Sleep, Snoring and Sleep Apnoea There has been a lot of interest in the subject of sleep recently and rightly so, because we spend practically one thirds of our life sleeping! That is unless you an insomniac of course, or you have one of those sleep disorders. Sleep is a state of reversible unconsciousness, an active process controlled by the brain but influenced by several factors. Sleep is essential for growth, particularly in children. It is during sleep that the growth hormone is secreted that helps a child to grow. In adults, the growth hormone has a reparative function. It restores and regenerates the daily wear and tear of the body tissues. Sleep is also important for memory and brain development. Normal sleep duration in an average adult may vary widely. The mean is between 323 – 470 minutes. There are many sleep related disorders. Three common sleep related disorders caused by obstruction in the nasal passage or the upper airway are; 1. snoring, 2. upper airway resistance syndrome (UARS) and 3. obstructive sleep apnoea (OSA).
- Snoring is an undesirable sound that occurs during sleep. It is a sign of incomplete airway obstruction in the nasal cavity, at the level of the soft palate or the base of the tongue. Snoring and OSA are related. More than 75% of the snorers may have OSA.
- Upper Airway Resistance Syndrome (UARS) is a condition where there is increased resistance of the airflow through the nose due to a narrow air passage. This results in increased effort in breathing leading to repeat arousals and sleep fragmentation.
- Obstructive Sleep Apnoea (OSA) is a cyclical airway obstruction due to upper airway collapse. The obstructions lead to episodes of apnoea or hypopnoea. These episodes result in less oxygen reaching the lungs and consequently the brain. As a result the brain remains active during sleep to ensure the oxygen does not fall to dangerous levels. When an apnoic spell occurs, the brain triggers a response which awakens the subject overcoming the apnoeic spell and the subect goes back to sleep. And the cycle of OSA starts again. Repeated episodes of apnoea and hypopnoea, which may be in excess of 30 an hour, may lead to severe sleep fragmentation.
The total number of apnoeic and hypopnoea (AHI index) episodes an hour are used to quantify the severity of sleep apnoea. If the episodes are 5-14 an hour is considered mild OSA, if 15-29 it is moderate and if it is more than 30 episodes an hour it is classified as severe OSA. Snoring and OSA can lead to social and marital problems, excessive day time somnolence (EDS) and stress on the heart and the brain leading to hypertension, atherosclerosis, ischemic heart disease, heart attacks and increased incidence of stroke. In Singapore the incidence of OSA is about 15% of the population. Patients at risk are the obese, the elderly, patients with anatomical abnormalities of the upper airway and craniofacial abnormalities. Alcohol and smoking are also risk factors. So how do you know if you have OSA? If you snore and do not sleep well, wake up frequently at night, feel excessively sleepy and tired during the day, it is possible you may have OSA. Excessive Day Time Somnolence can be graded using the Epsworth Sleepiness Scale which is available online. If you score anything more than 10 this needs to be looked into.
Surgery for Snoring and Sleep Apnoea
- Tonsillectomy and adenoidectomy
- Surgery of the nasal septum and inferior turbinates
- Radiofrequency of the soft palate
- Uvulopharyngopalatoplasty (UPPP)
- Tongue base reduction surgery