Why doesn't APAP respond to apneas?

[Snoredog]

Good starting point.

1) One value we need is Bev's typical BPM without there being any machine influencing factors such as PS or backup rate or auto-adjustment rate.
We could get that by setting BPM=off

I think that is all you can conclude from results so far. I think when you set BPM=Off there is no backup mode or it is disabled. Since she has periods of central dysregulation is that a good thing to do?

BPM can be easily gotten off the LCD in Monitor mode, it will give you the average of last 6 breaths, I suspect a BPM avg is still there. Same for Rise time and Inspiration time. BPM on her first night on the SV avg'd 14.6, if protocol is followed you use spontaneous -2 (i.e. 14.6-2=12.6). Inspiration time ranges from .5 to 3 seconds. Machine will never let IT get over 3 seconds or it will cycle.

2) Set the machine in CPAP mode as already suggested and stick with the CMs set to 14 based on it delivering consistenly better results - then we
are looking at Bev's baseline reaction using the SV's better data reporting capability

Actually last night was set to CPAP=14 for EPAP. Compared to Aflex, it was the same starting pressure but limited to 18 cm Max. That bumping into IPAP Max is what resulted in HI being seen. Since we started IPAP Min also at 14 cm, it was CPAP +SV mode.

3) Don't use PS yet until we have a night or two on this same machine, in CPAP mode & no timed mode

She doesn't appear to do well with PS either that she cannot tolerate the rapid movement of IPAP working pressure. Wonder how she would do with 18/14 fixed.

Add to this what we think we should be seeing in the data for Bev based on what we know of her weight height etc:
a) Peak Average Volume
b) Tidal Flow
c) breathing rate

Agree on wht meds Bev should be on

DSM

Bev indicated she is 5' 7" and from what I can tell ideal weight since her PSG shows a BMI=20, it don't get no better than that.

AVAPS Chart guide says:

Set the target tidal volume, either to 110% of the displayed patient
tidal volume when ventilated on S/T mode or to 8 ml/kg of ideal weight.
Adjust depending on patient tolerance and clinical outcomes.
Target Vte may be set from 200 ml to 1500 ml.

Since there is NO target tidal volume on this machine, we have to compare where she should be for her given height to the Encore avg.

If I look up her height on the chart of 67" she should be at 530ml tidal volume, at 395 she is a bit low yet. But that is under SV control, not backup settings. Again, I think the IPAP Max limited the machine's response in correcting that, but it doesn't have anywhere you can input height to know what the target volume should be. It is my understanding it only targets peak inspiration volume so to get tidal up you have to get Peak up.

Ramp: If she is to continue with the SV, I think setting up a Ramp for her should help make it easier for her to fall asleep. Ramp only impacts EPAP setting, any IPAP Min will remain as IPAP pressure until Ramp expires.

Giving her a Ramp from 9 to 14 over 30 minutes might help her a lot in falling asleep.

[OutaSync]

I'm back from the wedding. I had already set up my machine for test no.1 before I left so I could just fall into bed. I'm still going with those numbers. I'm not ready to give up, yet. SWS is right. The whole thing started when I realized that my APAP was letting me have an average of 36.6 second apneas without doing anything to stop them.

I set a ramp of 9 for 25 minutes. I haven't used a ramp since my first week on APAP. I never felt like I was getting enough air with ramp.

Snoredog, I just checked my LCD and there is nothing there. I'll have to remember to check it in the morning before I take the card out.

I'm out,
Bev

[Banned]

The AHI on CPAP 14.0 cmH2O is 1.4.
The AHI on CPAP 14.0 cmH2O is 1.4.
The AHI on CPAP 14.0 cmH2O is 1.4.
The AHI on CPAP 14.0 cmH2O is 1.4.
The AHI on CPAP 14.0 cmH2O is 1.4.
The AHI on CPAP 14.0 cmH2O is 1.4.
The AHI on CPAP 14.0 cmH2O is 1.4.
The AHI on CPAP 14.0 cmH2O is 1.4.

Conclusion

I think you guys are trying to shove a square peg into a round hole.

