In the UK..New CPAP user, low AHI, but continuing symptoms?

General Discussion on any topic relating to CPAP and/or Sleep Apnea.
markda23
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In the UK..New CPAP user, low AHI, but continuing symptoms?

Post by markda23 » Sat Nov 20, 2021 8:07 am

Hello all,

I am now in day four of CPAP therapy in the UK on a Dreamstation 2 with the Dreamwear nasal mask after being diagnosed with ‘mild’ OSA earlier in the year. During my last sleep study my AHI was 12.5 with average apneas of 24 seconds and the longest at a very long 77.5 seconds. I should also point out that I was a little anxious during my in-home sleep studies, so feel that the results may be underrepresenting my condition, but they are all I have.

Although my OSA is graded as ‘mild’, I beg to differ as it has affected my quality life, and I am concerned about long-term health implications. I have had periods of blood pressure off the scale, blurred vision, night sweats, waking with racing heart, vivid dream, tinnitus, depression, etc, and very fragmented sleep. At best, I probably average about 5-6 hours sleep, often with very early awakenings with heart racing and not able to fall back to sleep. I have tried nasal dilators, wedge pillows, and positional therapy, but with no significant change in my problems. I have therefore decided to give CPAP a go and while my AHI for the first three nights has dropped to 3.6 and is apparently within the target range, I don’t feel much different. While I realise it can take some time for the treatment to work, depending on pressure adjustments, I am somewhat surprised that I am still experiencing much of the same symptoms even though I’m in the target range. My therapist has set the minimum pressure to 4.0 cmH2O, but the machine has progressively gone from 6.0 cmH2O on the first night to 8.0cmH2O last night. So far I have no problems with tolerating the machine or the mask and have worn it all night.

Interestingly, my central and obstructive apneas have been low (a total of 1 and 5 or so per night respectively), but my hypopneas have totalled up to 19. I don’t know my oxygen saturation levels or how to measure them, but I suspect that even though my AHI score is low, some of my hypopnea events are lengthy (although once again, I don’t know how to measure this). I realise there is some software I can use that may help me to get more meaningful data than in the Phillips Dreammapper app or on the device itself, but if someone could help me interpret what I have so far, what the implications are, and why I am still experiencing sleep apnea symptoms with such a low AHI I would be very grateful. Might it be a case that if the pressure on my machine is increased, that the hypopneas improve? Or is this is as good as it gets and I’m just going to have to accept that I am never going to be rid of my symptoms?

For reference, I have nasal resistance, particularly nocturnally, as apparently, I have a moderate septal deviation and not sure about my turbinates. I am seeing an ENT specialist for an examination about this soon, but there does seem to be an issue with my nose, as often I am aware of the nasal cycle when I am in bed with one side appearing to be blocked. To what extent could this be contributing to my problems, and should I get it corrected? Although I understand it won’t necessarily cure my sleep apnea, I guess if I’m breathing easier it may help, and particularly with CPAP.

My apologies if I am asking questions that have been answered before, so feel free to point me in the direction of any useful threads.

Many thanks in advance.

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Pugsy
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Re: In the UK..New CPAP user, low AHI, but continuing symptoms?

Post by Pugsy » Sat Nov 20, 2021 8:30 am

What medications do you take? Names and doses please.

You probably need more minimum pressure to deal with the hyponeas...if they need to be dealt with.
As for software to see the details...that's OSCAR and unfortunately it is not compatible with the DreamStation 2 models.
Respironics has encrypted the data and refuse to share how to de crypt it.

All you have to maybe help you is DreamMapper unless your medical care team will give you detailed information from their software.
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Re: In the UK..New CPAP user, low AHI, but continuing symptoms?

Post by Pugsy » Sat Nov 20, 2021 8:47 am

As long as your sleep is highly fragmented you can't expect to feel much difference.
When sleep is highly fragmented you don't/can't get the nice normal progression into each sleep stage and the needed amount in each sleep stage.

Now figuring out the cause and fixing the fragmented sleep....not easy at all.

Don't assume that sleep apnea is the only cause for fragmented sleep and using cpap will miraculously fix all your problems.
Google "sleep maintenance insomnia causes" and start reading. The list is miles long.

Now you can monitor your oxygen levels during the night if you wish.
You can buy an overnight recording pulse oximeter and easily see what happens with your oxygen levels during the night.
I don't know what it converts to in UK dollars but here in the US they cost somewhere between $50 and $100 depending on how fancy you get. It might be worth it for peace of mind.
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markda23
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Re: In the UK..New CPAP user, low AHI, but continuing symptoms?

