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+--- Thread: BiPAP Pressure for Possible UARS (/Thread-BiPAP-Pressure-for-Possible-UARS)
RE: BiPAP Pressure for Possible UARS - Macka - 04-09-2024
For the lean, I mean in both graphs. After the trigger, the breath tends to develop a shape similar to the pressure wave. You can see overall the breaths are shaped just like the pressure wave, which in a Resmed charts I see, seems is largely this right leaning spikey pressure wave.
On that second chart, I think it is more straight up and down because the breathing is, at this stage in the night, just more in line with the machine algorithm and timing. The trigger from zero into inhale is very sharp, look at how the backwards L shape on the mask pressure at epap into ipap are nearly exactly the same between breath and pressure wave. Overall each breath is near the same shape as each pressure wave.
On my own chart above, the rounded inhales are largely because of the pressure wave shape being fuller and somewhat rounded. Last night I increased the inhale ramp to the steepest on level 1. All my breaths showed a left lean and some of them had a late collapse in the shape, as all the air came early which triggered exhalation sooner as well. Tonight I will go to the opposite end with ramp 3 and I bet I see all the breaths lean to the right and some early collapse. As you play around with the pressure delivery you are shaping the breaths. You are limited however by the machines inherent programming.
I have just read through your journey helping out your dad. He is lucky to have you nutting all this out with him, and is definitely in a good place with his therapy considering the problems you have overcome sofar.
I do believe the idea of the airway becoming destabilized at end of expiration not only for apneas, but inspiration as well, holds a lot of merit. I believe it can be seen in your dads charts while the machine is holding down at epap 9 all that time, destabilization is creeping in by end of exhale, extending right through zero and into early inhalation. Large pressure support is then needed to try reverse it. I have heard knowledgeable sleep specialists talk about it being very hard to reverse a concentric collapse like in difficult UARS cases. Using large pressure support against weakened respiratory system or small physiological size is going to cause larger fluctuation in breath stability.
If you ever have a chance to trial a machine which can deliver an eepap pressure, would be worth a try. As it is, you only have the option to raise epap to try stabilize the airway a little more before the inhalation trigger and possibly reduce the pressure support as a result of the stabilization. You may have already tried this? Are you at your best place right now having exhausted all adjustments on that machine?
RE: BiPAP Pressure for Possible UARS - SingleH - 04-09-2024
His waveform was shocking when he was on CPAP, he had been on CPAP for 3 years by that point and I didnt know it was that because his F&P unit wasnt supported on Oscar, it was only last year that I noticed support was available and then to my horror saw how bad it was. Sleeprider steered me in the right direction to get him on Bipap asap.
I didnt notice your observation about the pressure wave and flow rate graph looking identifical until you pointed that out. As you suggest perhaps another sign of synchronicity and hence why the flow limits disappear. It is only when this second waveform occurs that his flow limits completely vanish. He can be on the same pressures or higher but when that waveform is not present he will continue with steady flow limits. Of course this could also be a partial collapse so your comment about raising EPAP I believe is a very valid one.
I have found the more I raise EPAP the more he gets longer periods of the better waveform, suggesting the airway is remaining more stable. It had been difficult to increase EPAP because he also needed a decent level of PS to stablise his waveform and address flow limits. I'm at the point though where I will have to sacrifice PS to do so, as with the current settings its border line with leaks for him.
This is why I like the features of the Lumis 150 where you can have PS sacrificed when EPAP raises, rather than the fixed range of PS on the Vauto that pushes his IPAP too high and in turn leaks. iVaps with auto EPAP enabled results in lower average pressures vs BiPAP. The fact the Lowenstein has a similar feature is certainly something I will investigate and see if I can get my hands on one.
Your comment about PS failing to support or reverse the collapse of the airway also makes sense, Im pretty sure I have seen that in that no amount of PS, seems to be able to compensate if EPAP is too low. It may well be that the previous higher EPAP values I had tested before were simply not enough and I've been correcting the waveform with PS rather than EPAP.
I would be interested to hear how your experiment goes. This ability to adjust the waveform seems like a really valuable function. There seems very limited info on these devices, you have done a great job of mastering this device. When you referred to early collapse were you referring to the period from 10:49:10 onwards in your screenshot, where there is a slight ripple/dip in the dome after the peak.
