Does External Noise Affect Sleep Study (PSG) Results

[bv1800]

Last week I had a monitored, overnight sleep study. I was diagnosed with OSA a little over a year ago. I was "morbidly obese" at thge time of initial diagnosis. Since that time, I've lost 20% of my body weight 280 down to 225. I appear to be on of the lucky few where weight loss has a dramatic effect on my OSA.

A year ago, my untreated AHI was 57.4. Wednesdays results were an AHI of 10.4.

The room that I was in had several external factors that made sleep more difficult than your typical in clinic. It sounded like the HVAC vent for the entire hospital passed through the wall by the head of the bed. The noise started with a typewriter clicking type sound, followed by 5-10 minutes of wind tunnel sound (it was so bad that the tech came into the room twice to see if he could find the source). In addition, the room was situated near an area where the staff would congregate to talk and tell jokes. I know for certain that I was awakened at least 10 times, due to external noise.

Question: can these types of external sleep interruptions impact the study results, to the point that they could make the AHI reading increase by 50% or more?

I've spent several hours on google trying to find evidence one way or the other. So far, all that I've found are studies and "expert advise" that external noise must be minimal, to ensure correct study results, but nothing that quantifies impact.

[VictorC]

It would definitely impact the study, but I don't think it would severely impact your AHI. If the noise led to frequent arousals, then your sleep efficiency would be poorer, and it may make it difficult or impossible for you to make it into REM sleep that night. My best guess would be that you might have a few more central apneas if you were frequently transitioning between sleep stages. This would increase your AHI, but probably not nearly as much as 50%. On the other hand, if you didn't make it to REM sleep or didn't spend much time in REM sleep, then your recorded AHI might be lower than it would normally be. Some/many people tend to have more events during REM sleep.

Sorry I know that isn't what you want to hear.

[chunkyfrog]

I totally agree with Victor.

[bv1800]

It would definitely impact the study, but I don't think it would severely impact your AHI. If the noise led to frequent arousals, then your sleep efficiency would be poorer, and it may make it difficult or impossible for you to make it into REM sleep that night. My best guess would be that you might have a few more central apneas if you were frequently transitioning between sleep stages. This would increase your AHI, but probably not nearly as much as 50%. On the other hand, if you didn't make it to REM sleep or didn't spend much time in REM sleep, then your recorded AHI might be lower than it would normally be. Some/many people tend to have more events during REM sleep.

Sorry I know that isn't what you want to hear.

Thanks for the feedback. I actually had similar thoughts on the matter, but I had also convinced myself that the counter argument might be valid. I can also make an argument that titration studies may be more greatly impacted. Either way, I've sent a letter of concern to the sleep center director

I still have 30-35 lb to lose. My results are a positive indication of what might happen at that point.

[sleepy1235]

I think your sleep environment is another example of the shoddiness of sleep medicine.