Post by markda23 » Sat Nov 20, 2021 9:13 am

Thank you for your reply, Pugsy.

I'm not on any medications.

I'm not sure if my respiratory physician will have much more data than what I'm seeing as we're not using the SD card. I already know how to get into clinician mode, but it doesn't seem to show a whole lot more than what I can see. In any case, I will discuss with my respiratory physician on how I can get more useful data as DreamMapper is pretty basic.

It has taken me almost two years to get the diagnosis of sleep apnea after seeing multiple specialists who all thought it highly unlikely I would have it. Most suspected simple insomnia and I was referred on to a five week Cognitive Behavioural Therapy insomnia (CBTi) course last year which I followed to the letter but it didn't do much, I guess because the main problem was sleep apnea. In addition to counselling, my sleep was restricted, in theory to improve sleep drive, but with the undiagnosed sleep apnea this was not fun. I know sleep apnea and insomnia can go hand in hand so I am expecting that if I can address the OSAH I can then cover the insomnia. In any case, I will have a look at 'sleep maintenance insomnia causes' and I still have all of the materials from the course I did last year. I am pretty good at following the sleep maintenance stuff, but I've just assumed my main problem was the apneas and hypopneas fragmenting my sleep due to low oxygen levels.

I will get an overnight pulse oximeter, thank you for the suggestion. I would like to have that data as my suspicion is my oxygen saturation levels are still low, but I'm happy to be proved wrong. The data will be useful for my next meeting with my respiratory meeting. I will also discuss with her if we should increase my minimum pressure. In any case my night sweats etc are continuing, and I am waking during the dreaming/REM stage, which makes me suspicious, unless it's sleep apnea anxiety related.

Many thanks again.

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Re: In the UK..New CPAP user, low AHI, but continuing symptoms?

Post by Pugsy » Sat Nov 20, 2021 9:42 am

As a sleep maintenance insomnia sufferer myself I can thoroughly understand the desire to want/expect the use of cpap to fix all our problems but it simply doesn't no matter how much we might want it to.

My personal opinion is that often we have more than one single thing that can mess with our sleep and thus how we feel.
Fixing the cpap stuff is fairly easy but figuring out and fixing the other potential causes is a whole different can of worms.
To fix any problem we first have to identify the problem and even then it isn't a slam dunk.
In my case I know the causes and I know how to try to fix the causes but it isn't easy at all.
Chronic arthritic pain is one cause and the other is stress....fixing the pain isn't easy at all but I keep trying and fixing the stress thing is a nightmare challenge.

Have you considered OTC sleep aids or discussed with your doctor RX sleep aids. Sometimes there is a time and place for such meds....at least short term to get us over the hump and get back to some sort of decent sleep habits.

Finally...4 days really is a minute amount of time to expect any sort of decent results even if sleep apnea was the lone cause of your sleep problems. Heck, it took me nearly 4 months for my brain to quit waking me up a gazillion times each night just to warn me about the alien plastered on my face blowing air up my nose.
I know we read about some lucky people who from night one see a marked improvement in sleep quality and how they feel during the day...superwoman/superman change overnight but those people are actually in a small minority. They don't know how lucky they are.

So sometimes we do just have to "give it time" and sometimes it's a long time before we really notice improvements because they are so gradual.
Doesn't mean we don't try to sort out issues while we are "giving it time" though. We have OSA and thus have to use the cpap but it doesn't mean that we don't continue to try to sort out poor sleep quality issues. We can't do more than one thing at a time.

You have been through the CBT thing so I assume intensive education on good sleep hygiene guidelines which is always a starting point.
Try to be patient and not worry so much about not feeling like superman over night. :lol:
Stress itself can and will really mess up our sleep and it's a real bitch to fix. Been there and doing that myself right now.
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markda23
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Re: In the UK..New CPAP user, low AHI, but continuing symptoms?

Post by markda23 » Sat Nov 20, 2021 10:29 am

Thanks again.

I am quite happy to persevere with the CPAP for some time and work with my respiratory physician. In any case the CPAP has reduced the AHI to within the target range, so that's a plus. I just want to get an understanding of what's going on with my oxygen levels because if they are still low then clearly something needs to be adjusted. I know this could take some time until I get on top of this, so I will keep at it. I didn't go into this thinking there would be a quick fix, but I was interested to hear some other views. I appreciate the time you have taken to share yours with me.

