Robert was clearly anxious about spending a night in a sleep lab, since he never liked sleeping in hotel rooms. He always followed a specific bedtime routine, and was concerned that he would not be able to sleep at all in the sleep lab. Due to the very high likelihood of having obstructive sleep apnea, and with a history of leg movements, I recommended an in-lab study.
An in-lab comprehensive sleep study is considered the “gold standard” for sleep apnea testing. A number of different wires are attached to your body to measure the following: brain waves, nose and mouth channels for airflow, chin and leg movements, oxygen levels, snoring microphone, and chest and stomach belts to detect movement.
Because it’s so comprehensive, it can also be somewhat intrusive. Being hooked up from head to toe (actually ankle) can prevent you from getting a good night’s sleep. Here are 7 reasons why an in-lab study is not the most ideal way of measuring your sleep quality:
1. It’s not your normal sleep environment.
It’s bad enough traveling and having to sleep in a hotel room with an unfamiliar bed and surroundings. How about adding wires to your scalp, eyes, chin, chest finger and legs? Many of you have asked me, “How can you expect me to sleep in a strange room with all those wires and with someone watching me?
The good news is that despite people’s fears, the vast majority of people are able to sleep long enough to be able to calculate a sleep apnea score, or the apnea-hypopnea index (AHI).
2. Not your normal sleep times.
No matter how well you try go to bed at a set time, it’s almost impossible to time it just right, especially if you’re in a new environment. Many patients have told me that they were expected to go to sleep much later or much earlier than their normal sleep times. This is like trying to sleep in a different time zone. Make sure you call ahead to see approximately when you’ll be able to go to sleep.
3. All wired up and tethered.
Having all those wires on your entire body can definitely make it uncomfortable for you to sleep. It can also tether you to some degree, preventing you from rolling side to side.
4. Not your normal sleep position.
Having wires attached to your body will also prevent you from sleeping in your normal sleep position. Many labs will tell you to sleep on your back. For some of you, this can be a form of torture, since you won’t be able to sleep at all on your back.
5. Not your usual pillow.
Most likely, you’ll forget to bring your favorite pillow. Many people are very particular about their pillows. It’s also important to realize that a pillow can significantly affect your head position and your airway size.
6. Stuffy nose from nasal cannula.
In-lab and home sleep studies all use a plastic nasal channel with two prongs that fit inside your nostrils. This measures nasal airflow. But in some cases, having something in your nose can create more vacuum forces that causes your nostrils to cave in more, which can keep waking you up. One exception to this situation is the Itamar WatchPAT unit, which doesn’t use a nasal cannula.
7. Overkill for most routine OSA.
For most run-of-the-mill cases of obstructive sleep apnea, a home study should be more than adequate. There are very specific situations where an in-lab study may be needed, such as in patients with neuralgic conditions, heart failure, or patients with special needs. However, for the vast majority of patients with sleep apnea, in-lab studies can be overkill.
Despite all these limitations, it’s the best that we currently have. Home testing is getting better, and there may come a time when most routine testing for sleep apnea can be handled through home testing, with the medically complicated patients reserved for in-lab studies. With better technology and perhaps with advances in smartphone features, screening for sleep apnea will definitely undergo rapid changes in the near future.
In case you’re wondering, Robert was found not to have any significant sleep apnea, but did have lots of leg movements (called periodic limb movements). Upon further questioning, he reported that he had to shake his legs and walk around just before bedtime, which was consistent with Restless Leg Syndrome (Willis-Ekbom disease). He also had low iron levels. After being given iron supplements for 3 months, his sleep quality improved.
In my next post, I will reveal the 7 Reasons Why I Don’t Like Home Sleep Studies.
If you agree of disagree with any of my 7 points, I’d like to know. Please enter your comments below.