THE PROBLEM OF OBSTRUCTIVE SLEEP APNEA
Sleep apnea syndrome is caused by frequent reversible obstructions of the upper airway causing interruption of sleep. These obstructions have two effects on the person who has them. First, symptoms of disturbed sleep result from the interruptions. Treatment should improve the quality of sleep and reduce symptoms. Second, the obstructive events can cause long-term consequences. High blood pressure, heart attacks, strokes, diabetes and elevated cholesterol levels have all been associated with increased frequency of obstructive events. Treatment should also be able to prevent these problems. In fact, treatment of apnea, when it successfully eliminates the obstructive events, has been shown to achieve both of these goals.
How do we treat the individuals with throat collapse and those with excessive body weight as they work to lose weight? The three traditional categories of treatment are medications, surgeries and medical devices. The discussion of the miscellaneous causes is beyond the scope of this discussion.
CAUSES OF OBSTRUCTIVE SLEEP APNEA SYNDROME
- Excessive Body Weight 25%
- Miscellaneous causes
- (Throat abnormalities, metabolic abnormalities, etc.) <5%
- Non-specific throat collapse 70%
Under ‘Obstructive Sleep Apnea, What is It?’ the causes of sleep apnea were reviewed. Excessive body weight is seen in over half the patients diagnosed with sleep apnea syndrome. There is evidence that with weight loss the sleep apnea of about half of the overweight patients will disappear. Weight loss is strongly encouraged in all overweight individuals. It is the treatment most likely to result in a long-term resolution of the problem.
Positive Airway Pressure
The two types of medical devices used to treat obstructive sleep apnea are positive airway pressure and dental appliances. It has been known for over twenty years that obstructive sleep apnea can be corrected by positive airway pressure. When the air pressure in the throat is raised to slightly higher than the local atmospheric pressure, the throat does not collapse. When the throat does not collapse, the obstructive sleep apnea syndrome is corrected. The symptoms resolve and the risk of long-term complications are markedly reduced. With consistent use of positive airway pressure, the symptoms related to poor sleep are usually resolved and the long-term risk for elevated blood pressure, diabetes, elevated cholesterol, heart attack and stroke returns to that of the population without sleep apnea. Positive airway pressure is the primary therapy for all levels of obstructive sleep apnea. Positive airway pressure is a simple concept.
Dental appliances work by holding the lower jaw (mandible) forward. This holds the back of the tongue away from the back of the throat and at the same time pulls the palate forward. The appliances are effective in reducing obstructions, especially in individuals with lesser problems and may be of value in patients who suffer from milder levels of sleep apnea syndrome. Dental appliances are considered when therapy with positive airway pressure fails. If the obstructive events are low in number and the person’s symptoms are mild, a dental appliance may be effective.
In the vast majority of patients with sleep apnea syndrome, throat collapse during sleep is the cause of the obstructive events. It appears that both the size and the shape of the throat, along with the relaxation of the pharyngeal muscle tone, determine if the throat will stay open or collapse during sleep. There are no known medications that increase the size of the throat or increase the muscle tone of the pharyngeal muscles. At present, there are no medications to prevent and treat sleep apnea.
If abnormalities are discovered in the upper airway, then surgery may play a major role in the correction of obstructive sleep apnea. For example, removing enlarged tonsils that are obstructing the airway will often correct the apnea in those individuals.
For individuals who have no anatomic abnormalities, surgeries have been designed to treat their obstructive sleep apnea. All the procedures are designed to increase the size of the throat, either at the level of the palate or at the base of the tongue. A number of procedures have been described for both locations. The procedures have some general features in common. They are not used as the first treatment for obstructive sleep apnea. Generally, when used they are successful less than 50% of the time, are quite painful for two to three weeks afterward and have some associated long-term complications. There is a third type of surgery which is a major surgical procedure designed to enlarge the space behind both the palate and the tongue. In this procedure, both the upper jaw (maxilla) and lower jaw (mandible) are moved forward. Maxillo-mandible advancement is a technically demanding major surgical procedure which is only effective 70% of the time. Because of the low success rates, surgical therapies for obstructive sleep apnea are used when traditional therapy with positive airway pressure fails.
Provent Sleep Apnea Therapy is a disposable, nightly-use nasal device placed just inside the nostrils and held securely in place with hypoallergenic adhesive. Provent uses a proprietary MicroValve design that creates pressure when you exhale to keep your airway open.
MEASUREMENT OF SUCCESS
Obstructive sleep apnea is treated to both eliminate symptoms and to eliminate the obstructive events. Symptoms that result from the problem should be resolved or improved. The obstructive events need to be eliminated. Correcting the AHI to a normal level ensures the reduction of long-term adverse events to a normal level. Any treatment chosen should achieve both goals. The success of treatment should be measured both by how you feel and what happens to the obstructive episodes while you sleep. How you feel will be clear to you, but the obstructive episodes will not always go away when symptoms improve after treatment.
To ensure that the obstructive events have disappeared, retesting is indicated after weight loss, after surgery to enlarge the airspace, and after dental appliances are properly fitted and used.
If the treatment is positive airway pressure, a sleep test while wearing the pressure mask is usually performed prior to beginning treatment. This ensures that the events are resolved and determines the appropriate pressure for home therapy. If not retested at the sleep center, a home test should be used to ensure that the events are resolved.