Understanding Sleep Apnea
What is Sleep Apnea?
Apnea is the combination of two Greek words, a ("without") and pnea ("air"). Sleep apnea refers to the loss of breath during sleep. This results in a depletion of oxygen and a build up of carbon dioxide in the lungs and blood.
Snoring is the most obvious event associated with sleep apnea. Snoring results from a narrow airway which produces a rapid increase in airflow. This causes a suction on the sidewalls of the throat. Resistance to collapse results in the vibration of these elastic tissues and produces a snore sound. With sufficient suction, collapse of the airway (apnea) follows.
This is similar to using a pinched straw to drink from a glass. Like a pinched straw, the airway collapses and no air is introduced into the lungs. The person continues to sleep until the buildup of carbon dioxide triggers an arousal. This arousal may be less than sufficient to produce alertness. Often the patient will simply lighten his sleep for a few seconds, open his airway and return to sleep, and the collapsing process will repeat. The usual cycle is about once per minute. Therefore, it is possible for a person to experience 500 to 600 episodes of sleep apnea each night in more severe cases. The bed partner becomes aware of this problem because of pauses in air flow that are followed by gasping. They may become concerned that their mate is about to die in their sleep from choking.
What are the Effects of Obstructive Sleep Apnea?
Sleep apnea is a progressive disease. As snoring progresses to apnea, respiratory pauses will begin to develop. Initially this may be only a few per night. The patient will be totally unaware of any change in this ability to function. As the number of apneic events increase, both physical and mental symptoms develop. These are usually not noted until there are at least 50 or more events per night.
The cognitive (mental) functions involved include:
- Difficulty with concentration
- Falling asleep inappropriately
- Poor memory
- Increased irritability
- Decreased energy
- Significant fatigue
- Some depression
- Rapid sleep onset
- Avoidance of social events
In addition to these deteriorations in mental function, there will also be some physical symptoms that will appear. These include:
- Chronic weight gain
- Tossing and turning in sleep
- A tired sleepy look in the face
- Loud snoring
- Significant fatigue
- Mumbling in sleep
- Drooling on the pillow
- Frequent trips to the bathroom at night
Long term effects of sleep apnea include:
- Increased risk of heart attack, stroke & angina pectoris (chest pains)
- Poor job performance
- Impaired family relationships
Symptoms vary among patients, but most will have three or more of the above complaints. These problems are generally reversible with treatment.
Who is at Risk For Developing Obstructive Sleep Apnea?
A typical sleep apnea patient can be described as falling into a risk group characterized by predictive factors.
- Loud Snoring
This is snoring which is socially objectionable and usually makes the bed partner unhappy. It is often punctuated by snorts and gasps. The snoring is made worse by fatigue, sleep deprivation, use of alcohol or hypnotic medications and weight gain.
- Male Predominance
80 to 90% of sleep apnea patients are males. This would appear to be hormonally related. Injections of male hormone into males makes the condition worse or may induce sleep apnea in some cases. The taking of female hormones by men appears to lessen the symptoms of obstructive sleep apnea.
Most sleep apnea patients are over the age of 35, however, sleep apnea may develop at any age, including infancy.
- Weight Gain
With weight gain, snoring usually worsens and sleep apnea is also aggravated. This becomes a positive feedback loop. The more weight one gains, the worse the sleep apnea becomes. The worse the sleep apnea, the more you slow down and become inactive, which results in further weight gain. Most sleep apnea patients have a neck size of 16½ inches or greater. Weight gain appears to be associated with deposits of fat inside the neck which press on the airway and further restrict the size of the airway passage.
The tendency for snoring and sleep apnea is often inherited.
- Alcohol and sleeping pills
Use of alcohol or sleeping pills can cause or worsen sleep apnea in a susceptible patient. If you snore, the drugs can induce or worsen sleep apnea.