As far as I know I don't have any other health issues, although stress can be an issue with me, so I will make sure I'm addressing that in tandem with my CPAP. The last couple of years dealing with an undiagnosed problem has been quite stressful, so I guess it could be partly related to that.

I'm not taking any sleeping aids or medication at the moment. To be fair, I don't have any difficulties in falling asleep... it's the frequent awakenings and not really getting to the restorative REM stage that's the main issue - I just assumed it was related to the sleep apnea. But I guess even when that's addressed by CPAP it can take some time for the mind and body to catch up.

Anyway, I will keep on working at this with my medical team and see where we get to. I am also interested to hear what the ENT guy has to say about my deviated septum and if addressing that is worthwhile. My respiratory physician did mention giving me something to aid sleep, but I think only after I've tried CPAP for some time, which seems reasonable.

All the best.

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Re: In the UK..New CPAP user, low AHI, but continuing symptoms?

Post by Miss Emerita » Sat Nov 20, 2021 12:04 pm

It's good you've adapted quickly to the machine and the mask. Certainly the reduction in your AHI is also a good thing, but at 3+, it still can be a culprit in messing with your sleep architecture.

As Pugsy mentioned, a higher minimum pressure would be a good idea (and would probably be more comfortable for you -- 4 leaves a lot of people feeling air-starved). Do you have flex turned on? That might -- MIGHT -- help with hypopneas.

In your place I would pursue the nose issues with the ENT. Anything that increases the effort of respiration may -- MAY -- degrade the quality of sleep.

There's a lot of experimenting you can do if you're up for it. General guidance is to make one change at a time and stay with it for at least several nights, given how variable sleep can be from one night to the next.
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Re: In the UK..New CPAP user, low AHI, but continuing symptoms?

Post by markda23 » Sun Nov 21, 2021 12:04 am

Thanks very much for your reply.

Last night my AHI has increased again, to 4.1 (and hypopneas up to 20), so seems to be trending up for some reason. I will give this more time given I've only just started, but despite being in the target range I'm still experiencing the same symptoms as when my AHI was 12+, so I guess I now just need to work with my docs to see why that might be.

I just checked my machine and Flex is turned on and set to 3.

I'm seeing my respiratory physician next week so will discuss all of this with her and see what adjustments need to be made, but based on your and Pugsy's feedback it seems that a higher minimum pressure may be the go. Potentially there could something else going on in addition to the sleep apnea too.

I should also be receiving my pulse oximeter tomorrow, so will see what that says. All useful data.

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Re: In the UK..New CPAP user, low AHI, but continuing symptoms?

Post by CyberSpiff » Sun Nov 21, 2021 9:01 am

markda23 wrote:
Sun Nov 21, 2021 12:04 am
Thanks very much for your reply.

Last night my AHI has increased again, to 4.1 (and hypopneas up to 20), so seems to be trending up for some reason. I will give this more time given I've only just started, but despite being in the target range I'm still experiencing the same symptoms as when my AHI was 12+, so I guess I now just need to work with my docs to see why that might be.

I just checked my machine and Flex is turned on and set to 3.

I'm seeing my respiratory physician next week so will discuss all of this with her and see what adjustments need to be made, but based on your and Pugsy's feedback it seems that a higher minimum pressure may be the go. Potentially there could something else going on in addition to the sleep apnea too.

I should also be receiving my pulse oximeter tomorrow, so will see what that says. All useful data.
Hang in there mate, it takes quite a while for some to adjust to CPAP and feel the benefits. I’m only 8+ months in myself and still adjusting though there are some days when I wake up it feels grand. Listen to those experienced on this forum (especially pugsy and miss emerita who responded) and make small adjustments as recommended.

You may be sorely tempted to change a number of parameters or make a big change in one, but as small as a 1 or 2 increment change in pressure may seem it can be a big difference and require readjusting. For myself I went from the default 4-20 no epr to 8-20 epr 3 and it made all the difference.

Give things a chance, listen to those more experienced offering help, and Bob’s your uncle.
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markda23
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Re: In the UK..New CPAP user, low AHI, but continuing symptoms?

Post by markda23 » Sun Nov 21, 2021 12:09 pm

Thanks for the tip and I definitely will take the advice of those more experienced than I. I'm guessing, though, I shouldn't adjust my pressure settings until I've discussed this with my respiratory physician? Knowing what she's like, I don't think she would be very impressed if I did. Not sure how others feel about this.

