What is sleep apnea?
Sleep apnea refers to interruption of breathing during sleep. The most common form of sleep apnea is obstructive sleep apnea (OSA). In OSA, the muscles of the soft palate around the base of the tongue and the uvula relax, obstructing the airway. The airway obstruction causes the level of oxygen in the blood to fall leading to a condition, termed hypoxia which ultimately increase the stress on the heart, elevates blood pressure and prevents the patient from entering the restful and restorative stage of sleep. In other words, sleep apnea causes deprivation of quality sleep.

Aftermath and association with other diseases
People with untreated sleep apnea stop breathing repeatedly during their sleep, sometimes hundreds of times during the night and often for a minute or longer. People with apnea may suffer from early-morning headaches and feel excessively sleepy throughout the day. Hallucinations sometimes occur while the patient is awake, but feeling extremely sleepy. Memory deterioration, personality changes and impotence are common. Rapid weight gain, often approaching obesity frequently occur.

Apnea patients have twice the usual prevalence of hypertension, three times as much heart diseases, and four times as much cerebrovascular diseases. Other potential consequences include stroke, neuropsychiatric problems, cognitive impairment, sexual dysfunction and injury due to accidents.

Symptoms of sleep apnea
The symptoms of OSA include loud snoring and/or abnormal pattern of snoring with pauses and gaps. Other symptoms include excessive daytime sleepiness, memory changes, depression and irritability. In some patients sleep apnea can contribute to high blood pressure, heart failure, stroke and heart attack.

OSA typically affects middle-age, over-weight men and may affect women in later age. OSA can be aggravated by alcohol, sleeping pills and tranquilizers taken at bedtime.

Diagnosis
“Sleep laboratories” are now available to monitor different stages of sleep apnea, determine the type (obstructive or central) and severity of sleep apnea, and design treatment.

Treatment
General measures in treating OSA include losing excessive weight, avoiding alcohol and sedatives, sleeping on one side, and medications to relieve nasal congestion. More specific treatments include CPAP (Continuous Positive Airway Pressure), oral appliance to open the airway, and ENT surgery -- UPPP (Uvulo Palato Pharyngo Plasty) where a surgeon removes excessive soft tissue in the back of the throat to relieve obstruction.

CPAP is an effective treatment for sleep apnea. A mask is worn over the nose during sleep while compressed air is gently forced through the nose to keep in airway open.

If you suspect you may have sleep apnea, the first thing to do is to consult a doctor. Bring with you a record of your sleep, fatigue levels throughout the day, and any other symptoms you might be having. Ask your bed partner if s/he notices that you snore heavily, choke, gasp or stop breathing during sleep.

Second line treatment of sleep apnea is dental appliances, which reposition the lower jaw and tongue, and upper airway surgery to remove tissue in the airway. In general, these approaches are most helpful for mild disease or heavy snoring.

Lifestyle changes are effective ways of mitigation of symptoms of sleep apnea. Here are some tips that may help reduce apnea severity.

*Lost weight: If you are overweight, this is the most important action you can take to cure your sleep apnea.

*Avoid alcohol: It causes frequent nighttime awakenings, and makes the upper airway breathing muscles relax.

*Quite smoking Cigarette smoking worsens swelling in the upper airway, making apnea (and snoring) worse.

Some patients with mild sleep apnea or heavy snoring have fewer breathing problems when they are lying on their sides instead of their backs.

Treatment facilities
Japan-Bangladesh Friendship Hospital has started ‘Sleep Disorder Clinic’ -- the first of its kind sleep laboratory in our country. They have introduced the monitoring of sleep disorders (Polysomnography) with some highly trained pulmonologists and otorhinolaryngologists.

The writer is a Registrar of ENT & Head-Neck Surgery Department of Sir Salimullah Medical College and Mitford Hospital.