Sleep Apnoea - The Fatigue of Sleep

What is Sleep Apnoea?

Sleep Apnoea is a common disorder that often goes undiagnosed. Most people do not even know they have the condition as it occurs during the night, whilst you are sleeping. In a nut shell, sleep apnoea is a chronic condition that disrupts the quality of your sleep due to pauses in breathing or complete cessation of breathing for up to one minute.

The mechanism behind this condition is best explained by understanding the process of inhalation (breathing in) and exhalation (breathing out). The airway; consisting of the nose, throat, mouth and windpipe, allows the flow of oxygen into your lungs when you inhale (take a breath in) and allows the escape of carbon dioxide when you exhale (take a breath out).

Depending upon how severe the condition, you may experience a narrow or complete blockage of the airway during your sleep, making it substantially more difficult for the air to make its way into your lungs. The air that can manage to squeeze its way through this partial blockage may be the sound we commonly recognise as snoring. When the airway is completely blocked and there is no airflow, this is known as apnoea. At this point there is a decrease in the level of oxygen in your blood which results in signalling from the brain to disrupt your sleep to assist in re-opening of the airway (sometimes obstructed breathing can end in a gasp for air).

Once you have returned to sleep, the normal breathing cycle continues until the next episode of apnoea occurs. This may occur between 1 and 100 times every night; it may range from seconds through to minutes. Due to this poor quality of sleep, people who suffer from this condition often feel unrefreshed in the morning; have poorer concentration throughout the day, higher levels of fatigue and excessive daytime sleepiness.

The full name of this condition is known as Obstructive Sleep Apnoea (OSA) and can be categorised in terms of its severity, referring to the guide below:

• Normal - less than 5 interruptions an hour
• Mild sleep apnoea - between 5 and 15 interruptions an hour
• Moderate sleep apnoea - between 15 and 30 interruptions an hour
• Severe sleep apnoea - over 30 interruptions an hour

Causes of Sleep Apnoea

Obesity is one of the most common causes of sleep apnoea, especially around the abdomen and neck, although OSA can occur in people who are not overweight or obese. Other risk factors for sleep apnoea include:

• Large neck circumference (>43cm for men and >40cm for women)
• Sedatives or sleeping tablets
• Excessive alcohol consumption
• Cigarette smoking
• Family history of OSA
• Over 65 years
• Reduced thyroid production
• Facial abnormalities (e.g., abnormal bite, small jaw, etc)

Signs and Symptoms

• Snoring
• Dry mouth
• Morning headaches
• Fatigue, poor concentration and excessive daytime sleepiness
• Behavioural changes (e.g., anxiety, irritability, moody)
• Rapid weight gain or difficulty in losing weight
• Increased frequency of toileting during the night

Statistics

Obstructive Sleep Apnoea primarily affects men and is more common with age. It is thought that 9% of women and 25% of men in Australia are affected by the condition. The prevalence of OSA in Australia is thought to be increasing in part, due to the ‘obesity epidemic’.  Research shows that OSA is a known case for sudden death at night and even mild interruptions to sleep can result in an increase in mortality rate. Individuals who suffer from the condition are more likely to be involved in motor vehicle accidents due to the excessive fatigue, lethargy and poor concentration associated with the condition.

Diagnosis

Your doctor will do a physical exam and check your mouth, nose and throat for large or extra tissue. Your doctor may order a sleep study which is performed in a hospital or sleep centre. The most common sleep recording to diagnose sleep apnoea is called a polysomnogram or PSG. This test records brain and muscle activity, eye movement, breathing and heart rate, oxygen levels in the blood and air movement into your lungs.

Treatment Options

The most appropriate treatment option will depend on the severity of the OSA, age, body weight, medical history and the anatomy of your upper airway. It is best to see a sleep specialist who specialises in the treatment of patients with this condition and other sleep related disorders. Treatment should always be individualised and can involve many different options.

For Example:

• Continuous Positive Airway Pressure (CPAP) – is the most successful intervention for OSA. It involves using a small machine to pump air at a continuous pressure through a mask worn over you mouth, nose or both. This will hold your airway open during the night and allow normal breathing.
• Provent Therapy – a new device (small and disposable) that covers the nostrils. This may be a more suitable option to CPAP.
• Weight loss – a loss of approximately 5 – 10 kilograms is often enough to reduce the severity of the condition and make it possible to reduce the level of pressure needed with CPAP treatment.
• Lifestyle – smoking cessation and reduction in alcohol intake.
• Dental/Oral Appliances – a Mandibular Advancement Splint (MAS) is sometimes prescribed for those with mild OSA. These fit in your mouth in a similar way to that of a mouth-guard.
• Surgery – The long term success rate of surgery is low. The use of a CPAP machine is now considered the ‘gold standard’ for treatment in this area.

Do I need help?

To help determine whether you need medical treatment, answer the following questions.

• Do you gasp, choke or stop breathing during sleeping?
• Do you snore loudly at night?
• Do you feel tired and un-refreshed during the day?
• Do you have a dry mouth and/or headache in the morning?
• Are you overweight?
• Do you have a neck girth over 40cm (women) and 43cm (men)?
• Do you have a family history of sleep apnoea?

If you have answered ‘yes’ to any of these questions you may have or be at risk of having sleep apnoea and you should see your Doctor or visit a sleep disorders clinic.