (MAS)
  • Surgery
  • Newer treatments are also being developed. 
 
SleepEquip recommends consulation with a Registered Physician or healthcare professional for the best advice about Obstructive Sleep Apnoea. 
 
Any medical information is provided as general information only. It is not a substitute for advice from a registered physician or other healthcare professional. Product information is also provided as general information. It is not a substitute for user manuals or other documentation supplied with the manufacturer's products nor a substitute for advice from a registered physician or other healthcare professional.