Since starting CPAP a few days ago, I don't appear to be getting the restorative sleep of days of old, but I will be patient. However, the apneas have significantly reduced and I am perhaps not feeling as bad during the day. And I guess, even if I'm still experiencing much the same symptoms overnight, the fewer the apneas the better, even if the benefits may not be as noticeable right now.

In any case, it seems clear from what everyone has said, that I need to make some small adjustments to my settings. I wasn't aware of the correlation between the 4 setting and feeling air starved, as Miss Emerita mentioned. I have been aware of that sensation when I first put the mask on when going to bed, although I seem to settle into it fairly quickly. But potentially this low setting may be why I am still getting much higher hypopneas than anything else. I also had a bit of a headache today (unusual for me) like I've experienced when I've been at high altitude in Switzerland.

Anyway I'm glad to hear you're having some good days and I hope they keep on coming. All the best, and thanks for taking the time to send me a reply.

CyberSpiff wrote:
Sun Nov 21, 2021 9:01 am

Hang in there mate, it takes quite a while for some to adjust to CPAP and feel the benefits. I’m only 8+ months in myself and still adjusting though there are some days when I wake up it feels grand. Listen to those experienced on this forum (especially pugsy and miss emerita who responded) and make small adjustments as recommended.

You may be sorely tempted to change a number of parameters or make a big change in one, but as small as a 1 or 2 increment change in pressure may seem it can be a big difference and require readjusting. For myself I went from the default 4-20 no epr to 8-20 epr 3 and it made all the difference.

Give things a chance, listen to those more experienced offering help, and Bob’s your uncle.

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Re: In the UK..New CPAP user, low AHI, but continuing symptoms?

Post by Miss Emerita » Sun Nov 21, 2021 12:53 pm

I realize I'm uncertain whether your machine offers C-Flex, A-Flex, or both. If you're using C-Flex, be aware of this little nugget, which I just found:

C-Flex+ Pressure Profile

We see few people benefit from C-Flex at higher levels. It is unlike EPR in that C-Flex is predictive and is apparently the main reason the Philips machines commonly miss expiration time. C-Flex does not follow your breathing, it anticipates it and returns IPAP/CPAP pressure well before expiration is completed. This can make it feel like exhaling is cutoff, but in some individuals, it creates hypopnea by not enabling a full exhale (tidal volume). Higher settings seem to amplify this error.


http://www.apneaboard.com/wiki/index.php/C-Flex

So if you're using C-flex and A-flex is an option, try switching to A-flex. A different experiment would be to turn C-flex down or off.

Different respiratory technicians react differently to patient changes in settings. I think it would make sense to consult here at the outset of your treatment. But if you already have complete access to the flex settings, I wouldn't hesitate to change them. You can explain your reasoning, which might increase the RT's confidence in you.
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Re: In the UK..New CPAP user, low AHI, but continuing symptoms?

Post by markda23 » Sun Nov 21, 2021 1:43 pm

Thanks for this. I have the Dreamstation 2 and all I can see is a 'Flex' option, which is set to 3 and the manual says is the highest level of pressure relief on exhalation. I've not seen any distinction between 'C-Flex' or 'A-Flex'. Do you think I should turn the Flex down a level?

I have changed the minimum pressure setting to 5 which I will trial tonight (and I will ask for forgiveness if the RT ticks me off).

All the best.
Miss Emerita wrote:
Sun Nov 21, 2021 12:53 pm
I realize I'm uncertain whether your machine offers C-Flex, A-Flex, or both. If you're using C-Flex, be aware of this little nugget, which I just found:

C-Flex+ Pressure Profile

We see few people benefit from C-Flex at higher levels. It is unlike EPR in that C-Flex is predictive and is apparently the main reason the Philips machines commonly miss expiration time. C-Flex does not follow your breathing, it anticipates it and returns IPAP/CPAP pressure well before expiration is completed. This can make it feel like exhaling is cutoff, but in some individuals, it creates hypopnea by not enabling a full exhale (tidal volume). Higher settings seem to amplify this error.


http://www.apneaboard.com/wiki/index.php/C-Flex

So if you're using C-flex and A-flex is an option, try switching to A-flex. A different experiment would be to turn C-flex down or off.

