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+--- Thread: Auto bipap -- the auto doesn't respond! (/Thread-Auto-bipap-the-auto-doesn-t-respond)
Auto bipap -- the auto doesn't respond! - dcg494 - 08-11-2018
Hi all,
I've noticed that my phillips respironics dreamstation bipap auto function is kind of lame -- the auto rarely ever responds to events, and then it only responds for a short while. What's the point of having an auto function if it doesn't do much ? The screen shot is of as typical night (a pretty good night in terms of AHI though)
I have UARS, with more small flow limitations (arousal index ~40 per hour). Is it possible the phillips respironics machines just aren't up to the task of UARS ?
Are resmeds maybe better ? I hear the Resmeds are more responsive -- is it worth trying out a resmed Vauto ?? Or the autosense for her which is even more responsive (so i hear) ?
Thanks a lot everyone!
RE: Auto bipap -- the auto doesn't respond! - Walla Walla - 08-11-2018
Erased my post as it didn't apply. Have no idea what I was thinking.
RE: Auto bipap -- the auto doesn't respond! - Sleeprider - 08-11-2018
Your Dreamstation BiPAP Auto is set for a minimum EPAP of 6.0 with PS at 3.0 to 4.0 and IPAP max at 10.5. The settings are at fault here, not the machine. For your UARS and hypopnea, you need to increase PS min to 4.0 and possibly higher, and the IPAP max must be increased to 14.0 to give the machine some room to operate in auto mode.
While I prefer Resmed Vauto, your Dreamstation is handcuffed to low pressures by the IPAP max limit. Do not rely on the variable PS feature of the Dreamstation. With UARS you need higher minimum PS. If using a range, start at 4.0 to 6.0.
RE: Auto bipap -- the auto doesn't respond! - dcg494 - 08-13-2018
(08-11-2018, 07:40 AM)Sleeprider Wrote: Your Dreamstation BiPAP Auto is set for a minimum EPAP of 6.0 with PS at 3.0 to 4.0 and IPAP max at 10.5. The settings are at fault here, not the machine. For your UARS and hypopnea, you need to increase PS min to 4.0 and possibly higher, and the IPAP max must be increased to 14.0 to give the machine some room to operate in auto mode.
While I prefer Resmed Vauto, your Dreamstation is handcuffed to low pressures by the IPAP max limit. Do not rely on the variable PS feature of the Dreamstation. With UARS you need higher minimum PS. If using a range, start at 4.0 to 6.0.
Got it, thanks Sleeprider. Only issue is aerophagia and centrals -- i found that my pressure limit for any extended time is a bit over EPAP 6.5 / IPAP 8.5. I can tolerate pressures higher than that, but only for a little while. And PS 4 seems to be where centrals start to kick in.
That's why I wish I could rely on the pressure support range and auto responding more quickly.
Ah well, worth a shot -- I'll try cranking up the PS range to 3-5 and IPAP limit to 14. And keep Epap min to 6 or lower it to 5.5.
RE: Auto bipap -- the auto doesn't respond! - Sleeprider - 08-13-2018
I missed the part on aerophagia and the complication of centrals. Therapy under those conditions tends to be a game of compromise to find tolerable settings that produce tolerable results. First step is of course to find the absolute minimum EPAP that you can tolerate to resolve OA most of the time, then use the pressure support for hypopnea and flow limitation, up to your tolerance that does not trigger centrals. For responsiveness the Resmed is definitely faster, but will also keep you closer to the top of your range.
I think in cases like yours where there is a sensitivity to pressure support causing centrals, the use of Enhanced Expiratory Rebreathing Space (EERS) is promising. http://www.sleepmedicineusa.com/UserFiles/File/Treatment%20of%20Positive%20Airway%20Pressure%20Treatment-Associated%20Respiratory%20Instability%20with%20Enhanced%20Expiratory%20Rebreathing%20Space%20(EERS).pdf
We had a thread where we discussed the use of this technique here: http://www.apneaboard.com/forums/Thread-Switched-from-ASV-to-CPAP-finally-getting-some-sleep?page=2
RE: Auto bipap -- the auto doesn't respond! - dcg494 - 08-13-2018
Excellent, thanks! Came across those threads before, and read an article about diamox being really helpful in these cases too. To be fair, I've only tried PS at 4 a couple nights, and I think I can try to see if my body gets used to it over time.
I have very very few OAs even at EPAP 4.5, and 6.5/7 seems to eliminate them completely. But I found that Hypopneas are higher at lower EPAP pressures too -- and I seem to get some H and FLs at expiration when EPAP is lower.
I read conflicting messages on this -- some say obstruction during expiration doesn't happen. Others say it does. Still others say it rarely does, and that the EPAP just has to be high enough to keep airways open enough so obstruction doesn't happen at end of expiration.
Wonder which it is ?
RE: Auto bipap -- the auto doesn't respond! - Sleeprider - 08-13-2018
Expiratory flow limitation can clearly exist, but it practically defines COPD or other severe restriction condition. If you do a search for expiratory flow limitation there are many articles exploring the topic and you can decide if they have applicability to you. Most flow limitation treated by xPAP is inspiratory, and it responds to an EPAP pressure that stabilizes the airway preventing obstruction from happening at the end of expiration as inspiration is triggered; and it responds positively to pressure support to improve flow during inspiration when upper airway flow restriction may cause flow limits. I think the moments just prior to spontaneous inspiration are critical for EPAP pressure as this is the time that flow rates approach zero and only the CPAP is maintaining the airway. Expiration is considered passive for most people, and during sleep there is not a particular muscular effort required for expiration. This is in contrast to inspiration which is caused by expansion of the chest causing negative pressure in the lungs and airway. This negative pressure is what leads to obstruction in those of us with an airway prone to closure and positive pressure is maintained when using CPAP/BPAP.