Breathing Disorders of Sleep

The major breathing disorders of sleep are snoring, obstructive sleep apnoea and sleep-related hypoventilation

Habitual snoring occurs in about 25% of adults. It is caused by vibration of relaxed soft tissues in the upper airway during sleep. Snoring can be an embarrassing social problem and can cause marital stress. By itself, snoring has few direct health consequences. However, snoring may be a symptom of obstructive sleep apnoea, and this has more serious health implications.

Obstructive sleep apnoea is characterised by repeated episodes of partial or complete obstruction to breathing. This is caused by narrowing or obstruction of the throat when the muscles supporting the upper airway relax during sleep. In most individuals, sleep apnoea is associated with loud snoring. The obstructions to breathing may be obvious to the individual’s bed partner as brief periods of silence between bouts of snoring. A consequence of these obstructions is repeated momentary interruptions to sleep. Occasionally these result in sudden awakenings from sleep, but often they are so brief (less than 15 seconds) that the individual may be unaware, except they are unrefreshed by sleep and sleepy during the day. Sleep apnoea is associated with an increased risk of accidents, hypertension, heart attack and strokes. It affects between 2 and 4% of adults, and may affect children. Effective treatments are available and include (where applicable) changes in lifestyle, dental appliances, continuous positive airway pressure (CPAP) therapy, and in some cases surgery. These treatments also control snoring.

Sleep-related hypoventilation refers to inadequate breathing during sleep due to reduced or absent respiratory effort, and is usually seen in the context of weakness of respiratory muscles, deformity of the chest wall, morbid obesity or advanced lung disease. If sufficiently severe, sleep-related hypoventilation can result in respiratory and right heart failure. The problem can be effectively treated and life expectancy and quality substantially improved by non-invasive ventilatory assistance (NIV) during sleep, delivered from a portable ventilator via a face or nose mask, at home. The Institute has extensive expertise in this treatment.