A typical patient is a loud snoring male over the age of 35 who has gained weight and has three or more other symptoms of sleep apnea. There is usually a family history of snoring, especially if the patient is a female.
How Do I Know If I Have Obstructive Sleep Apnea?
The only definitive test for obstructive sleep apnea is an overnight polysomnogram which measures breathing effort, airflow, brain waves, eye movements, muscle tone, heart rate, breath sounds and leg movements across a night's sleep. This data is then analyzed to detect sleep disturbance, breathing impairment, oxygen loss and any cardiac irregularities induced by obstruction of your airway during sleep. With this data we can quantify the severity of the problem and determine if a significant disorder does exist.
If you are scheduled for an overnight polysomnogram, learn more about preparation instructions.
If I Have Obstructive Sleep Apnea, Is There a Treatment Available?
Treatments can generally be divided into three types:
- CPAP/BIPAP - The most frequently used treatment for sleep apnea in this category is nasal continuous positive airway pressure, referred to as nasal CPAP. In this therapy, a prosthetic device consisting of an airflow generator, a flexible hose and a nasal mask is attached to you while you sleep. It uses room air, under pressure, to splint your airway passage open and prevents both snoring and obstruction of airflow in and out of the lungs. To obtain this device, one must sleep in a Sleep Center, under observation in order to determine the amount of pressure necessary to keep the airway freely open during sleep. It is available by prescription following the test.
Nasal CPAP has the following advantages:
- Being able to eliminate both snoring & apnea
- Being effective on almost all patients
- Being available quickly
- Being non-invasive
- Being used in conjunction with weight loss
Nasal CPAP has the following disadvantages:
- Being a nuisance
- Providing symptomatic relief, but not a cure
- Possibly causing nasal dryness or nasal irritation
Other Prosthetic Devices:
- Oral dental appliances. They reposition the upper and lower jaw relationship in an effort to bring the tongue forward and increase the posterior airway space.
- A tongue retaining device. It moves the tongue forward independently and increases the posterior airway space.
- Cervical collars or pillows. They have been reported to relieve sleep apnea, but there are no studies that validate this claim.
- Nasal surgery - This usually involves correction of a deviated septum, repair of a broken nose, reduction of turbinate bones which project from the sidewalls of the nasal passage and/or the removal of nasal polyps. In general, any chronic obstruction of the nasal passage is likely to worsen or induce obstructive sleep apnea.
- Plastic surgery of the palate, uvula, and pharynx - This is referred to as uvulopalatopharyngoplasty. In this procedure, the soft palate and the associated uvula which is the dependent portion of this in the throat, is reduced in size. Any redundant tissue in the posterior pharyngeal wall is removed along with tonsils and/or adenoids.
Recommendations for either nasal or soft palate surgery should be obtained from an Ear-Nose-Throat (ENT) specialist, sometimes referred to as an Otorhinolaryngologist.
Other Surgical Procedures:
Some patients have has their lower jaw surgically relocated, portions of the back of the tongue removed or other types of facial surgery. These surgeries remain experimental and are recommended only in unusual cases.
Tracheostomy: This is a very effective procedure, but is seldom used. An opening from the surface of the trachea is made just below the Adam's apple (larynx). It is closed during the day and opened at night to prevent apnea.
- Weight reduction. Weight loss, in addition to providing other benefits, often reduces the severity of sleep apnea. The only way to determine if weight reduction is beneficial is to be tested for sleep apnea after ideal body weight is achieved.
- Avoidance of alcohol and sleeping aids. These substances reduce the body's ability to arouse when the occlusion occurs. They also increase the likelihood of occlusion by further relaxing the throat muscles and lowering the threshold for airway collapse. Lastly, once the collapse occurs, these sedating compounds make it more difficult to correct the obstruction of the airway. This makes the associated changes both in terms of oxygen loss and carbon dioxide build up more severe and worsen the effects of the sleep apnea.
- Avoidance of extreme fatigue, sleep deprivation and use of caffeine late in the day.