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Re: No Answers Yet For Problems With ASV
Posted: Thu Jul 14, 2011 7:35 pm
by Guest
NotMuffy wrote: The body needs to build up CO2 and then a regular breathing pattern resumes. This phenomenon occurs following an "arousal" - a sleep disturbance that causes a deep breath, or "sigh" followed by a compensatory pause.
............
Those need to be left alone.
Should machine-induced centrals also be left alone?
Exactly how does a machine-induced central develop?
Re: No Answers Yet For Problems With ASV
Posted: Thu Jul 14, 2011 8:19 pm
by dsm
Guest wrote:NotMuffy wrote: The body needs to build up CO2 and then a regular breathing pattern resumes. This phenomenon occurs following an "arousal" - a sleep disturbance that causes a deep breath, or "sigh" followed by a compensatory pause.
............
Those need to be left alone.
Should machine-induced centrals also be left alone?
Exactly how does a machine-induced central develop?
Guest, Here is but one scenario (as I understand it) for that situation (in very simple terms) ...
If your xPAP machine is set incorrectly (cpap/auto with pressure too high for what is needed, bipap with badly set risetime and/or epap/ipap gap) and an event (e.g. sleep arousal) results in you breathing faster/deeper
than you would normally then the result stemming from the machine's intervention can cause your breathing to drop your blood CO2 level to below your normal blood CO2 threshold, in which case your respiratory sensing (chemoreceptors) will signal to your breathing to slow or pause until the sensing system sees your blood CO2 level back in range.
I believe there are several factors that can affect the extent/depth of the reaction.
Should machine induced centrals be responded to - of course but that may involve changing the machine's set up. If the machine is causing central dysfunction, it needs attention.
Cheers
DSM
Re: No Answers Yet For Problems With ASV
Posted: Thu Jul 14, 2011 9:20 pm
by Paper_Nanny
NotMuffy wrote:Anyway, you only breathe when you need to (insert 47 exceptions here later).
I thought two more exceptions were added last year, bringing the total to 49, with the exception of the Czech Republic, where it is still only 35.
NotMuffy wrote:This phenomenon occurs following an "arousal" - a sleep disturbance that causes a deep breath, or "sigh" followed by a compensatory pause.
Are arousals the only time this occurs?
NotMuffy wrote:Anyway, cross out all those centrals in the waveforms and recalculate your AHI.
I will say 6.1. It is my final answer.
Deborah
Re: No Answers Yet For Problems With ASV
Posted: Thu Jul 14, 2011 11:17 pm
by StillAnotherGuess
Paper_Nanny wrote:
I will say 6.1. It is my final answer.
Which may or may not make you smarter than a fifth grader, so lets say the real answer is 5. That would put you in a unique position of being a solution in search of a problem. The problem would still appear to be what is the problem?
Re: No Answers Yet For Problems With ASV
Posted: Fri Jul 15, 2011 12:23 am
by Paper_Nanny
StillAnotherGuess wrote:Which may or may not make you smarter than a fifth grader, so lets say the real answer is 5. That would put you in a unique position of being a solution in search of a problem. The problem would still appear to be what is the problem?
Oh, Silly Guess, that by no means puts me in a unique position. It puts me in exactly the same position as all human beings. We are all solutions seeking a problem. We all have our own special blends of talents and gifts. Part of the human condition is a search to find ways to use those for the benefit of others, while at the same time, finding those whose talents and gifts will be of benefit to us.
It is with that in mind that I ponder your most recent posts to this thread. I am trying to understand why you feel drawn to me and my situation. Why do you feel the need to say these things to me? Are you here to give help me or are you looking for me to give something to you? Or looking for something from someone else here? I ponder, but come to no conclusions. Ponder and ponder... Ponder and wander, meander and contemplate, knit and purl, pearl and pear as I go from here to there.
As for being smarter than a fifth grader, the way I look at it is I don't have to be smarter because I'm bigger. And I am allowed to cuss and they're not.
Deborah
Re: No Answers Yet For Problems With ASV
Posted: Fri Jul 15, 2011 12:40 am
by ozij
Deborah, your posts are giving me so much pleasure, and I don't mean just because of your incredible wit. It's the way you embroider the tapestry of humanity that has me awed and touched and chuckling all at once.
A thread full of wonder -- and like the best threads on this forum, teaching us about people at the same time as it teaches us about machines and breathing.
Thank you for continuing it.
Re: No Answers Yet For Problems With ASV
Posted: Fri Jul 15, 2011 12:48 am
by rested gal
ozij wrote:
Deborah, your posts are giving me so much pleasure, and I don't mean just because of your incredible wit. It's the way you embroider the tapestry of humanity that has me awed and touched and chuckling all at once.
A thread full of wonder -- and like the best threads on this forum, teaching us about people at the same time as it teaches us about machines and breathing.
Thank you for continuing it.
You're absolutely right, ozij... on all counts about Deborah ~~~ and her thread.
Re: No Answers Yet For Problems With ASV
Posted: Fri Jul 15, 2011 1:50 am
by Mr Bill
NotMuffy wrote:If that time span was 10 seconds or more, that was a central apnea (not really, you'd need to be asleep, but pretend).