RE: BiPAP Pressure for Possible UARS - Macka - 04-09-2024
No I wasn't referencing that screen shot, but last nights which I hadn't posted. Those little wiggles I think you are talking about though are in a position I would call late collapse of the second half of inspiration. Ones that start at zero up into first half, early collapse. If you draw a line down to mask pressure from an early collapse point in your fathers charts, you will see at what pressures this is occurring. Especially when the respiration rate is variable, the machine cannot get pressure up quick enough if you ask too soon for the breath. This is particularly so on a machine where rpm has to rise in the pump to give you this. This is another advantage of valve driven air delivery. The machine latency is far less and can respond to erratic demands better.
I did switch to ramp 3 last night and the wave form took on a more spiked and narrow one like a Resmed with a slight right lean in some breaths. I got more instability early on in inspiration and a few little second humps because of the late arriving pressure and flow. Interesting that the duration at peak pressure dropped off to make narrow spiked waveforms. I will go back to the middle setting of 2.
RE: BiPAP Pressure for Possible UARS - SingleH - 04-10-2024
Assuming I understood your comments correctly, I've marked lines in the areas after zero. The pressure at these points seems to be 10.5. When he was on APAP his sweetspot for good figures without leaks was 13 to 17. With his current setup his IPAP pressure is 9 EPAP+ 7.8PS = 16.8. I will shift the balance in favour of EPAP and see what happens.
[attachment=62474]
Is the Lowenstein Valve driven? I'm assuming the motor is simply constant 24/7 when in use and therefore the valve is regulating flow, I could imagine the benefit of this particularly for people with respiratory drive issues. With the Resmed I can hear it grinding its gears on the inhalation phase when I have listened to his device, which I can only assume is what you have outlined, with the machine attempting to respond to the collapse.
Whilst having a read I finally came across a Lowenstein product Matrix, annoyingly there is no breakdown of the 30ST, only a brief reference to its adaptive target volume feature, which I assume is its iVaps equivalent. In the second half there is plenty of interesting info on all the functionality and how their different tech works. You may be familiar but have attached a link anyway in case you want to read.
https://sleep.sante-group.com/app/uploads/2022/08/Lowenstein-Sleep-Products-Whitepaper.pdf
If you have time it would be interesting to see your before and after screenshots as you are changing your waveform.
RE: BiPAP Pressure for Possible UARS - Macka - 04-10-2024
You can really see when you reference the two charts together what story they tell. The pressure is barely risen off epap and is not matching the negative pressure being generated by the expanding lungs. Quicker breaths can make this situation worse. Based off this pattern 10.5 - 11 is where you would aim for EPAP or EEPAP to be. I believe this is a good example why resmed bi-level users find the highest trigger setting best. If you delay the pressure rise from epap at all, it is not good. The sooner you get pressure rising the better. For some users it is too late to wait until after an attempted breath.
This is where EEPAP pressure makes so much sense. It still allows EPAP to be lower and to start a good emptying of the lungs, but slowly adding back the higher pressure ready for event control and breath trigger. The air already moving and near instant valve response I believe, makes a big difference. On top of EEPAP, you may only need pressure support of 4 or 5. I have found it also helps dramatically with centrals by not over-ventilating you.
The sensation to breath out against a rise to EEPAP is not noticed by me at all these days. When I first started on a Prisma20a I used softpap3 in the first week. It felt a bit unusual to feel the pressure rising at the end of a breath. That feeling quickly passed. In that mode the Prisma20a was rising 3cm to EEPAP then adding 1cm on top. I am currently only using Bi-Soft 2 which is a 2cm rise and it is unnoticeable and very natural feeling. Bi-soft1 uses only 1cm.
Below are good sections from the last 3 nights. Ramp 1, 2, & 3.
You can see on 1 (the steepest), I am reaching peak too early and instability begins when IPAP is reached and plateaus. On ramp 2, any instability is more in the middle and the breaths are more even both sides of peak. Ramp 3 is mostly early instability but still passable. This small adjustment although subtle, shows how things can change easily. When the instability that is there, starts causing flow limitations, the effect of each setting makes itself felt more.
You should also notice the width of each pressure wave is changed with this setting. Because the machine is working to a set respiratory rate, changing the ramp rate is altering the trigger to exhalation and your volumes above the zero line. I think this shows behind the scenes these machine are still very driven by the factory algorithms, despite the settings they let you adjust.
