False positive for sleep apnea/UARS?

[Bluebuffalo]

Got an in lab sleep study done and my sleep doctor basically said I had sleep apnea and would benefit from an APAP machine. This was based on the fact that I have vivid dreams (due to a medication I take, and they aren’t even vivid I just remember them), snored during the study (I never usually snore, only when I have a blocked nose) and he believes I am choking on my tongue when I enter REM.

ADI = 4.9/hr
RERA = 16.4/hr
RDI = 21.3/hr 

Average sleep latency for 4 naps = 7.1 with 2 under 3 mins

Day of my study I had a pretty bad cold and my nose was completely blocked. When I had my follow up appointment I was quite shocked because the test did not reflect my experience when sleeping at all! I have read through many posts on here and Reddit and I have come to the conclusion that having a blocked nose skewed my results and my doctor took that along with a few things I had previously mentioned and ran with it. He did not listen when I asked him if this was the case and basically shoved me out the door with an APAP prescription. I have never thought I had sleep apnea/UARS I was pursuing testing because I thought I may have narcolepsy based on my symptoms. For context I am 22F not overweight and healthy besides the excessive daytime sleepiness and sleep attacks despite consistent 8+ hours sleep. I have never woken up choking, short of breath or anything like that. I never wake up when during the night however I did wake up several times during the study because I had a cold and could barely breathe through my nose. I am also usually a nose breather and have never really had any problems with my nose/sinuses. The only physical factor that relates to sleep apnea/UARS is the fact that I have a smallish jaw and a wide ish tongue. The only symptom of sleep apnea that I have is the sleepiness. I guess what I’m looking for confirmation on is:

1. Would having a blocked nose have impacted RERA/the overall results?

2. Is it worth getting a second opinion on the results/second study?

Any other thoughts on my situation would be greatly appreciated, I feel like I am stuck in my journey to sort this out and don’t know where to go from here 

[cdplatt]

Do you have a fitness watch or pulse oximeter that might report variations in your O2 saturation while sleeping?  If so, you may be able to determine yourself if a second sleep test is warranted.  Apnea events will cause transient drops in your blood O2 levels.  Drops in blood O2 saturation while you're sleeping are normal, but deep or frequent drops can be a consequence of sleep apnea.  If you're averaging O2 desaturations of more than 3% or 4%, five or more times per hour while sleeping, it's likely you would be diagnosed with sleep apnea in a sleep study.

[Bluebuffalo]

I have an Apple Watch Series 7 which does measure it but I’m not sure how reliable it is.

[Sleeprider]

Nasal congestion would appear as upper airway resistance, aka "flow limitation" on any flow measuring device. During inspiration, any resistance in the upper airway results in a flattening of the peak flow (flow limitation), and this includes nasal limitations. During a sleep study, nasal congestion would have increased "respiratory effort related arousals" (RERA) and potentially AHI and RDI. There is not much doubt your test would have been significantly affected by this problem. The more important measure is whether the fatigue and arousals are common when nasal congestion is not present. There was probably a reason you got a sleep study, and that would still respond to positive air pressure therapy.

[Bluebuffalo]

Thanks for the reply. This is exactly what I was thinking but since I am no expert, I was wanting to confirm this. I got the sleep study because I never wake up feeling rested and could sleep forever. I also tend to fall asleep throughout the day very quickly if not mentally stimulated. I don’t wake up during the night but I did during the study. Would you suggest getting another one done for accuracy? I don’t see how I would benefit from CPAP if I am not actually having many RERAs/hypopneas.

[Bluebuffalo]

Have attached my sleep study below

[Sleeprider]

There is a good possibility that CPAP would help your sleep integrity, and an equal chance it would disrupt your sleep by having to wear a mask, deal with air leaks and other typical problems with adapting to positive pressure. Your respiratory arousals with congestion were about equal to spontaneous arousals, and there your lowest oxygen desaturation was 91% which is not a problem. The test is not very conclusive as to a medical need for CPAP therapy, however you did take a MSLT test where you fell asleep fairly quickly. I think the decision is firmly in your hands whether to try CPAP. If you decide to go with it, we will be here to help in any way possible.

[Apnea23]

Thanks for the reply. This is exactly what I was thinking but since I am no expert, I was wanting to confirm this. I got the sleep study because I never wake up feeling rested and could sleep forever. I also tend to fall asleep throughout the day very quickly if not mentally stimulated. I don’t wake up during the night but I did during the study. Would you suggest getting another one done for accuracy? I don’t see how I would benefit from CPAP if I am not actually having many RERAs/hypopneas.

You say you got the sleep test because you /never/ wake up rested, so we can assume this means even when you're not congested.

You also fall asleep quickly during the day.

If there is no other medical reason you may be tired, and with scores like those, please try the CPAP.

My RDI was less than yours, I had less desaturations and CPAP changed my life.

It's not all about traditional sleep apnea with desaturations. It's about constant respiratory effort and arousals you don't even know about as you switch from nasal to mouth breathing endlessly due to airflow distruptions.

You haven't got the result you wanted, but you've got one that has a very likelihood of solving the issues you're looking to resolve.

What is it you have against the diagnosis of sleep disordered breathing exactly?

If you can obtain a Sunrise Sleep test in your country, that would be a quick and cheap way for you to re-check your respiratory effort. It tracks mandibular movement, so knows when you're in significant respiratory effort.

Based on that you could then decide if you wish to pursue therapy for SBD - UARS, whatever it may be.

[cdplatt]

I'm not sure how the apple watch measures O2 saturation while sleeping. If it just gives you an average for the night, that won't be helpful.  I had one several years ago and don't recall the details.  Fitbit will present a graph, without numbers, that shows the peaks in desaturation during the night and identifies desaturations greater than a certain percent as high variations (orange) and will suggest that frequent high variations might be an indication of a breathing issue that should be followed up with a medical professional.

A pulse oximeter like viatom will provide great detail and is reasonably accurate.  Mine typically shows 7 to 10 O2 saturations >4% per hour and 15 to 16 >3% per hour when I'm not on APAP.  On APAP, it typically reports <1 for both.  That consistency gives me some faith in the accuracy.  It's not an alternative to a sleep study, but is a real good indicator if there is a problem that should be followed up with a sleep study or to give you some faith in the study you already had.

The information on my fitbit is why I purchased the viatom device and the info on the viatom device is why I spoke to my GP about it and had a sleep study.