Sleep-disordered Breathing and Snoring

Sleep-disordered breathing refers to a spectrum of conditions characterised by abnormal breathing during sleep. This can range from mild simple snoring to Obstructive Sleep Apnoea (OSA).

In simple snoring, there is mild narrowing of the upper airways causing noisy breathing during sleep but no associated sleep disturbance or impairment of daytime function.

In contrast, patients with OSA have more severe airway obstruction during sleep which results in significant sleep disturbance, repeated cycles of low oxygenation and impairment of daytime function.

In a local study, approximately 24 percent of adults are loud habitual snorers and about 15 percent of adults are estimated to have OSA (Puvanendran K et al, Sleep Research Online 1999).

Snoring is caused by the vibration or flapping of tissues lining the upper air passages. This may be due to:

• Relaxation of muscles causing the walls of the upper airway to fall together, causing them to vibrate.
• Swelling of the tissue in the walls, for example, due to anatomical or injury may cause narrowing.
• The tongue falls back into the throat when sleeping on the back, contributing to the snoring.
• Nasal blockage such as nasal allergy or deformities of the nasal septum (the cartilage partition between the two sides of the nose) can cause poor nasal airflow and set the soft tissues of the palate (roof of the mouth) and throat vibrating.

Individuals with OSA have a narrower and more collapsible upper airway causing repeated upper airway obstruction during sleep. When breathing stops, the level of oxygen in the bloodstream falls. The brain senses this decrease in oxygen and rouses the person from sleep. With awakening, the muscles at the back of the throat become more active and hold the airway open so that breathing can resume.

Any condition that contributes to the narrowing at the back of the throat such as enlarged tonsils or adenoids favour the development of OSA.

Large tonsils are the most common cause of snoring and sleep apnoea in infants. They can also be the occasional cause of problems in adults although nasal and soft palate problems are the more common causes of adult snoring.

Other factors which may influence the snoring condition and the development of OSA are obesity, ageing and associated loss of general muscle tone, throat congestion due to reflux of stomach acid (heartburn); and the effects of alcohol, sedatives and smoking.

In obesity, excessive fat accumulation in the upper airway may amplify an existing anatomic narrowing of the upper airway that was causing minimal obstruction previously.

Snoring and OSA are also more common among males and in individuals with a genetic predisposition leading to facial and jaw abnormalities.

Effective treatment is available for almost all patients. Treatment of both snoring and OSA requires a multidisciplinary approach.

Treatment for snoring

The treatment of snoring is divided into medical and surgical options. The treatment choice is individualised. In the treatment of snoring, a ’staged’ approach is often used, which generally involves medical therapy first, followed by consideration of surgery, if medical therapy is unsuccessful.

Medical

For patients with snoring and mild OSA, a conservative approach is usually recommended. These include:

• Weight loss
• Avoidance of alcohol
• Sedative medications. Sedatives relax the muscles at the back of the throat and may depress breathing.
• Nasal congestion is also treated with medications. Nasal obstruction increases the frequency of snoring and disordered breathing during sleep.
• Sleeping on the sides rather than on the back. This position prevents the tongue and soft palate from collapsing against the back of the throat and blocking the airway.

Surgical

Surgical procedures for the treatment of snoring may include nasal, palatal, jaw, tongue and neck surgery. The surgical procedure recommended will depend on the location of the tissues contributing to the snoring.

Treatment for OSA

Indications for treatment of OSA include excessive daytime sleepiness affecting daytime performance, moderate to severe OSA and cardiovascular complications (hypertension, ischaemic heart disease, irregular heart rhythm and stroke).

Treatment of OSA can improve daytime sleepiness, prevent cardiovascular complications, decrease sleep apnoea-related road traffic and workplace accidents, and improve quality of life.

A medical device called Continuous Positive Airway Pressure (CPAP) may be recommended for patients with moderate to severe OSA. This device delivers room air to the nose and back of the throat at a slightly elevated pressure to prevent the airway from collapsing during sleep. CPAP is safe, generally well-tolerated and highly effective. This device must be worn nightly and long-term CPAP compliance is essential for its effectiveness.

Dental appliances that reposition the lower jaw and tongue have been helpful in some patients with mild OSA and snoring. Dental appliances have to be worn every night. Dental and lower jaw joint side effects may prevent compliance.

Surgery may be recommended for treatment of OSA for some individuals. Surgery is individualised and may range from procedures designed to open the nose and enlarge the back of the throat. Medications are ineffective in treating OSA.

Self/Home care

Some useful suggestions for snorers:

• Reduce weight if you are obese.
• Avoid taking sleeping pills/ sedatives. Certain sleeping pills may cause the upper airway to relax, leading to snoring.
• Avoid consuming alcohol after 6pm. Alcohol causes relaxation of muscles of the upper airway.
• Sleep on your side and avoid sleeping on the back.
• Quit smoking. Smoking causes swelling of the tissues of the upper airway, which results in snoring.
• Allow your bed partner to fall asleep before retiring to bed.
• Provide earplugs for your bed partner.