Teresa Chan-Leveno, M.D. Answers Questions On: Obstructive Sleep Apnea
How common is undiagnosed or misdiagnosed obstructive sleep apnea, and why is it important to recognize and treat it?
Thanks to health education efforts over the past several years, the symptoms of sleep apnea – severe snoring, sleep disruption, and sleepiness during the day – are now better understood by many people.
However, that doesn’t mean that everyone who has the condition is aware of it and receiving appropriate treatment. There is often a disparity between a person’s risk factors for sleep apnea and the severity of the condition if he or she does have it, as well as its impact on that person’s quality of life. So it’s kind of a silent epidemic.
For example, sleep apnea is usually associated with obesity, but there are thin people with sleep apnea, as well. There are severely overweight people who match the phenotype (physical characteristics) that we associate with sleep apnea, but they don't have it. There are people who do have sleep apnea but do not feel excessively tired and still others with fairly mild sleep apnea who are really plagued by their symptoms.
But what’s most important for people to know about sleep apnea is that it is not just about sleep disruption or the annoyance of snoring for your partner; it’s about cardiovascular health. We certainly worry about the safety and productivity of someone who is excessively sleepy. However, people with sleep apnea also have elevated blood pressure and are at increased risk for arrhythmia and sudden death.
How do you diagnose sleep apnea and help patients minimize the health risks of the condition?
It starts, of course, with an awareness of the potential problem. I often weave some of the questions into my initial evaluation of new patients in an informal way. For example, someone may come in for an ear-related problem but is also obese and has a crowded oropharynx. So I may ask him how he sleeps at night and if he feels sleepy during the day. If I am suspicious enough I will refer them for a sleep study either at home or in the sleep lab here on campus.
I consult frequently with my sleep medicine colleagues about patients with suspected or diagnosed sleep apnea. A tool called the “STOP-BANG” questionnaire allows just about anyone to quickly risk-stratify whether someone is at high or low risk for sleep apnea.
Together we are trying to implement this simple questionnaire in various places in the hospital system so that patients can be screened at different interfaces within the hospital and referred if they are at high risk. For example, if someone comes for their pre-operative anesthesia appointment, it is a factor you would like to know both from an anesthesia standpoint and from a general health standpoint.
A lot of people with sleep apnea do come in for help with their snoring, but the snoring alone is not the health problem. So we explain that the snoring is a potential symptom of sleep apnea and that is the thing that is really threatening their health, and they need to be evaluated for these associated risk factors.
Some cases of sleep apnea can be very surprising – and very serious. For example, I have a 20-year-old male patient who is very active and works as a landscaper. But his wife noticed that he turned blue and stopped breathing at night. And his patient history revealed that he had a brother who died in his sleep at the age of 27. Our patient was diagnosed with sleep apnea. Now he has a CPAP (continuous positive airway pressure) device and will receive additional surgical treatment soon.
How do you evaluate whether a patient with obstructive sleep apnea should receive surgery, a CPAP machine, or the newer hypoglossal nerve stimulator?
Traditional surgical procedures for sleep apnea involve removal of tonsils or adenoids, surgical suspension of the tongue, or reconfiguring areas of the jaw to remove the obstruction. However, these procedures are painful, and their success rate is only about 50 percent.
CPAP has always been viewed as the gold standard for sleep apnea because studies show that using the device for at least four hours a night decreases the risk of cardiovascular complications of sleep apnea. So every health insurance company and every conscientious surgeon will tell a patient with sleep apnea to try CPAP first. But some people can’t tolerate CPAP or have a lifestyle reason why it won’t work for them, such as constant travel for work. We also know that sleep apnea is more than just treating numbers. The patient’s AHI (apnea-hypopnea index) gives us a way to understand their severity of disease but does not measure the effects of poor sleep on their quality of life or the strain of constant snoring on their marriage, for example.
The hypoglossal nerve stimulator is an entirely new approach to treating obstructive sleep apnea. It’s a minimally invasive surgical treatment that doesn’t change the anatomy of the mouth or throat area. The device is implanted in the upper right area of the chest, then connected via an electrode to the hypoglossal nerve, which is at the bottom of the chin. You turn it on at night and off in the morning, just like a CPAP machine. It senses your breathing rhythm, and stiffens and protrudes the tongue intermittently to keep your airway open during sleep.
Clinical trials have shown that the patients most likely to benefit from the hypoglossal nerve stimulator have a body-mass index of 32 or less – a little overweight but not morbidly obese. In these patients, we are seeing a success rate between 70 and even 90 percent. So the device represents a real silver lining in the treatment of sleep apnea. UT Southwestern is one of a limited number of U.S. medical centers that now offers the hypoglossal nerve stimulator to eligible patients.