What is sleep apnoea (OSA)?
Obstructive sleep apnoea (OSA) is a common condition. Apnoea literally means absence of breath and an obstructive apnoea episode is defined as the absence of airflow for at least 10 seconds. Yet people often don’t even know they have it.
How does obstructive sleep apnoea occur?
OSA occurs when tissues in the upper airways come too close to each other while you’re sleep, temporarily blocking the inflow of air. During normal sleep, the muscles lining the upper throat relax slightly but stay strong enough to keep the airway open, allowing air in and out of the lungs. Some people have a narrower airway and the relaxation of these muscles during sleep causes it to close. Loud snoring and laboured breathing are the result. When complete blockage of the airway occurs, air cannot reach the lungs and the sufferer wakes briefly. This wakefulness restores the airway and sleep returns. This cycle can be repeated as many as 500 times each night, leaving you tired and lethargic next day, and desperate for a good night’s sleep.
What are the symptoms of sleep apnoea?
During the day:
- Excessive tiredness eg, inability to stay awake while reading or watching television
- Waking without feeling refreshed
- Morning headache
During the night:
- Snoring, usually loud, habitual, and bothersome to others, is found in almost all patients with OSA. However, not all snorers suffer from OSA.
- Pauses in breathing that often interrupt the snoring and end with a snort
- Gasping and choking sensations that intermittently arouse the sufferer from sleep
- Restless sleep (insomnia), with people often complaining of frequent arousal and tossing/turning during the night
How is obstructive sleep apnoea treated?
Several simple lifestyle changes can reduce the symptoms in many patients:
- Weight loss (via meal replacement programs, drugs or surgery)
- Giving up smoking
- Avoiding alcohol and sedative medications, particularly before sleep
- If symptoms are worse in one position eg, when lying flat on your back, avoiding this position may help Many patients with OSA will require further treatment.
- Oral appliances, worn at night. They pull the jaw forward and are designed to prevent the collapse of the upper airway during sleep. They can be used for mild and moderate disease.
- Continuous positive airway pressure (CPAP) via nasal mask. This is a machine that blows air through a mask into your mouth and nose during sleep. The pressure of the air keeps the throat open, preventing the airway from collapsing. It is the most effective treatment for OSA, reducing daytime sleepiness and improving sleep quality. However, some people find the mask or feeling of pressure difficult to tolerate.
- Surgical treatment is rarely used. Several procedures have been trialled, including uvulopatatopharyngoplasty (UPPP), which is designed to remove some of the soft tissues of the throat that collapse the airway during sleep. However, while UPPP may reduce snoring, it is often ineffective at treating true obstructive sleep apnoea.
What happens if left untreated?
If untreated, OSA may have serious consequences. It affects the cardiovascular system due to the periods of poor oxygenation during sleep and the stress on the body during attempts to re-initiate breathing. This may result in heart failure, arrhythmias (abnormal heart rhythms), or hypertension (high blood pressure). Poor sleep due to recurrent arousals may result in excessive daytime sleepiness, personality changes, memory loss and intellectual impairment.