Average AHI vs deep sleep stage AHI question

[BezDuh]

Hello guys, 

After many years of sleep issues I was recently diagnosed with sleep apnea. I didn't know that this disease existed and that mechanical obstruction could cause such issues. I'm a 43 years old male from Sofia, Bulgaria. It turns out sleep doctors in Bulgaria or at least those that I have visited in Sofia are not there to provide any help to sleep apnea sufferers, taking into account that throughout all those years they just prescribed me only sedatives medicine that didn’t work to me and they didn't rule out the apnea disease by just advising me to have a self test with a device at home.
Recently I did my self test and it showed that I have relatively low AHI which is around 6. I don't know how it should feel like when one has AHI 6 or 60 but my experience with AHI 6 is that I feel terrible. I hardly do my job at work and because of that I estimate my quality of life as too low and because of that I suspect that my average AHI index does not reflect exactly how I actually feel.

Attached are pictures of the sleep report made using ResMed ApneaLink:

drive.google.com/file/d/1m-5HwBULmTxcDTtFse8EJ-kiz4GytKKg/view?usp=sharing
drive.google.com/file/d/1m2HG_pYnz5ljUenYyGZ7LVPbLFNsYGHE/view?usp=sharing

According to that report my only explanation for my discrepancy of how I feel and what the device reports is that my index is the average AHI for all the hours in bed. During REM stages the device doesn’t register any apneas, but in the other deep sleep stages I have apneas which if calculated only for that part of the stage the value reaches AHI 50 or 60. I suppose that REM stages don’t cause the body to refresh enough and being said that then my question here is if that is the case does that mean that I have severe AHI 50+ index or this is a wrong assumption and I should take into account only the average index of 6 (the average for the whole night)? Do other apnea sufferers with medium and severe indexes register apneas during the REM stages and thus contributing to the average index?

I truly appreciate your help and bear with me, English is not my native language.

Thank you!

[BoxcarPete]

My in-lab polysomnography showed a REM AHI of 25, nREM AHI of 0, and overall AHI 5.8 for the whole night. REM sleep is somewhat difficult to detect with a high degree of confidence even for the full array of sensors, so at home sleep tests are much less likely to get the sleep stages correct.

[CPAPfriend]

Everyone is different, and so different patients will subjectively respond differently to the same AHI / RDI / etc. With regards to symptoms of sleepiness, cognitive impairment, brain fog, etc. we know that REM sleep is more important.

It's common for AHI / RDI to be higher during REM, because REM sleep results in muscle paralysis which can further contribute to collapse of the airway.

[BezDuh]

As a follow up to my thread, it might be possible that I have central apnea. All of my reports show that I have consistently a certain amount of central apneas roughly 50% of all the events. I was ignoring it all the time because if a doctor notices it then the advice was that those might be erroneous events or false positives. I have discussed those findings with @CPAPfriend and he confirms that CA events seem to be real. I switched over to fixed pressure a few days ago using the median value from the previous auto mode sessions and if someone is interested could take a look at the reports before (auto mode) and today (constant pressure):

auto mode:
https://drive.google.com/file/d/1FeaqYvFLBTzGqt_UvBCAMbVtWptVYlmP/view?usp=sharing
fixed mode:
https://drive.google.com/file/d/1FgjdX0jy_tHyzgCaLF_IEDAqjs3_t9l-/view?usp=sharing

What I'm noticing is that some of the CAs are preceded by small leak and that's why all the time I assumed this might be due to the leak, which might be caused by changing sides.
Recently I wake up consistently around 3am and after that the sleep is quite weak without any deep phases at all till the rest of the night. My explanation is that I have a low level of arousals and in auto mode the pressure changes are waking me up.
Being said that, what are my options for treating CA? Should I move to BPAP first and see how it goes or because of that low level of arousal or should I go with an ASV machine?

I appreciate you help!

[CPAPfriend]

I took a look at your data, and it does look like fixed pressure makes for a less eventful night, and I would be interested in seeing what a few more nights staying on those settings will show.

It is possible that those small leaks could be negatively contributing somehow to your disordered breathing, though they are quite small. Let's not write them off for now.

I personally believe ASV could be warranted here. Your CAI is relatively low, but that doesn't account for all the irregular and potentially-responsive-to-ASV breathing that we see between CAs. At any rate, looking at your sleep study, there is very clearly something going on and so it's just a matter of figuring out what exactly that is. Your ODI is quite high, the SpO2 profile looks terrible given your health circumstances, and you have many pulse spikes throughout the night.

I hope someone else with some knowledge can weigh in here for the sake of discussion.