What To Do When Soft Cervical Collars Fail

[mawaw1992]

Since I was on the Autosense 10 the last 2 nights, I will wait till the next awakening with the Aircurve. I just started using the Note section to keep with details like awakenings.

[mawaw1992]

I have been trying different pressure and PS settings since my last post. The night before last I had a 4.5 AHI after deducting my SWJ out but felt good yesterday. Then last night I increased IPAP up 1 cm and increased PS from 3 to 4. Last night my AHI was 0.52, which is back to the low numbers I used to always have when I averaged 1.0, back before this problem started, but I don't feel as good this morning. What I don't understand is why did my pressure stay maxed out at the IPAP setting all night long the last 2 nights. I have posted charts from my last 3 nights.

[Sleeprider]

With IPAP max 17 and EPAP min 13 and PS 4 you are using fixed pressure. If you want to see pressure move, you will need a higher IPAP. (13+4=17) Nothing wrong with fixed pressure when it works.

[mawaw1992]

Okay I understand now. Is there any difference in how the machine treats apneas whether it is in CPAP mode, auto with min and max set to the same pressure or on Bipap when the PS makes the IPAP and the EPAP the same such as last night with me? If it looks like a fixed pressure works for me, should I just run it in CPAP mode or leave it on Bipap the way I have it set now?

Thanks,
Mark

[DaveL]

Thanks for posting. Helps me understand positional apnea a little.

DL

[Sleeprider]

Except for advanced ventilators, the positive air pressure devices do not treat apnea as they occur. CPAP and BPAP in a fixed pressure form simply continues to provide pressure regardless of apnea type, duration or frequency.  Auto CPAP and BPAP will increase pressure after the apnea, in accordance with its programming when an obstructive apnea is detected, and depending on the machine when flow limitation, hypopnea or snoring is detected.  The auto machines will generally not respond to CA events or may reduce pressure.

The difference between CPAP and BPAP is blurred with Resmed machines due to EPR in the CPAP which acts like PS in the BPAP.  You do well with bilevel pressure, i.e. when exhale pressure is lower than inhale, so whether the pressure is not changing as in VPAP-S or changes as in Vauto, is a bit of a judgement call. Your setting of 17/13 is not CPAP, but fixed bilevel.  The closest pressure you could get with an Autoset would be minimum pressure 16, maximum pressure 16, EPR full-time at 3 for a pressure of 16/13.  This is what I mean when I say the difference between CPAP and BPAP are blurred.  Enabling the device to increase pressure depends on whether that additional pressure will help to resolve subsequent obstructive events, or if that increased pressure would be uncomfortable and disrupt sleep.  When using auto-pressure our objective is to set the minimum pressure high enough be be effective most of the time, and the maximum to be high enough to treat obstructive events without imposing unnecessary discomfort, aerophagia or other issues. In many cases, it is not necessary to set a maximum because the machine will only increase pressure high enough to resolve obstructive events or flow limitations.

We can really dive down the rabbit hole of how to titrate pressure, with auto vs fixed pressure. Hopefully this explanation helps.

[mawaw1992]

Thanks Sleeprider for the detailed explanation.

[Sleeprider]

To put it briefly:
CPAP: constant positive air pressure with no difference between inhale and exhale (EPR off or minimal I:E transition pressure).
Auto-CPAP: Same as above but pressure increases or decreases according to algorithm to resolve obstruction.
Bilevel: Separate inhale and exhale pressures
Auto Bilevel: Same as above but with auto-adjusting pressure.

So what is a Resmed /CPAP or Autoset with EPR on? It is a bilevel device with pressure support limited to 3-cm and may be fixed or auto-titrating.

[mawaw1992]

I recently recorded myself sleeping and what I noticed was that most of the night I do sleep on my side. On this particular night I had several sets of clusters and the one thing that stood out to me is that the soft cervical collar is working. A few minutes before each cluster, I would roll onto my back and I saw that my chin was up above the collar and never moved. In fact, my whole body was very still. I noticed at the time the first apnea of each cluster would start that my cheeks would fill up with air and I would fiddle with my mask a couple of times. Then after a few minutes I would turn onto to my side and the apneas were over. So, this apparently is not a problem with chin tucking but some sort of problem that has started that involves my airway and maybe my tongue falling further down into my airway. Like I mentioned at the beginning, this problem basically started overnight it seems. With this not being a problem with chin tucking, shouldn't higher air pressure be able to keep the airway open to prevent these clusters?

[Sleeprider]

Higher pressure will stent floppy tissue and keep the airway open. It will not push your tongue out of the way. It's a difficult problem that has been addressed with everything from surgery to mandibular advancement devices, neither of which is very effective. Where the tongue is the primary cause of obstruction a hypoglossal nerve simulator (aka Inspire implant) may be a good solution, or some other tongue restraining device. That said, it's really easy to try increasing pressure to see if it works, and that sounds like to good plan.