Advice for CPAP pressure and other -- complicated case

[dcg494]

If you have the option to use bilevel, it is clearly more flexible and capable of providing pressure support.  

Sounds crazy, but I got my hands on a dreamstation bipap. A guy right around the corner was selling his for an amazing deal. Hardly used. Lucky!

Well, I tried it last night, and the PS felt great. I'm started low at 4 EPAP and 7 IPAP. The auto- kicked in once to 5 EPAP and 8 IPAP. There was a cluster of Hypopneas that triggered it apparently.

Was thinking I'd go up by 0.5 slowly, keeping the auto on with a small range of +1 on E- and IPAP and a PS range of 3-4 (just to see what the machine wants to do). 

Does this sound ok ? Pretty straightforward I guess, but what about the EPAP increases. Should I stop at EPAP of 5 or 6 ? I think a pretty low pressure is enough to get rid of any OA for me (5-6cm). It's mostly hypopneas and mostly FLs after that. So should i go up max to 5 with EPAP at first, and try inching up with the IPAP (I.e. up with the PS) ? 

I really hope I don't have the same problem as with CPAP -- that I'll hit 9cm pressure and then get aerophagia and more RERAs.

[dcg494]

Yep, looking at last night's data, it looks like EPAP of 4.5 is still really way too low. Was hoping I could keep the EPAP pretty low so I can make it beyond the 9cm IPAP. 

Also interesting to see the CAs increase. Does the PS on Bipap induce CAs more easily ? Not worried about, but curious, never had CAs this high.

Restriction happens on expiration too though, am I right ? 

So tonight I'll increase the EPAP to 5.5 min with IPAP max of 9.5 and PS min of 3 / max of 4.

[jaswilliams]

Increased pressure support can increase CA’s in some people. But also they can reduce as your body gets used to the increased pressure support

[Sleeprider]

Instead of increasing EPAP, I would target the hypopnea and FL by increasing PS min to 4.0. So EPAP min 4.5, EPAP max 7.0, PS min 4.0, PS max 4.5. This will yield an IPAP max of 11.5.

[dcg494]

Thanks Sleeprider! 

Working myself up to your recommendation, at 10cm IPAP max now. Last night, pressure hit the max again for a while at 10 ipap and epap 5.5. And no aerophagia, so that's a big success. With Cpap I couldn't go beyond 9cm. 

But my AHI on bipap is much higher than on cpap. Had 7.5cm pressure, w c-flex of 2 before and AHI was typically around 1 but with a lot of FLs. 

So even though my IPAP is higher with Bipap, my AHI is higher. Maybe I can tolerate a slightly higher epap still also. Do you think I need a higher epap ?

[Sleeprider]

Your obstructive apnea rate is zero. I see nothing to indicate a higher EPAP. It is the PS min that is going to make the difference for you to reduce H and FL. CA is higher, so we want to watch that we don't overstimulate your respiration and make that worse.

[dcg494]

Your obstructive apnea rate is zero. I see nothing to indicate a higher EPAP.  It is the PS min that is going to make the difference for you to reduce H and FL.  CA is higher, so we want to watch that we don't overstimulate your respiration and make that worse.

Hi Sleeprider, some of the hypopneas seem to occur at the middle or end of respiration though, what are your thoughts about that ? 

Just to see, I increased EPAP to 5, but no difference from the night before. I'm now at max IPAP 10.5, with still no problems w aerophagia, so that's one positive. 

Another reason I'd like to go up w the EPAP, is so I can also hopefully have a lower PS at 3-3.5 to get the CAs down. It's mainly the PS that can cause CAs, am I right ? But I also read that CAs can dissappear after a while, after getting used to the PS. Correct ? 

After five nights of bipap experiment, my energy is starting to wane.. feeling like my old, very sleep deprived self again. So huge thanks for your help on this! Hope I can get it right!

[dcg494]

Also, I looked at my last titration study from four years back. Copied below with relevant parts highlighted. I'm just realizing I was titrated at straight cpap pressure! For some reason I always thought I had used c-flex that night. In any case, this doesn't change anything. I may still require less epap than 8, and definitely more ipap than 8. 

But see how the arousal index goes from 17 at 8cm pressure to 49 at 9cm pressure ? What would explain that ?

[dcg494]

Ok, so tried EPAP min 6, IPAP 9, PS 3-4 but it was uncomfortable with some aerophagia again.. Will go back to your suggestion Sleeprider, keep the EPAP lower and try to go up with IPAP min.

One thing, can you help me understand why obstructives should be eliminated by epap and hypopneas/Fls by IPAP ? Quite a few of my breaths in the flow rate graph stop at exhalation, not inhalation.. Can hypopneas be caused by low epap as well ?

[dcg494]

Sleeprider -- finally went up with the PS and IPAP. Tried everything else out first b/c I couldn't seem to find comfortable settings with higher PS and was afraid CAs would go up.

Last night it took me a while but finally fell asleep with PS at 4. (EPAP 5.5 / IPAP 9.5) Best results on bipap so far! 

I cheated a bit with the CAs and took some diamox before sleep. Still surprised to see 0 CAs..

 

Next steps: Will try to get used to this, then finally make the switch to a nasal mask. And maybe I can tolerate PS 4.5 / IPAP 10.