Different respiratory technicians react differently to patient changes in settings. I think it would make sense to consult here at the outset of your treatment. But if you already have complete access to the flex settings, I wouldn't hesitate to change them. You can explain your reasoning, which might increase the RT's confidence in you.

markda23
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Re: In the UK..New CPAP user, low AHI, but continuing symptoms?

Post by markda23 » Sun Nov 21, 2021 2:19 pm

I should also point out, in case it's useful, that after I was diagnosed with 'mild' OSA a few months ago my respiratory physician referred me to an orthodontist for a MAD. Following examination and x-ray he advised that in his opinion it would not work because it would not bring my jaw out enough to make a difference. Apparently, in addition to a small recessed jaw, and two molars lost due to bruxism, I also have a malocclusion etc which all seems to contributing to my sleep apnea (although my RT thought I have a 'normal' jaw - medical people contradicting each other is something I'm also getting used to). Funnily enough no dentist has ever mentioned any of this to me in the past. The orthodontist then recommended double jaw surgery followed by braces/invisalign, which completely floored me as it was not was I expecting to hear!

Although I was happy to have the advice, I did some research and am quite apprehensive about such a procedure given the risks so I've decided to get more advice and opinions. I've not ruled it out, but I want to be certain that it will work before going down the path of highly invasive surgery. I went back to my RT and she said it's not a permanent fix and that I could either try CPAP or consider the hyperglossal nerve simulator implant, which I'm not even sure if available in the UK yet. So, although opinion seems to be divided on whether CPAP should be used as treatment for 'mild' sleep apnea, I feel I should give it a go given it is the 'gold standard' treatment and MAD was not advised.

So here I am, and also pleased to have joined my first sleep forum and talking with others dealing with this condition.

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Re: In the UK..New CPAP user, low AHI, but continuing symptoms?

Post by Pugsy » Sun Nov 21, 2021 2:26 pm

Flex...no matter which Flex it might be...isn't going to be doing much at all when the minimum pressures are so low because Flex causes a drop during exhale but it can't ever drop below 4 cm....so even if set at 3...it won't drop at all until the pressure is above 4 cm...so with even the setting of 5 cm...it can only drop to 4...1 cm drop is all a person can get even with setting of 3 until the pressure goes higher.

I suspect that if auto mode is being used that the Flex will be AFlex. CFlex is more for fixed pressure mode.
Not 100% certain though but that has been the way it worked in the past....with the DS2 models though...we have no way to verify default settings or what the machine is actually doing since we can't see detailed data reports.
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Re: In the UK..New CPAP user, low AHI, but continuing symptoms?

Post by rick blaine » Sun Nov 21, 2021 11:34 pm

Hi markda23,

You mention hypoglossal nerve stimulation, and raise the question of its availability in the UK.

HNS is available, and the National Institute for Health and Clinical Excellence (NICE) has issued guidance on it.

Here is what NICE says about the process.

https://www.nice.org.uk/guidance/ipg598 ... mendations

In a nutshell, the method is effective, but not enormously so.

And it has some significant side effects. Doctors should seek permission before they offer it. And make sure patients are fully informed of the risks of treatment.

As to results: several groups were studied, and an analysis of each group was done. And a meta analysis of 200 patients was also done. Patients were studied at +3 months, +6 months. and +12 months.

AHI came down – by about 20. The number of times that O2 saturation fell by more than 4 per cent was significantly reduced. Scores on the Epworth sleepiness scale came down (but not a lot). The percentage of bed partners reporting 'no snoring' or 'soft snoring' increased from 17 pc to 85 pc.

The one thing that stuck out for me – meaning this is what I think is significant – in one group of 46, all of whom had had the implant, the design of the 1-year follow-up was to turn off the machine in 23 patients for a week, and leave it on in the other 23 patients for a week – and compare performance.

And the 'turned-off' group had, on average, 25 additional apneas. Meaning the device, when switched on, was making a difference. But the thing that jumped off the page at me was that the 'leave-it-switched-on' group had, on average, an AHI of 7.2.

And that's with treatment.

For comparison, the target for sleep apnea treatment in the NHS is 5-or-under.

And many members of this forum do everything they can to get their AHI down to 2-or-under.

And both 5-or-under and 2-or-under are eminently do-able with modern APAP equipment.

In my opinion, APAP remains the gold standard. And it has fewer serious side effects than hypoglossal stimulation. See section 5 of the NICE guidance for details of the risks.