I have to admit I never read this thread until now. So, another-one bit the dust and bought a SV? My only question is (aside from the great AHI numbers on CPAP) why clip IPAP Max at 18? Sounds to me like a good candidate for AVAPS. I wouldn't feel so alone..

Banned

[-SWS]

Banned, the wide swings of PS initially made Bev sleep poorly and wake up with both aerophagia and headaches. We don't know yet if she's well suited for any BiLevel, let alone varying SV levels. We don't know yet if she can slowly acclimate to BiLevel or SV for that matter.

My suggestion to Bev is to first baseline BPM and volumes, while noting significant variability if any. Then to introduce small deltas. Baselining before introducing experimental deltas is pretty much standard procedure in science. Not here, though. In science you typically try to get starting values that are controlled---that means establishing reference values that have not yet been skewed by the very experimental deltas you propose to introduce and study. Then you try to introduce those experimental deltas in a controlled and individually measured manner. Again, not here!

Here, we have started introducing many experimental deltas all at once. And we are also willing to take those randomly influenced BPM and volume measurements, and treat them as if they are known good starting/baseline values for comparison.

Welcome to the too-many-chefs-in-a-kitchen thread!

[Banned]

My suggestion to Bev is to first baseline BPM and volumes.

Welcome to the too-many-chefs-in-a-kitchen thread!

Thanks for the welcome. I'm all for experimentation. Having AHI < 1 with the Adapt SV, I got AVAPS to raise my normal 500VT to an equally normal 650VT and am struggling to get the AHI of 14 down to single digits. I don't understand trying to baseline Bev's BPM. Isn't her baseline BPM 16, or there 'bouts from her previous report? Isn't her VT 369, or there 'bouts, also baselined from that report?

Banned

[-SWS]

I don't understand trying to baseline Bev's BPM. Isn't her baseline BPM 15, 16, or there 'bouts from her previous report? Isn't her VT also baselined from that report?

A baseline should ideally be free of the effects you intend to introduce and measure (BiLevel/SV). Her previous reports contain potentially skewed values since Bev reported having slept and felt so adversely with autoSV.

By contrast, stable pulmonary values (unskewed by the pressure effects of the BiLevel/SV that we propose to introduce) can be readily collected in this case: using CPAP @ 14 cm. I'm fairly certain I'm the only one in this thread who sees it that way.

Banned, please take my chef's hat... This transaction is a zero-sum game.

[ozij]

Banned,
This thread started out with Bev reporting excellent AHI on a auto at 14-17,

• feeling miserable
  having long 36 scecond apneas

The question was - and is - what is going here. Nobody knows Bev's breathing parameters under those conditions.
She has an SV that can be used to track her baseline under either straight 14, or a 14/17 b--level. This machine can be used to find out how Bev breathes - under these baseline condition.

Data about what is going on, in the basline condition, or as close to it as possible will help everyone understand where Bev is at now.

SAG - do you consider Bev's time spent in apnea (according to the APAP) important? Could those long apneas be a result of Bev holding her breath because of pain?

By contrast, stable pulmonary values (unskewed by the pressure effects of BiLevel you propose to introduce) can be readily collected in this case: using CPAP @ 14 cm. I'm fairly certain I'm the only one on this message board who sees it that wayI'm fairly certain I'm the only one on this message board who sees it that way.

No you're not, I said it was an excellent idea, and considering the her present cpap AHI is 1.4, I would do this proposed data gathering (fixed cpap 14) for a week.

That's not an expensive doorstop, Bev. That's an expensive data gathering machine.

And I would follow SAG's information about controling the pain. I think there is consensus that you can't be expected to sleep well at night and then feel fresh and chipper during the day when you're in constant pain.

O.

[-SWS]

No you're not, I said it was an excellent idea, and considering the her present cpap AHI is 1.4, I would do this proposed data gathering (fixed cpap 14) for a week.

I forgot. Thanks for the reminder, though.

That's not an expensive doorstop, Bev. That's an expensive data gathering machine.

True... but also humorous!

