[Symptoms] Events when transitioning to sleep, then shallow breaths?

[userexec]

Hello! I was recently diagnosed with mild sleep apnea (AHI 10) and got a DreamStation Auto. Have been using it for about 3 weeks, then the other day happened across someone who wanted to get rid of a lightly used System One BiPAP autoSV Advanced for $200 . So naturally, bought that as well.

Anyway, both machines seem to work great for me and take my AHI down to much better levels. The ASV seems to clear up most of the hypopnea and RERA events that the Auto CPAP wasn't getting. But I've noticed something unusual when using either machine and was wondering if some more experienced folks could chime in on what I might be looking at.

Whenever I'm falling asleep, I get a ton of events during the transition. I basically crash into sleep with all the grace of a cupboard falling off the wall if the event charts and the ASV's timed breath carpet bombing during that period is to be believed. Then once I'm asleep, the breaths just look awfully fast and shallow to me. It looks like a pretty consistent 4 seconds per breath or so. When I'm awake I take around 10 seconds per breath and am a rather diaphragmatic breather, so I'm wondering if the transition is just so rocky because my breathing styles between wakefulness and sleep are so different.

Either way, I'm curious how common these things are, bot the cascade of event flags while falling asleep, and the fast, shallow breathing while asleep.

Also, anyone else who's experienced Auto machines going nuts trying to correct your breathing while you're trying to transition to sleep, any tricks for getting over that hump would be great. Wishing there was some advanced ramp setting where it could stay fixed pressure and then kick in the algorithms after I've made it to sleep--one can dream!

Thanks in advance for any insight you can provide!

   

   

   

[userexec]

Oh, I should note, the Auto CPAP screenshots there are actually in CPAP mode with just a fixed pressure because I was getting so annoyed with trying to fall asleep with the auto stuff going crazy during the transition to sleep. I have actually had it set to an automatic range, but the two issues noted are the same regardless. I figured it would be most illustrative to show a fixed pressure example so we can rule out the algorithms as causing those transition events

[Sleeprider]

Sleep onset central apnea and hypopnea are common, and yours is more prominent due to very high respiratory flow and volume as you mask up and prepare to sleep. Your machines measure that high baseline and as the flow and volume drops to your normal sleep levels, the reduction in flow meet the criteria for flagging events and triggering pressure support on the SV which is trying to maintain the tidal volume from the preceding 90 second. Eventually you hit your normal sleep rhythm and volume which is around 14 bpm and 380 mL. Do yourself a favor and take a minute or two to relax and let your respiration settle, rather than just jumping into bed and slamming on the mask.

Your CPAP results show persistent flow limits (flattening of inspiration wave) which gives rise to RERA and H events. The SV corrects those, but would do better wit an additional 1 cm of EPAP min pressure and a minimum PS of 3. The SV shows you are spontaneously triggering 100% of breaths, so the increase on PS is mainly leveling Tidal volume. I think your ideal machine would be a Resmed Aircurve 10 Vauto, but this is working fine. Bilevel pressure is needed for the flow limits, RERA and hypopnea, and the SV is probably overkill, but it effectively treats those problem with a cost of being more disruptive than auto bilevel. Some ASV users will blow back at the machine to reset that you are in control.

[userexec]

That is extremely helpful info and makes total sense. The mask going on too early is such a "oh why didn't I think of that?" moment--I can't expect the machines to predict the future. Thank you so much!

[userexec]

Just wanted to let you know that that advice totally eliminated the event flag tumble into sleep! Just gone! Did a meditation session in bed and only put on the mask after I took off the headphones, and was able to get right into the pattern no problem.

The higher pressure support will likely take a few days to get used to I'd imagine. I changed to EPAP 7-10 and PS 4-7, but I might walk that down to the minimum PS 3 you recommended and see how that works tonight. I didn't feel like I had a lot of timed breaths, but apparently I did.

Thanks again for the awesome advice!

   

   

   

[userexec]

There we go    Many fewer timed breaths after a night of getting used to it and a pressure drop to EPAP 6-9, PS 3-6. Now to just work on staying asleep longer, which has always been an issue even before machines came into the picture.

   

[Sleeprider]

Glad to see that worked out. The machine just doesn't know how to respond when it is confronted with tidal volumes near 1000 and the respiration rapidly falls under 400, so it tries to maintain that higher rate. This looks great, and your situation may help others experiencing the same.

You can see the periodic increases in EPAP that is part of the SV auto algorithm. Like all things Philips, it "trials" 1.5 cm pressure increases over 2-minute periods throughout the night. You can kill that by making minimum and maximum EPAP the same value or not using SV auto with fixed EPAP. It doesn't look like you need higher EPAP anyway, and this will further stabilize pressures.

[userexec]

Thank you again so much for the incredibly insightful advice. I should also post this screenshot of the zoomed in version of last night showing the improvement of that flow limitation. Still very new at this, but I think that looks like exactly what we're shooting for with those flattened tops gone!

   

[Sleeprider]

Looks much better, but let's compare the Resmed mask pressure, and you will see why this is such a favored therapy for comfort.  The inspiratory pressure support continues until exhale begins, while your Philips often quits and falls back to EPAP before inhale is complete.

[userexec]

Ah ya that looks way, way more natural. I can imagine the comfort benefits of having it ramp smoothly and fall off like that. I really was not a fan of A-Flex on the DreamStation because of it cutting me off before I was done inhaling. Either the ASV (and I assume, by extension, the other Philips BiPAP devices) is better about that, or I'm just getting more used to it. I definitely notice it cutting out pressure support a few milliseconds before I was done sometimes, though.

I'll be on the prowl for an Aircurve. Doubt I'll find as outrageous of a deal as I did on this ASV, but when the right one comes along I'll grab that and do a comparison.