[Diagnosis] AHI going up throughout the months

[thibaulthib]

Hello everyone! 

This is my first thread, even though I have created my account since I have been diagnosed with sleep apnea, in March 2018.

My name is Thibault, French, 28 years old, living in Singapore for the past 4 years.

I never smoked, I am not fat, but I am one of this people who get sleep apnea because of anatomy/physiology issue!
According to my ENT specialist in Singapore, out of the 4 categories of throat/tongue, I am category 4... I.e. the worst, aka small throat and big tongue haha!

My maternal grand mother has been diagnosed 5 years ago, while she was 65 years old. Using ResmedS10.
I have asked my mum to run a sleep study too, 3 months ago, and she is also under CPAP now, using the same than mine, Respironics Dreamstation APAP.

Here is my sleep study results: 12 AHI per hour overall, but 30 AHI per hour during REM sleep. 
No "advised pressure" was given to me in the polysomnographia, hence I am fine tuning the APAP on my own, thanks to Sleepyhead!
The PR is really changing my life, and I haven't been that happy since a loooong time!

However, here is the thing: since I am using the PR, my AHI keep going up. 
I haven't changed anything in my life, and haven't gained any weight either, so I don't quite understand.

Basically, I am making sure to follow the min pressure around 1.5-2.0 cmH20 below the 90% pressure.
Since the 90% pressure keeps increasing, I keep increasing the min pressure too.
I have lately read on the forum that fancy pressure relief features such as Cflex/Aflex/EPR were not advised, so I ended up disabling it too. 
My hose is ok, the Dreamwear mask too, and there is no leak so far.

Some more detail about the settings:
- From the 14th April to the 11th May: pressure min 5.5, and Aflex 1
- From the 12th May to the 18th July: pressure min 5.5, and Aflex 1
- From the 19th July to the 2nd Sept: pressure min 6, and Aflex 1
- From the 3rd Sept: pressure min 6, but Aflex OFF

You can find attached some screenshots about:
- The monthly statistics
- My last night (yesterday 11th sept)
- Example of one night the 6th Sept
- Example of one night in July
- Example of one night in May

Another thing I found out: even though my average AHI was 1.5-2.0 from June to August, and now more around 3.0-4.0, the reading of the events breakdown in Sleepyhead shows that 50% - 75% of the nightly events are actually Obstructive Apneas and Hypopneas.

My question is: why suddenly my AHI is increasing?

If you need any other info to give a diagnosis, don't hesitate to ask me!

Thank you for your help in advance :-)

Thibault

[Walla Walla]

I would try increasing your minimum pressure to 7cm.

[thibaulthib]

I would try increasing your minimum pressure to 7cm.

Thanks Walla Walla! I started at 5, now I am at 6, I am ok to move to 7 of course, but why is my AHI going up, even after I disable the Aflex?

Basically, it even sounds there is a correlation between the 2, as in Aflex was more beneficial to keep my AHI low...

Feeling wise, I am ok with or without Aflex though. So I prefer staying away from it.

[Sleeprider]

Based on your CPAP Statistics chart, your 90% CPAP pressure is over 7-cm H2O. I recommend you change your settings to minimum pressure 7.0, maximum pressure 11.0 and use CFlex or AFlex 1. Your events are predominately hypopnea, and the Philips machine tends to not respond fast enough to prevent these, in fact many times it does not increase pressure at all when these events are spaced by more than a few minutes apart.

In the future when you replace your machine, please consider the Resmed Autoset which is more aggressive in preventing hypopnea, and uses EPR instead of Flex. EPR actually acts as a bilevel that provides separate inhale and exhale pressures with up to 3-cm of difference. This approach is very very effective in dealing with hypopnea.

[thibaulthib]

Based on your CPAP Statistics chart, your 90% CPAP pressure is over 7-cm H2O.  I recommend you change your settings to minimum pressure 7.0, maximum pressure 11.0 and use CFlex or AFlex 1.  Your events are predominately hypopnea, and the Philips machine tends to not respond fast enough to prevent these, in fact many times it does not increase pressure at all when these events are spaced by more than a few minutes apart.

In the future when you replace your machine, please consider the Resmed Autoset which is more aggressive in preventing hypopnea, and uses EPR instead of Flex. EPR actually acts as a bilevel that provides separate inhale and exhale pressures with up to 3-cm of difference.  This approach is very very effective in dealing with hypopnea.