And I would follow SAG's information about controling the pain. I think there is consensus that you can't be expected to sleep well at night and then feel fresh and chipper during the day when you're in constant pain.

Important IMHO.

Could those long apneas be a result of Bev holding her breath because of pain?

Presumably the arousals and awakenings are attributable to unresolved pain as well. But the possibility of either central or obstructive apneas that are pain or other (non-blood-gas) stimuli related is an interesting area of consideration. Also potentially related in etiology: the cases of CompSA/CSDB where the obstructive component elevates in response to various machine pressures. Sympathetic/parasympathetic involvement? I'm thinking excessive C.A.P. related. I'm also thinking Bev's wild apnea spikes to non-LL leaks may very well be one such case.


Thanks for weighing in, ozij.

[StillAnotherGuest]

SAG - do you consider Bev's time spent in apnea (according to the APAP) important? Could those long apneas be a result of Bev holding her breath because of pain?

I think it's very unlikely to see long obstructive apneas (they should have been terminated by arousal much sooner) out of the clear blue sky (they're only singletons. I believe the obstructive pattern is more clearly represented in the 10/23 - 10/24 download and appear as a salvo - Bev, how long are those?) on pressures that should have been pretty much therapeutic (so it's more likely they're artifact or central phenomena of some sort, like post- or inter-arousal centrals, wake something or other, or plain ol' artifact).

However, this SAG Crystal Ball Reading should be given some scientific basis after review of NPSG, where extremely long events were observed:





SAG

[dsm]

SWS,

I though my response to your post was me conceding to your baseline argument ? - I just added in the bit about use the SV to get Bev's BPM without the machines PS & rate mechanisms influencing it (bpm=off).

DSM

[-SWS]

Doug, thanks!

I think it's very unlikely to see long obstructive apneas (they should have been terminated by arousal much sooner... it's more likely they're artifact or central phenomena of some sort, like post- or inter-arousal centrals, wake something or other, or plain ol' artifact).

Thanks for that as well, SAG. Just an unqualified opinion that treating most of the above long-apnea scenarios with pressure probably won't fix the underlying issue(s) behind Bev's poor daytime symptoms (which are still undetermined).

However, this SAG Crystal Ball Reading should be given some scientific basis after review of NPSG, where extremely long events were observed

Look forward to that. Thanks in advance.

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Just a quick line of thought about sleeping with pain while using PAP (which applies positive pressure against the LES). Despite using Lyrica I slept the entire night with some "background" trigeminal pain (i.e. constant low level chronic pain). Naturally I'm feeling unrefreshed. But interestingly I experienced more aerophagia than usual. So I'm wondering if the body's vagal response to pain might trigger LES dyscontrol. More likely the aerophagia is just a gastrointestinal response to what I ate for our later-than-usual dinner last night. I'll have to watch for a possible link between chronic pain during sleep and aerophagia---hinting at a possible pain/vagal link regarding LES dyscontrol and vagal afferent pressure stimulation. If I spot a link I'll be sure to mention it in this thread. Otherwise it was just last night's poor dinner choice.

[Hawthorne]

I am certainly no expert and can't really follow this thread with any intelligence.

I do however, have Rheumatoid Arthritis and Sleep Apnea.

Ozij has raised the possibility that Bev is holding her breathe because of pain and that is causing apneas and her feeling of non restorative sleep. This I understand! At the moment, my arthritis pain is under good control so my apnea therapy is doing a good job for me.

When my arthritis is flaring(not under control for various reasons - stress, a need for medication review and possibly change) my sleep therapy doesn't do much to make me feel rested in the morning.

From my limited experience, I would say that Bev should look into this possibility that night time pain may be a real factor. I often do not wake up in the night feeling the pain but I sure know I have not had a good night, painwise, when I get up in the morning. It shows in the way I feel and in my data.

[ozij]

Thanks for adding your perspective, Hawthorne.

O.

[OutaSync]

This from last night



I woke up with a terrible headache that continues, (and no, it's not a hangover, I don't drink) aerophagia was the same.

Bev

[Banned]

Could the headache be from the cocktail of anti-depressants, pain-meds, and sleeping pills?

Banned