Essay/Term paper: Sleep apnea

Essay, term paper, research paper:  Science

SLEEP APNEA

What is Sleep Apnea?
The Greek word "apnea" literally means "without breath." There are three types of sleep apnea: obstructive, central, and mixed; of the three, Obstructive Sleep Apnea (OSA) is the most common. Despite the difference in the root cause of each type, in all three, 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.
Obstructive sleep apnea is caused by a blockage of the airway, usually when the soft tissue in the rear of the throat collapses and closes during sleep. In central sleep apnea, the airway is not blocked but the brain fails to signal the muscles to breathe. Mixed sleep apnea is a combination of the two. With each apnea event, the brain briefly awakes sleep apnea victims from sleep in order for them to resume breathing, therefore sleep is extremely fragmented and of poor quality.
Sleep apnea is very common and affects more than twelve million Americans. Risk factors include being male, overweight, and over the age of forty, but sleep apnea can strike anyone at any age, even children. Yet still because of the lack of awareness by the public and healthcare professionals, the vast majority remain undiagnosed and therefore untreated, despite the fact that this serious disorder can have significant consequences.
Untreated, sleep apnea can cause high blood pressure and other cardiovascular diseases, memory problems, weight gain, impotency, and headaches. Moreover, untreated sleep apnea may be responsible for job impairment and motor vehicle crashes. Fortunately, sleep apnea can be diagnosed and treated. Several treatment options exist, and research into additional options continues.

How is Sleep Apnea treated?
There is currently no proven drug therapy for sleep apnea. However, there are 4 basic approaches to treatment, which are not mutually exclusive:
1. Modification of circumstances which may be causing sleep apnea or making it worse. This would include weight loss, avoidance of alcohol and sedative drugs, trying to sleep only on your side and stopping smoking. It would also help to improve nasal breathing if this problem exists; sometimes this can be done with some simple medication and occasionally it requires an operation. Finally it is important to avoid sleep deprivation.
2. Use Continuous Positive Airway Pressure (CPAP) in the upper airway to support and hold the airway open. This involves wearing a close fitting mask over the nose, which is attached to a supply of continuously flowing air via a flexible plastic hose from a medical air pump that sits on the floor or bedside table. The flow of air into the mask creates a dilating pressure that is transmitted from the mask through the nose into the upper airway. This positive pressure dilates the upper airway so the breathing is not interrupted. When a sleep apnea patient no longer has obstructed breaths they are able to sleep continuously and hence their quality of sleep improves dramatically. An added benefit is that when the upper airway is dilated sufficiently there shouldn't be any further snoring. The amount of airflow and hence the amount of pressure is determined by your doctor. To date this has been the most successful and well-studied treatment for sleep apnea. This type of treatment almost always works regardless of the underlying cause of the sleep apnea. It is usually well tolerated and does not have any serious side effects. The treatment is not covered by the provincial health care plan, but is covered by some third party insurance companies
3. One of the reasons for the upper airway to become narrowed at night is because the tongue falls posteriorly, especially in the supine position. Since the tongue is attached to mandible this can be a significant problem in people with retrognathia and/or a very large tongue. It is possible to use a dental splint at night that effectively prevents the jaw and tongue from moving back when someone lies down and goes to sleep. There has been less experience with this type of treatment compared to CPAP. Since the upper airway can be narrowed for different reasons, this approach may not work for all patients. The splint may put some strain on the temporal mandibular joint, causing some discomfort. There are now many types of dental splints available but few have been extensively studied so that we are not able to predict the rate or degree of success with this type of treatment yet. It would be important to have follow-up investigations to ensure the sleep apnea is adequately treated if this type of treatment is selected. Patients should consult with dentists or orthodontists that are knowledgeable about sleep apnea.
4. A surgical operation on the back of the throat to remove redundant soft tissue in an attempt to increase the size of the upper airway can be performed. It usually involves removal of the part of the soft palate that hangs down in the back of the throat, as well as the tonsils if present, and other soft tissue if it is felt to be excessive. The operation is referred to as an uvulopalatopharyngoplasty (UPPP) and was initially described as an operation to improve heavy snoring. It is usually quite successful at decreasing the loudness of snoring but is not always successful at improving sleep apnea. There is currently no method that is widely available to predict which patients stand to benefit from this surgery. It is likely going to be less successful for patients with retrognathia. The surgery should not be considered as an option for patients with severe sleep apnea. Like dental appliances there should be some follow-up after surgery to ensure there has been a significant improvement in the severity of the sleep apnea. This surgery can be performed traditionally under general anesthesia in a hospital operating theatre. Short-term results suggest a 50% chance of improvement (defined as a 50% reduction in the AHI). Longer term studies suggest that some patients relapse and their sleep apnea is no longer controlled. Part of the reason for this may be weight gain. More recently this type of surgery is being offered to patients in an outpatient setting using local anesthesia and laser assistance. While this looks like a promising treatment for snoring there are no well-controlled, long-term studies that can demonstrate a role for it in patients suffering from significant sleep apnea. One would expect the results might be similar to the standard UPPP. Currently neither type of operation should be considered as an option for treatment unless patients are unable or unwilling to tolerate CPAP.
Who should be treated?
In most circumstances treatment should be reserved for those patients with particularly troublesome symptoms. What is troublesome for one patient may not be to another so that only general rules can be stated. Sometimes the patient with sleep apnea may not be the best person to decide whether their symptoms are severe or significant. Many patients with sleep apnea have had the problem for several years so they may have lost their proper perception of what a normal night of sleep feels like, or how sleepy during the day they really are.
The most important symptom and indeed what often finally brings people to medical attention is daytime sleepiness. Falling asleep at work or school, an inability to concentrate doing normal tasks, unable to watch TV or to read are all common reasons for treatment. Unrefreshing sleep or just always having to fight the urge to sleep are good reasons to treat this disorder. Sometimes it affects someone's mood and personality. If sleepiness affects the ability of anyone to operate a motor vehicle or power machinery then obviously treatment is mandatory.
A minority of patients have severe sleep apnea (frequent events and/or events long enough to allow a significant drop in the oxygen level). A very few of these people may not have a lot of obvious symptoms (although in general the worse the sleep apnea is at night the more pronounced are the daytime symptoms). Your doctor will take all of this information into consideration as well as your other medical history before recommending therapy and which therapy in particular.

The Evaluation Process
An evaluation at the Sleep Disorders Center begins with an initial consultation with the director of the Center. In many instances, one visit is sufficient for a diagnosis to be made and a treatment plan formulated. For some patients, however, more extensive testing is required. If an all-night sleep study is required, it is performed at our laboratory in The Presbyterian Hospital /Columbia-Presbyterian Medical Center.
The all-night sleep study is a safe and completely painless technique by which physiological functions in sleep are measured. Patients spend one or more nights in a private and comfortable laboratory during which a series of measurements are taken with sophisticated monitoring devices. Patients arrive at the laboratory in the evening and leave the following morning; it is usually not necessary to miss a day of work.
In the course of your night at the sleep laboratory, over 1000 pages of data are collected, along with a complete video-tape record. This data is thoroughly reviewed by our expert staff and when necessary, by additional consultants. A detailed final report is usually ready within one week.