Ramp1
[attachment=62516]
Ramp2 - this is what I use as it is the most comfortable and balanced, with peak pressure and peak flow, meeting in the middle of each breath. Part of the syncronicity puzzle.
[attachment=62518]
Ramp3
[attachment=62517]
RE: BiPAP Pressure for Possible UARS - SingleH - 04-11-2024
(04-10-2024, 08:46 PM)Macka Wrote: You can really see when you reference the two charts together what story they tell. The pressure is barely risen off epap and is not matching the negative pressure being generated by the expanding lungs. Quicker breaths can make this situation worse. Based off this pattern 10.5 - 11 is where you would aim for EPAP or EEPAP to be. I believe this is a good example why resmed bi-level users find the highest trigger setting best. If you delay the pressure rise from epap at all, it is not good. The sooner you get pressure rising the better. For some users it is too late to wait until after an attempted breath.
This is where EEPAP pressure makes so much sense. It still allows EPAP to be lower and to start a good emptying of the lungs, but slowly adding back the higher pressure ready for event control and breath trigger. The air already moving and near instant valve response I believe, makes a big difference. On top of EEPAP, you may only need pressure support of 4 or 5. I have found it also helps dramatically with centrals by not over-ventilating you.
Very good analysis here, I did find highest trigger setting worked best, and have him on high cycle also. There is also very much an issue with over-ventilation as you point out due to the high PS needed to keep his waveform stable, which in turn forces me to cut short Ti-max slightly as the only means left to control the CA's.
Just a thought, on the Vauto on S-mode, Easy Breathe is an available option which can be disabled given the ability to adjust Rise time is available, its not available on Auto unfortunately. I wonder if it would be worth trying a run on S mode at high EPAP 10/11 range with a short rise time?
Just to clarify is the Ramp, 1/2/3 setting the Lowenstein equivalent to Rise time setting? Its interesting as screenshot 1 shows a mask pressure waveform with the more right leaning waveform similar to the Resmed and interestingly your flow rate waveforms (at 2:48:30 and :37) shows a more flattened out waveform that I see on my "flow rate present" sceenshot.
RE: BiPAP Pressure for Possible UARS - bertchintus - 04-15-2024
Hey all! No worries about "derailing" the thread, more replies means more eyes on my post and I appreciate the responses. I am still not doing well and am experiencing excessive daytime sleepiness and mental/physical fatigue. I'll post last nights sleep data as well as a 2 minute snapshot. I see that there is a 2 hour window where my machine is turned off but I don't remember doing that, which is also odd because I am able to keep my mask on most nights without issue.
More importantly I saw a thread started by the user jkossis who seems to be dealing with similar problems to myself. @Sleeprider replied to that thread and mentioned variable rate and volume in their breathing and I was wondering if there is anything unusual with either of those when it comes to my own data.
If the above is true, are there any settings I should possibly change? Could it possibly be a change to my Ti Max or pressure support?
As always any help and advice is greatly appreciated.
RE: BiPAP Pressure for Possible UARS - TechieHippie - 04-15-2024
If you have smart start on, I think it does auto off as well. The leaks might have been high and interpreted as taking off the mask.
I suspect that first variability is while you are awake and falling asleep.
Is the second half of the night typical for even when you don't have the gap in the middle?
I would think your trigger settings might be the next thing if you haven't done them yet, I'm on my phone and can't look back.
I will let others address the rest, mainly I'm following along for my own education.
Lisa
RE: BiPAP Pressure for Possible UARS - bertchintus - 04-15-2024
Thanks for the quick reply TechieHippie! I would say the second half of that night isn't all too different than most nights, I'll post two more nights for comparison.
RE: BiPAP Pressure for Possible UARS - Macka - 04-15-2024
Hi bertchintus, you have a good amount of sections where every signal is flattening out for a substantial length of time. The Zoom of a good section showed perfect breath shapes for inhalation. This would explain to me why you have such settled periods. The only thing that doesn't look right to me is your persistent low tidal volume and high resp rate. I would raise min pressure and try add some extra volume to your breaths. This low tidal volume I believe causes periodic arousals and also the centrals that follow. If you eliminate this, I suspect your AHI will drop to virtually nothing. peaceloveandpizza suggested moving your minimum to 8 at the start of the thread. I agree you should start there and move up if necessary. Adjustment of your cycle and time at peak pressure may definitely be part of this equation. Be handy to have some experienced Resmed users wade in here.