[split] Mal777 Lumis 150 ST-A iVAPS Therapy

[Sleeprider]

That looks distinctly central, and as IPAP rose, respiration returned to normal or above. Respiration gradually diminishes and during the apnea, the airway seems to reflect pressure support and EPAP from the minimum pressure support. As pressure support approaches 10 cm, full or over-size breaths resume and follow diminishing pressure support back to another apnea that again resolves around 16 cm (PS 10). It appears to take 10-15 seconds for the machine to reach the higher pressure support. If this was present more frequently, we might increase PS min to avoid it, but there are relatively few events at this point.

Geer1's comment about trigger sensitivity may be something we try later to see if it can reduce the number of breaths per minute. At this point the machine is following your spontaneous effort and supplying about 4-cm of pressure for each detected inspiratory trigger. I'm undecided if the answer is the trigger sensitivity or increased PS to make every breath count. I'm still where I was with the last post, reluctant to jump to any conclusion or make changes until we see more time n therapy.

On second thought, I think since the titration protocol recommends EPAP min at 5.0, we should increase Min EPAP to 5. Also, my inclination is to move toward increased PS rather than rely on trigger for significant changes. An increased PS min would have potentially reduced the duration of the UA events, and might have slowed the respiration rate where it was approaching 20 BPM.

[SarcasticDave94]

Sleeprider covered it better than I could.

[Mal777]

Most of the events seem grouped in clusters so maybe positional issues add to the story? I have had positional problems in the past when laying on my back just before sleep...

So for tonight I'll increase EPAP minimum to 5.0 as per titration protocol, and no other changes?   I agree we haven't had long to analyse the new data (under 3 hours), and better to wait to see another full night of data before doing anything too drastic

Because I'm having some discomfort and trouble getting to sleep with the STA, is it OK to use ramp tonight for 15 minutes, with minimum epap 4-5?

[Sleeprider]

It it helps to sleep, then help yourself. We will hopefully have plenty of time to see how your respond.

[Sleeprider]

Just looking back at older results, we can see a big change. here we svaw long clusters of OA tha may have been positional, and a very unbalanced inspiration vs expiration flow graph that looked like a hair brush. The new results see to not have that.  Peak respiration rates have dropped back, but we want to see more progress in this area, and your tidal volumes and minute vent are not radically different but with somewhat more consistent respiration. That is probably a good thing,  Overall, I think we are seeing some significant improvements, and we just need to patiently build on that.  

[Mal777]

Thanks for posting those Sleeprider. Yes there is a big improvement. Tonight EPAP min 5.0 with 15 minute ramp and will see what tomorrow’s report brings ?

[Geer1]

Increasing PS might help keep spontaneous flow rate stay positive therefor avoiding a drop in IPAP but if it doesn't do that then I am afraid it will increase ventilation further (already 12-13 LPM) by making these short breaths even more pronounced. 

I agree with just upping EPAP to 5 for now and giving it another night to see what more data looks like. Personally I would also lower trigger sensitivity a notch just to see if it appears to have any affect, EPAP won't be affecting these odd shaped breaths so you can try both at the same time imo. 

Btw I stumbled upon this clinical guide which could be helpful if you haven't already found one. 

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[Sleeprider]

Yes I have the ST-A clinical manual and it can be requested through the forum at the CPAP manuals link at the top of the page. https://www.apneaboard.com/adjust-cpap-p...tup-manual To continue distributing manuals as an educations site, we do not allow posting from other sites.

[Mal777]

Yes, I have the ST-A clinical manual thanks 



Another thing I have noticed comparing my best average over 5 nights, (when RR was most stable)  of my Minute volume , it was 8.1 median on the Airsense.  last night it was 13 on the Lumis ST-A .
Also my Inspiration time on Airsence averaged median 2.4 and on the Lumis last night was only median 1.28

I guess tomorrows resuts will confirm if this is an issue, and we can make necessary adjustments

[Geer1]

Mal that is the issue I was pointing out. When you look at the zoomed in portion you can see exactly what is happening once you understand how this machine works. Instead of getting one normal breath the machine is forcing you to take 2 short quick breaths with a quick exhalation in between. If you tried to replicate that it would be fast almost hyperventilation type breathing.