Anyway, you only breathe when you need to (insert 47 exceptions here later). The response to the large breath was normal. The body needs to build up CO2 and then a regular breathing pattern resumes. This phenomenon occurs following an "arousal" - a sleep disturbance that causes a deep breath, or "sigh" followed by a compensatory pause. On the waveforms, it looks like this:
Those need to be left alone. I would imagine if you tried to attack it with an ASV, the already low pCO2 would be driven lower no matter how aggressive the attack is, and a run of chain centrals could occur (you would probably need to have some of that "increased chemoresponsiveness" for that to really perpetuate. Normal chemoresponsiveness is like a shock absorber. Hit a bump and you only bounce once).
Anyway, cross out all those centrals in the waveforms and recalculate your AHI.
I thought those sighs could be discounted! Cool. IIRC somebody noted that the Respironics ASV algorithm never intervenes on the first missed or abnormal breath but progressively intervenes on the ones following.
I see many pressure pulses marked with the red block but also pressure pulses with no red blocks. So it appears to me that the marked red pulses are marking pulses used to check for CA. Whereas the other unmarked pulses are interventions to keep things moving along.
What about the data around 5:37 AM and 5:43 AM? There are shallower but faster breaths and there is a pattern of pressure pulses that rises to a peak and then falls off repeated several times in the middle of those breaths. Is this an example of where pressure was used to intervene and keep all the breaths the same magnitude? In that case is this evidence that the ASV is doing something beneficial right there that simple CPAP or BIPAP would not accomplish?
Re: No Answers Yet For Problems With ASV
Posted: Fri Jul 15, 2011 4:46 am
by NotMuffy
Paper_Nanny wrote:NotMuffy wrote:This phenomenon occurs following an "arousal" - a sleep disturbance that causes a deep breath, or "sigh" followed by a compensatory pause.
Are arousals the only time this occurs?
As demonstrated, you can obviously do this in wake. The inability to discern actual sleep is a huge stumbling block in attempting to analyze single-channel data.
In addition, your frequency of awakenings (16 in the titration study, probably representative of your baseline) may also generate a lot of stuff that should be exluded (wake events are
not scored during NPSG. Single waveform automated analysis obviously does not have that ability).
Re: No Answers Yet For Problems With ASV
Posted: Fri Jul 15, 2011 9:48 am
by StillAnotherGuess
Paper_Nanny wrote:[. I am trying to understand why you feel drawn to me and my situation. Why do you feel the need to say these things to me? Are you here to give help me or are you looking for me to give something to you? Or looking for something from someone else here?
I'm drawn to you because I'm trying to understand what your situation is, currently, that you have not articulated very well. I also enjoy your humor and your wit. Your original problem of PTB is mitigated. You have a small residual AHI issue. CPAP will not cure fatigue, MS, or pills. What is your current CPAP problem?
Re: No Answers Yet For Problems With ASV
Posted: Fri Jul 15, 2011 11:05 am
by Paper_Nanny
Mr Bill wrote:In that case is this evidence that the ASV is doing something beneficial right there that simple CPAP or BIPAP would not accomplish?
Is my machine doing things like an ASV? I thought with the current settings, it was acting strictly as a BiPAP would. Settings: BPM=0, Pres Max=12, EPAP Max= 12, EPAP Min=8, PS Max= 4, PS Min=0.
Or is it still doing something ASVish because I wasn't able to set PS min= 4?
Deborah
Re: No Answers Yet For Problems With ASV
Posted: Fri Jul 15, 2011 11:13 am
by Paper_Nanny
NotMuffy wrote:Paper_Nanny wrote:NotMuffy wrote:This phenomenon occurs following an "arousal" - a sleep disturbance that causes a deep breath, or "sigh" followed by a compensatory pause.
Are arousals the only time this occurs?
As demonstrated, you can obviously do this in wake.
In sleep, are there reasons not associated with arousals that one would sigh?
Given that we cannot tell from my wave form data whether or not my sighs were post- arousal, I am asking more for the purpose of satisfying a curiosity rather than looking for practically applicable information.
Deborah
Re: No Answers Yet For Problems With ASV
Posted: Fri Jul 15, 2011 12:29 pm
by StillAnotherGuess
Paper_Nanny wrote:Is my machine doing things like an ASV?
Yes. It is not only doing things like an ASV. It is currently set up in ASV mode. PS Max > 0 = ASV Mode.
Paper_Nanny wrote:I thought with the current settings, it was acting strictly as a BiPAP would.
To act as a BiPAP, you would need to set PS Min > 0.
Paper_Nanny wrote:Settings: BPM=0, Pres Max=12, EPAP Max= 12, EPAP Min=8, PS Max= 4, PS Min=0.
Typical ASV settings
Paper_Nanny wrote:Or is it still doing something ASVish because I wasn't able to set PS min= 4?
No. Currently PS Min=0 is sitting on your EPAP value. Think CPAP.
I'm not your enemy.
Re: No Answers Yet For Problems With ASV
Posted: Fri Jul 15, 2011 1:17 pm
by StillAnotherGuess
To state it more correctly, your machine is currently set up in CPAP mode with ASV assist.
Re: No Answers Yet For Problems With ASV
Posted: Fri Jul 15, 2011 1:34 pm
by StillAnotherGuess
Which brings to mind that ASV assist may not be doing you any favors, as Bob and NM previously stated, so you could try setting PS Max=0.