Sleep Study: What to Expect and Why to Get One
I'm Jeff Boyle. I'm originally from Sioux City, Iowa and I started at Avera as a neurologist with an interest in sleep medicine approximately four years ago. Now, I'm medical director of the Brookings Sleep Lab.
What is obstructive sleep apnea?
Obstructive sleep apnea is a condition where a person will stop breathing more than five times per hour is how it can be most simply put. Generally, when people pause their breathing, their oxygen goes low and then they'll wake up. And that just disrupts the sleep and then if they don't wake up, if they just live down in a lower oxygen level, then it's just hard on the body in general but really hard on the heart and the brain which never really stop working. They're always going, they always need blood and oxygen. And so that's why I worry about strokes and heart attacks in these sorts of patients.
What causes sleep apnea?
Sleep apnea generally is caused by one of two problems. One is weight. That there's just a lot of weight around the neck or the back of the throat or over the chest and so the breathing becomes obstructed because of tissue within the oral pharynx, the nose and mouth, that sort of get in the way. The other factor that seems to be involved in sleep apnea is just kind of the anatomy and that's why I think people see that their parents have sleep apnea and then their siblings have sleep apnea and then they wonder if they have it. And that's because of, we look similar and our face is similar to those people around us. And the tongue, and the back of the tongue where that sits in relation to the soft palate and the dangly thing in the back of our throat called the uvula, and that's, I think, where we run into problems. And people have obstruction because that's just the way they're built whether they're heavier set or even thin people can have it.
What are the dangers of untreated sleep apnea?
So, there's different ways that sleep apnea can be dangerous. The first and kind of most evident for people is, that if they're really sleepy during the day and they do something involving driving or working with heavy equipment or if they are monitoring something that is dangerous and they fall asleep during these activities, it can have some really dire consequences. So, the long-term effects of untreated obstructive sleep apnea really manifests as heart disease and brain disease. I worry about strokes and heart attacks. The oxygen needs to supply the heart muscle and if it's low, the heart muscle won't work very well. The brain also will feel that and say, "I need more blood, I need more oxygen. We have things to do to regulate the body," and the brain is always going, even in sleep.
What are the symptoms of sleep apnea?
The first is probably snoring. Somebody that snores loudly, especially that somebody has to, their bed partner, whoever they're sleeping with, has to go in another room, that's a really big red flag. And then if you're not sleeping well, if your oxygen is kind of going low and you're waking up or having disrupted sleep, you'll be excessively sleepy during the day. And then somebody who's just more irritable. If a person gained weight or had some sort of event related to heart disease or a heart attack or lung disease like emphysema or pneumonia, they can have trouble there and then that can make their sleep apnea worse.
How is sleep apnea diagnosed?
The most common test is an overnight polysomnogram or a sleep study. A sleep study has traditionally been done in the hospital or some other hospital-like setting and it's an overnighter test. It's one of the longest diagnostic tests you can have in medicine, I think. So, the sleep study has multiple sensors involving oxygenation of the blood and respiratory effort. If you're trying to breathe and there's no air passing through the nose or mouth, that's indicative of apnea or cessation of breathing. We measure other things, too, like the stages of sleep that people are in. So, if somebody says, "I just don't feel like I'm getting a good night sleep or a deep sleep," we can tell if a person is having a deeper sleep.
How is obstructive sleep apnea treated?
Obstructive sleep apnea is treated using continuous positive airway pressure. It's a lot of words. Just means that if you pressurize the system, then you can keep it open so that that pressure seems to keep the tongue out of the way and the throat open and the soft palate out of the way and so you breathe better. CPAP is used in mild, moderate or severe sleep apnea. It is extremely effective. And I can take a person who's pausing their breathing every 10 seconds and really severe sleep apnea and I can make it so their oxygen level is steady in the nineties all night. It's just amazing with the change you bring with CPAP. Other treatments are available and you'll hear advertisements for oral mandibular advancement devices. And these are sort of like oral retainers or something you can put in your mouth that sort of brings the chin forward and the back of the tongue is attached and that pulls out and that will also open up the airway.
What improvements do patients notice after treatment?
One of the first things that you'll feel once obstructive sleep apnea is treated is just more energy the next day and less fatigue. Certainly, it takes time to get used to CPAP therapy if that's the therapy that you're going through. But many times on the questionnaire that we use after the sleep study, people will say, "The best night, I slept as best as I ever have during the sleep study," because we use the CPAP during that study. Over time, though, with CPAP, that daytime sleepiness really gets better and studies have shown that it really takes months to really reach that plateau where you get to be more normal daytime sleepiness. Over the long run, years and years, there's evidence and theories that the strokes and heart attacks and other vascular events are decreased in people that have treated their obstructive sleep apnea.
Why should patients consider a sleep study at Brookings Health System?
The technicians are doing these sleep labs every night and really very patient and thoughtful in the procedure. The quality of the sleep study is excellent. We have all the data that we need to make an accurate diagnosis and really determine what's going on and how we can help.