With the autoset APAP you were using before everything relies on your spontaneous breathing. Your spontaneous breathing much of the night has strange oscillations that are not normal (have seen them in a few other members but not many and not near as often as yours appear). It is hard to know what causes that breath waveform but in effect what is happening is something is causing you to exhale when you should be inhaling and inhale when you should be exhaling. Random guesses on my part include stuff like diaphragm/chest muscles not in sync(asynchronous breathing), diaphragm spasming, amplified cardiogenic oscillations. This is why I was hoping a pulmonologist would review that and it frustrates me to no end how these guys refuse to even look at OSCAR data. Perhaps the only way to get them to review the data is to give them your CPAP SD card data and tell them they have to look at the flow rate data however they are capable of doing so if they aren't going to take your word for it. I also thought that your titration study would have commented on this but it doesn't seem that they did, I don't know if that is because it didn't happen or because the mode and settings they used were able to mitigate it. One thing that you could do that might help understand what is happening is setting up a camera to record yourself sleep and perhaps that would give some hints.

With the ST-A you have timing controls which are manipulating these strange oscillating breaths into the short breaths you see now. I highly recommend you review the clinical manual and what I post here to make sure you understand these controls as I believe they are very important in your situation. If there is something you do not understand about them please ask. The first control that comes into play is trigger sensitivity. The higher the trigger sensitivity the sooner the machine will start to supply pressure. Next is rise time, the shorter the rise time the faster the machine will build pressure. Then Timin which will hold pressure on for a set time (Timin) regardless of what your spontaneous effort during that time. Then you have cycle sensitivity, higher the sensitivity the sooner the machine will cycle back to lower pressure (EPAP). Then you have Timax, if you don't spontaneously start exhaling before Timax it will lower the pressure to try and force you to exhale.

The issue here is that these timing controls are started by spontaneous effort. When the first oscillation in your breath prematurely passes the 0 flow line then IPAP pressure is being triggered (due to trigger sensitivity), it is raising pressure faster than your old machine (because of rise time) and it is maintaining pressure for a minimum time (Timin) effectively forcing you to take a breath. If I had to guess most of the short breaths you posted end as soon or shortly after Timin is over then your body takes a quick exhale (because it didn't even get to finish exhalation process before getting pumped up again) and then the whole process repeats. During this whole time the machine is pretty much forcing you to breath at a rate that does not match your spontaneous effort and everything is out of sync and other than providing more ventilation I am not sure it is a better result than what you had on APAP. 

Here I show this in pictorial version (what is happening and what I would like to try and make happen). This is one of your examples of breathing from APAP. 

   

Trying to fight this with PS would make sense if they were flow limitations but I don't believe that they are because flow limitations restrict flow, not change its direction. Increasing PS could still work but if we are fighting chest or diaphragm etc I don't know that it will help do anything other than create more pressure and more ventilation in the same form of breathing. 

If we could use timed breath mode in conjunction with iVAPS mode that is what I would have already proposed as I believe it might have merit with this situation. I do like the advantage of iVAPS over timed mode because your sleep study shows not only a comment about hypoventilation but also data of dropping O2 levels because of it. iVAPS allows us to use an oximeter to monitor O2 levels and increase target Va until desats are no longer present which was going to be my recommendation after we get the basics working properly. 

And this isn't just based on my opinions(other than my opinion that you have a synchronicity problem). From the Resmed titration protocol.

Adjust TiControls and Synchrony features if • Chest wall movement is not in sync with mask pressure tracing

For SpO2 < 90% with all respiratory events eliminated: • Increase Target Va by 0.3 every ≥ 5 min until desaturations are resolved

When to adjust the trigger sensitivity threshold? The Medium (default) setting will be ideal for most patients. A Low (or Very Low) trigger sensitivity setting is recommended for the following conditions: • Cardiogenic oscillations and subsequent auto-triggering

I am sure trigger sensitivity should be decreased. I am not so sure about Ticontrols and rise time and feel we need to adjust trigger sensitivity first to figure out ideal settings. 

Also if I haven't stated this yet, I have a hard time believing this breathing is due to sleep apnea or airway restriction. You do have other central apnea issues primarily during sleep transition, I'm not sure if they are related though.