Higher Pressure,More Apneas?

[DoriC]

I know increasing pressure can sometimes induce centrals but would increasing pressure to achieve a lower AHI instead cause more apneas? Under what circumstances could that occur? Thanks.

[mars]

Hi Dori

I guess that if it was taking too long to increase the pressure needed to prevent an apnea, a higher starting point would help.
But that higher starting point may increase centrals - only the results will tell.

I am currently having to increase my starting point and highest point to respond to what is now happening.

And probably some experimentation will be needed.

Others here will certainly have a better idea than me, but that is my best shot

cheers

Mars

[bayourest]

I seem to be the odd one whose apneas increase with pressure increases.
I am pretty new at all of this and I have no idea why it happens. I was titratred in my sleep study at 10. I have experimented with increasing my pressure in a fairly methodical manner to see if I could achieve lower A.I.and it seems that no matter what I do (cpap, apap, EPR on or off etc) my apneas increase when I raise the pressure. so, who knows why??

[jbn3boys]

I'm on straight bipap, so no auto adjusting. I have found with my most recent pressure increase, my AHI (OA, CA, H) has gone up. I have NO idea why.

BUT, I'm feeling a tad bit better. So I'm not complaining.

Only confused!

Guess that doesn't help you much, huh Dori!?!?

[chrisp]

Hello,
I'm not really sure how to explain this so here goes. I believe that EPR increases at different pressure levels is this correct. Did you increase your pressure? As you exhale the EPR kicks in and causes a momentary drop in pressure, Then you inhale. This MAY be interpreted as a blockage or flow limitation in SOME people. It may also cause them.

As you use your apap and gain experience you will notice that your best settings MAY be at or 1 below and 1 above your titrated setting. Or more. This may be more effective and comfortable because you will not get awakened by pressure changes when the unit needs to react because the change will be very subtle.

My titrated setting is 15. My minium set is 14 high is 16. When I used to have a wide range when I was a newbie I had all sorts of problems. Also, lets say I had it set at 10-16. It would show my 95% as 13 even tho I knew it was 15. The Hypopnias would go WAY up. Now they're gone. It may only take a lower pressure to eliminate Apneas but much higher to eliminate the Hypopneas.

Disclaimer. I don't have a resperonics unit and only know about it from the limited literature that I have read and I may be mixing up some info from other machines.

Good Luck,

Cheers,

[DoriC]

My titrated setting is 15. When I used to have a wide range when I was a newbie I had all sorts of problems. Also, lets say I had it set at 10-16. It would show my 95% as 13 even tho I knew it was 15. The Hypopnias would go WAY up. Now they're gone. It may only take a lower pressure to eliminate Apneas but much higher to eliminate the Hypopneas.

Disclaimer. I don't have a resperonics unit and only know about it from the limited literature that I have read and I may be mixing up some info from other machines.

Good Luck,

Cheers,

I'm confused about that comment I've bolded. I would think that for 95% of the night you slept at 13 or LESS and for only the remaining 5% of the night you may have slept at a higher pressure. So are you just going by your titration pressure to know it should be 15? What pressure did your data say you slept at for most of the night?

[bayourest]

thanks for your explanation chrisp.
I am now running apap at 10-11 to see how that goes. My scores shot up at cpap 11.6 and apap 8-16 so what you say kind of makes sense to me intuitively. I am considering trying some apap 9-11 or even 9-10.6 or perhaps titrating down a little from 10 sometime. I figure I've got a lot of time to work on this!! thanks

[KatieW]

I know increasing pressure can sometimes induce centrals but would increasing pressure to achieve a lower AHI instead cause more apneas? Under what circumstances could that occur? Thanks.

Dori, Mike's data doesn't differentiate between obstructive versus central apneas, right? And he's on cpap of 12 cm h20, according to your signature box. What is the breakdown of AHI--AI/HI?

In my own therapy, I have observed that I got more Centrals when on apap with a range of 4-5, eg. 8-13. It may be that they were from arousals from the changing pressure. It didn't happen so much on a tighter range, eg. 11-12, or on straight cpap of 12. My obstructive apnea index stays about the same, which is .2 or .3 (very little).

So, if you don't know if his apneas are obstructive or central, then raising the pressure might make his AHI better--if he needs more pressure to keep the airway open. Or, the higher pressure could make it worse--if it disturbs his sleep, and he has "centrals", which I put in quotation marks, because they may not be "real" centrals, just arousals.

Also, if his AHI is higher, is it statistically significant? Or, more importantly, does he feel more tired, unrested, etc. And another thought, could his medications be affecting his AHI?

Hugs to you, and hope that I was a little helpful.

[chrisp]

Doric,
What we must realise is that things are constantly changing. Allergy season, heating season, A/C season, Duck season . Its not a set it and forget it thing. I'll check mine weekly or so when I feel something has changed to check the AHI. I am usually having problems with the Hypopnea index tho. That takes a few more CMWC to control . I guess I have flappy tonsils or something

I recently had a sleep study after 9 years. I was self titrated at 14. Kept the setting at 14-16.5. After the study they came up with 15. So my APAP data was right on. I do notice that anything below 14 will greatly increase my Hypopneas from 1.5 to 5 or more so I don't go there even tho the apneas are only .5 . The machines reacting to these hypopneas wakes me and I get very little sleep anyway. So 14-16.5 is my happy place for now. IT WILL CHANGE with the seasons. Sometimes lower. Hopefully

[DoriC]

There was no mention of centrals in his sleep study so I don't think that's a problem and I don't think I've ever observed that when I was "hovering" over him. Most of his events are "frank" apneas, appearing out of the blue, not related to snores or leaks and usually occurring in the early morning hrs. His AI is always higher than his HI(he has very few HIs). I'm trying to reverse those numbers but that's the way it's always been.