This is the second of a series of six posts on obstructive sleep apnea. Read part one HERE.
I usually see two types of obstructive sleep apnea (OSA) patients. The first is someone who was referred by their primary care doctor or came to see me on their own with a suspicion of OSA. The other is a patient who has already been diagnosed and treated by a sleep medicine doctor who is referred to me for possible surgery. I will stick to the first group for the purposes of this post.
The average OSA patient first shows up in my office usually at the urging of their spouse or bed partner. Their spouse generally complains of loud snoring with frequent pauses in breathing or choking/gasping spells. The patient is usually unaware of all this (because he’s at least partway asleep), but instead complains of excessive tiredness during the day. Other common complaints are morning headaches, problems concentrating or remembering things, low energy, depression, and other mental health issues.
I will also have patients fill out an Epworth sleepiness scale, which is a series of questions that act as a screening tool for OSA. You can take the survey yourself HERE.
After taking a complete history, I will examine the patient. The first important data point is their weight and body mass index (BMI). Obese patients are much more likely to have OSA. Then, I will perform a comprehensive ear, nose, and throat exam. I focus on the inside of the nose and mouth and look for any problems that cause narrowing of the airway, such as a deviated nasal septum or large tonsils.
I will then perform a flexible endoscopy of the nose and throat. This is a quick procedure that allows me to see all the way to the back of the nose and then look down at the back of the throat and the voice box. The endoscope is a thin camera that is shaped like a long spaghetti noodle. This procedure allows me to see all of the upper airway and determine where all of the narrow areas are located. I use a topical decongestant and numbing spray in the nose beforehand to make the procedure more comfortable. It takes about 30 seconds and is very well tolerated by almost everyone.
Here is a video of a flexible endoscopy of the nose and throat done by an ENT doctor in Virginia. He focuses more on the voice box and vocal cords in this video, but I look at all these same areas in patients with possible sleep apnea.
At this point, if I have a suspicion the patient has OSA based on my history and exam, I will send them to get a sleep study (fancy medical name = polysomnogram).
The sleep study is ultimately what determines whether a patient has OSA or not. During a sleep study, the patient is monitored all night and has his breathing, oxygen levels, brain waves, stages of sleep, and heart rhythms recorded. Traditionally, sleep studies have been done in sleep labs, but more and more often, patients are being sent home with a portable machine for the study.
The sleep study provides a lot of information, but for my purposes, there are 2 numbers that are important. The first is called the Apnea-Hypopnea Index (AHI) which is the average number of times per hour that the patient has events where they stop or slow down breathing. An AHI of less than 5 is normal, 5-15 is mild OSA, 16-30 is moderate OSA, and greater than 30 is severe OSA. The highest AHI I’ve ever seen was 140!
The second number that I look at is the patient’s lowest oxygen level during the night. A normal oxygen level is over 90%. If the patient is dropping below 90%, I know that they are having a problem getting enough air. The lowest oxygen saturation I have ever seen was 37%.
After the sleep study, I will see the patient back to discuss treatment options.
The next post in the series will talk about non-surgical treatment of OSA.