Obstructive Sleep Apnea
This is the most common condition for which patients are followed in the Sleep Clinic.
A condition that affects 24 percent of men and 9 percent woman if even mild degrees of the condition are considered, the sleep disruption with this syndrome is characterized by repetitive obstruction of the upper airway throughout the night -generally in the regions behind the base of the tongue. This often results in disturbed sleep quality, reduction and oxygen levels immediately following the events (potentially to a dangerous level), and release of a variety of stress hormones such as adrenalin as well as the resulting inflammatory mediators that can cause damage to many organs, particularly the brain and the heart.
The list of medical conditions-also known as “comorbidities” that have now been directly linked to untreated sleep apnea is growing every year. These include hypertension, coronary artery disease, heart failure, cardiac arrhythmias, pulmonary hypertension,, type 2 diabetes, stroke, glaucoma, dementia…. just to mention the common ones. Additionally the risk of fatal motor vehicle accidents remains markedly elevated in patients with untreated obstructive sleep apnea.
Years ago this condition was felt to occur almost exclusively in patients with obesity, but we now know there are many other causes including a variety of anatomic susceptibilities such as narrow airway, tonsillar size, and position and size of the jaw bone. Many muscular and neurologic conditions can also predispose to this, and even entering menopause by itself can increase the risk for sleep apnea to 24 percent in women, including those with normal body mass index.
The term sleep apnea generally implies the condition known as “obstructive” sleep apnea.(ie 95% of sleep apnea patients have obstructive apnea There is a much less common form of sleep apnea known as “central” sleep apnea which is potentially seen in patients with cardiac or neurologic disease, or a subset of otherwise healthy patients who developed central apnea simply by being placed on standard airway pressure therapy. As opposed to the periods of apnea (or breathing cessation) being explained by the throat closing, central sleep apnea is explained by lack of effort made to take the breath during sleep. (This condition is further described under the description of ASV therapy below.).
Patients who should be evaluated for obstructive sleep apnea are those at risk based on reports of loud snoring and “respiratory pauses” in breathing during their sleep. Obviously these findings are often not noted when patients do not have a regular bed partner. Common symptoms during waking hours including headache in the morning, sleep not being refreshing, poor memory or cognitive function, and sleepiness or fatigue throughout the day despite adequate quantities of sleep. Even in the absence of these symptoms however, the condition should be considered in patients with the comorbidities noted above, as treating the sleep apnea will often improve the success in treating the medical condition/comorbidity. For instance, patients with high blood pressure may often find that successful treatment of sleep apnea will results and reduction or elimination of the need for the blood pressure medicines.
Estimates at this point are still that 80 percent of the population in our country with his condition do not even know they have it. In addition to placing them at risk for these comorbidities, we know that severe apnea can even reduce how long we will live!
The opportunities to diagnose the condition have improved over the past few years with the increased use of home sleep testing, which is generally appropriate in patients who have moderate to high risk for sleep apnea. These studies are generally more convenient for patients as they can be done at home, are not particularly cumbersome, and are more readily covered by insurance. In-lab testing for the condition offers the advantage of excluding other sleep disorders and also to potentially document successful response to therapy such as nasal positive airway pressure (PAP) therapy during the one night study.
In terms of therapy, not all patients with obstructive sleep apnea will require positive airway pressure to maintain an open airway through the night, but the types of nasal devices and mask have tremendously improved in the past few years such that many patients previously unable to except the therapy now find it to be quite acceptable.
Depending on results of the sleep study, there may be other treatment options including positional therapy to avoid sleeping on the back, oral appliance therapy (OAT) to slightly pull forward the jaw during sleep, and of course weight loss should be considered if this is appropriate. In terms of surgical treatment, the traditional approach to surgically remove tissue from the palate and tonsillar region have not proven to be very effective in the long-term. There are however some newer surgical treatments, albeit fairly invasive, that can be considered in patients who cannot tolerate or have adequate response to- the above therapies.