Thank you so much Sleeprider! Very grateful about what you do for the community here!

Actually, I got proposed by the ENT specialist the Dreamstation, hence I went for it because I was really in bad shape: spent one full week having panic attacks every day, hallucinations, depersonalisation disorder, etc. just because of sleep deprivation!

So when the sleep study results came, I bought the PR straight. Next CPAP, I will definitely go for Resmed.

Question: Between Cflex or AFlex 1, is there one better than the other, or we can consider they are equivalent?

Thank you!

Thibault

[Gideon]

PR's Flex algorithm seems to "fight" some users causing difficulties and at times forcing the pressure higher to "handle" issues that were caused by the flex.  If you are not fighting the flex feel free to use it.  

In your case I think it may actually be because you stopped using flex.  Rather than chase numbers from where they are at right now (your current chart says a min of 7 should work for you), let's go a trial with flex(?) and min(5) as you had it in May when your numbers were better.  The only issue I have with reverting is that many users, myself included, have trouble with lower pressures (4-6) in that they feel they are struggling to breathe (see the below question). In this case I would go for the 6-7 min and add the flex back in.

You are in a range where your numbers are good so we need to always ask the most important question,   How do you feel?  Did you notice any difference when you stopped using flex?    


Fred

[thibaulthib]

PR's Flex algorithm seems to "fight" some users causing difficulties and at times forcing the pressure higher to "handle" issues that were caused by the flex.  If you are not fighting the flex feel free to use it.  

In your case I think it may actually be because you stopped using flex.  Rather than chase numbers from where they are at right now (your current chart says a min of 7 should work for you), let's go a trial with flex(?) and min(5) as you had it in May when your numbers were better.  The only issue I have with reverting is that many users, myself included, have trouble with lower pressures (4-6) in that they feel they are struggling to breathe (see the below question). In this case I would go for the 6-7 min and add the flex back in.

You are in a range where your numbers are good so we need to always ask the most important question,   How do you feel?  Did you notice any difference when you stopped using flex?    


Fred

Thanks Fred!

Since I stopped using AFlex 1, it took me 2 nights to get used to it, so I guess that is why my AHI was high. But now, it has been exactly 1 week and my AHI is still high.
Today, my AHI is almost 5 and I feel tired. I don't feel as good as when my AHI is 2.

Another question: Can an higher minimum pressure cause more hypopneas ? That is what I start wondering myself...

Thibault

[Sleeprider]

I prefer Cflex which only does the pressure relief for exhale. The best advise is try both and see what works best for you.

[arc0509]

I am also 28. Was diagnosed in October 2016 and using Dreamstation Auto. A couple of months ago I too had episodes of continuously rising AHI. Where normally I have it around 5, I was getting upto even 15 on few nights. Tried playing with settings but the results were all erratic. Not even the cervical collar worked. Fed up i just left it as it is.

However, as the weather changed and the peak heat of summer season passed, my AHI started dropping. I cannot sleep in AC whole night as it doesn't suit me. So I used to wake up multiple times in the night to adjust the ac temperature. But as the rainy season arrived and summers were over, my AHI started stabilizing and is mostly near 4-5 now.

I looked up on the net and found one clinical study too which came to a conclusion hat AHI increases at higher temperature. So firstly, check whether the ambient temperature is the issue.

Secondly as sleeprider pointed out, Dreamstation is really slow in responding to events. Yesterday only i was looking at the Sleepyhead and saw that the flow rate of the machine rarely increased in response to Hypopneas. I am still playing with settings to get the best AHI ratings.

What i would suggest you is to increase your pressure a bit. 5-7 seems really low for a dreamstation machine as per my experience. Although, people find even this pressure optimum. But your first step should be progressively increasing the pressure and check your readings. I am supposing you are using dreamwear nasal mask which i find to be very comfortable and leaks are rarely an issue.

My mother and elder brother too are on CPAP. I have severe sleep apnea mainly due to a short neck as per the doctor. So i guess our cases are really similar.


That being said, I haven't had much success in getting AHI under the range of 4-5. Maybe thats due to the inherent limiation because of our short necks. Nevertheless, keep increasing pressure and try to use C-flex and avoid A-flex.  Only trial and error can get you the right results.

I will be watching this thread since maybe i can get some useful info from your experience.

Also, I suspect my nasal blockage as being one of the reasons in this rising AHI. Does your nose also blocks on lying down?

[arc0509]

Higher minimimum pressure causes central apnea i guess.