What is Obstructive Sleep Apnoea?
Obstructive sleep apnoea occurs when the tongue and soft palate collapses (obstructs) onto the back of the throat and partially or completely blocks the upper airway during sleep. This causes the person to stop breathing momentarily (this is called an apnoea) and also restricts the flow of oxygen in the blood. When the brain's oxygen levels falls low enough, it will briefly awaken the individual from sleep so the airway can be reopened. A deep gasping, choking, or snorting usually signifies this as the person struggles to breathe again. The individual will usually fall back to sleep again and may not be aware this has happened. It is usually their concerned bed partner who notices. These episodes may occur many times during the night and disrupts normal sleep and starves the body of vital oxygen. In severe cases, individuals may have more than 30 obstructions in an hour.
How serious is Obstructive Sleep Apnoea?
Individuals with untreated obstructive sleep apnoea have an increased risk of developing a number of medical conditions:
- High blood pressure
- Heart disease
- Heart attack
- Irregular heartbeats
Scientific evidence shows that individuals with moderate to severe sleep apnoea are at an increased risk of death due to one of the above medical conditions.
Obstructive sleep apnoea may also contribute to driving and work-related accidents due to excessive daytime sleepiness, which affects concentration, cognition, memory and ability to work effectively. People with obstructive sleep apnoea are at least 4 times more likely to have a motor vehicle accident. The drowsiness caused by obstructive sleep apnoea is comparable to the consumption of alcohol and drugs.
Obstructive sleep apnoea can also affect families. Snoring can keep your bed partner awake. Some partners try to stay awake to ensure their partner starts breathing again every time they stop breathing. Lack of sleep can place strain on a relationship.
How common is Obstructive Sleep Apnoea?
Obstructive sleep apnoea affects 9% of males and 5% of females. It is commonly associated with snoring and obesity. Individuals of all ages including children can be affected by obstructive sleep apnoea. In adults, sleep apnoea is more common in middle age. In children, obstructive sleep apnoea is often the result of enlarged tonsils or adenoids or some orofacial abnormality.
Many individuals with obstructive sleep apnoea are aware they snore and feel tired or fatigued during the day but are unaware of a potentially serious medical problem, which may exist. Therefore, many individuals with obstructive sleep apnoea remain undiagnosed.
Signs and symptoms of Obstructive Sleep Apnoea
- Loud snoring
- Gasping or choking at night
- Stop breathing (apnoeas)
- Unrefreshed sleep
- Excessive daytime sleepiness
- Tired or fatigued during the day
- Problems with memory or concentration
- Morning headaches
- Awakening with a dry mouth or sore throat
- Fall asleep sitting, reading, watching TV or driving
- Increased frequency of urination at night
- Irritability, depression, mood, behavioural and personality changes
- Impotence or decreased sex drive
Risk Factors for Obstructive Sleep Apnoea
- High blood pressure
- Heart condition
- Male gender
- Menopausal women
- Greater than 40 years of age
- Alcohol, sedative or tranquiliser use
- Family history of obstructive sleep apnoea
- Abnormality of the upper airway or orofacial tissues
How is Obstructive Sleep Apnoea diagnosed?
If you believe you have the symptoms of obstructive sleep apnoea, consult your medical GP. Your GP will typically ask you regarding common signs and symptoms and carry out a physical examination. If your history and examination suggests you have obstructive sleep apnoea, your GP must then refer you for a sleep study under the care of a specialist sleep physician. The sleep study is necessary to confirm the presence and severity of obstructive sleep apnoea in order to establish a diagnosis. This is important, as your diagnosis will determine the best treatment option for you.
A sleep study is performed overnight in either a sleep laboratory or at home using a portable device. Although a home based sleep study may be more convenient, current evidence suggest that a laboratory based sleep study is more accurate. During a sleep study, electrodes and sensors are attached to the scalp, face, chest, legs and finger. The sleep study will record the following information:
- Blood oxygen levels
- Body position
- Brain waves
- Breathing rate
- Electrical activity of muscles
- Eye movement
- Leg movement
- Heart rate
- Number of times breathing stops
- Teeth grinding
A sleep study may also detect other sleep disorders such as narcolepsy, periodic limb movement disorder, central sleep apnoea and sleep bruxism.
PATIENTS MUST HAVE A CURRENT SLEEP STUDY (WITHIN 5 YEARS) PRIOR TO FABRICATION OF AN ORAL APPLIANCE FOR SNORING AND OBSTRUCTIVE SLEEP APNOEA. TREATMENT CANNOT BE COMMENCED WITHOUT THIS INFORMATION.