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RE: AirCurve VAUTO vs AST - Sleeprider - 05-14-2020
Brain fart I guess. I just haven't seen the acronym in a while. As said above, ASV is not a solution, and it is most commonly treated with bilevel or bilevel ST or ST-A. Any of those will work if you don't need a backup rate, which seems to be the case here. The most comfortable is going to be the Vauto. The real trick is to increase pressure support without suppressing the respiratory rate in order to affect minute vent. The only machine of the bunch that really does it all is the Aircurve 10 ST-A with iVAPS (intelligent volume assured pressure support).
RE: AirCurve VAUTO vs AST - DayWalker - 05-15-2020
Sleeprider,
Thanks for the clarification again.
On a side note, what is the normal SpO2 during sleep? I had a bad sleep last night (2 episodes with 3 hours each) but the saturation was on average ~90%-ish and it was dropping go 86-87 at a time with 1 drop to 76 for a second which I think was a glitch. It is very uncomfortable sleeping with this Air 10 oximeter for ResMed machines... I almost hang myself...
Cheers,
RE: AirCurve VAUTO vs AST - alshayed - 05-15-2020
I'm curious what Sleeprider thinks but from what I've read "normal sleeping SpO2" is probably anything >= 92%. Less than 90% is low, and in the US Medicare criteria for supplemental oxygen without comorbidities is <= 88% for >= 5 minutes.
However for OHS the treatment is based on ensuring ventilation is "adequate", reducing partial pressure of CO2 in your blood, and keeping SpO2 >= 90%. I don't know for certain what is technically considered adequate ventilation but to start the tidal volume should be at least 6-8 ml/kg IBW. Presumably that needs to be at a minimum respiratory rate of 10-12. I think normal respiratory rate is considered 12-20 for adults. The Philips titration guide suggests starting with a backup rate of 10 and tidal volume of 8 ml/kg IBW.
BTW if you use ResScan it can tell you the number of minutes below xx% SpO2. I wish OSCAR had that ability...
RE: AirCurve VAUTO vs AST - Sleeprider - 05-15-2020
I agree with alshayed, 92% is a good target but anytime there are frequent desaturations to 90% or less it is a concern. I believe over 5-minutes at 88% qualifies for supplemental oxygen. Brief events without a pulse response (pulse rate will usually increase on desat events) can usually be disregarded. Oxygen levels can be improved by increasing positive end expiratory pressure (PEEP) or by increasing the fraction of inspired oxygen (FiO2). PEEP is equivalent to the EPAP pressure of a bilevel machine. The objective with bilevel therapy is to use PEEP to maintain oxygen at an acceptable level and to use pressure support to improve ventilation volume which will reduce CO2. These need to balanced so as not to over-ventilate and cause central apnea, and there are limits to pressure that is tolerable for most people. If objectives to maintain SpO2 with PEEP are unable be be maintained, then supplemental oxygen can be added to the breathing circuit as described in our Oxygen Bleed wiki. http://www.apneaboard.com/wiki/index.php/Oxygen_Bleed_with_CPAP
RE: AirCurve VAUTO vs AST - DayWalker - 05-15-2020
Thank you for all your input. Unfortunately, I didn't have a good sleep last night. I had 2 sessions... 3-4 hours each and the first one had bad SpO2 levels but I was turning and tossing a lot while the second was calmer. Still, Oscar shows a medium SpO2 rate of 90% with drops to 86 on the second... Not sure if that is good or not. please chie in.
I am attaching the two screens. Pulse also goes up/down a lot, obviously due to the drop in SpO2.
RE: AirCurve VAUTO vs AST - alshayed - 05-15-2020
Ideally you want the SpO2 to be >= 90% all night which would probably put your median SpO2 at 92% or 93%. You can try bumping your minimum pressure up to maybe 9 if you can tolerate that and see how much that helps. Just keep an eye on controlling your leaks and whatnot.
IMHO it's hard to predict the effect if you do have a hypoventilation problem because you run up against a limitation of how much oxygen your blood will absorb easily when you are retaining CO2, if I understand the science correctly. As you increase pressure support with the VAuto that should help tip the scales more towards better oxygenation due to hopefully higher tidal volume assuming your respiratory rate stays somewhat stable (which would scrub more CO2 from your blood). But if it goes down and essentially keeps the minute ventilation the same then you may have to move on to a mode with a backup rate.
WRT "good sleep" if you've just started, your subjective quality of sleep may improve as you acclimate to the therapy more. Also you may find a noticeable change when you switch to the VAuto and try higher levels of pressure support.
RE: AirCurve VAUTO vs AST - DayWalker - 05-15-2020
Alshayed,
Thank you for your reply. I am currently on Autosense 10, not the VAUTO. I will have the VAUTO in a month or so.
Besides upping the pressure to 9 and try it to see if it make a difference, is there anything else I need to change to see if this would improve the SpO2 numbers?
FYI at the beginning with the full mask, the pressure was higher and it was even choking me and indeed my daily random SpO2 spot checks were 98-99% and I felt better and not drowsy during the day. Since I switched to nasal N20, this 'feeling' dropped. It is still better, but not this 'wow' effect from the beginning. Unfortunately, I can't stand a full mask...
Please advise,
RE: AirCurve VAUTO vs AST - Sleeprider - 05-15-2020
Is your current therapy comfortable? If so, then the correct solution for low SpO2 is a higher minimum pressure. Even if it does not stop more apnea it results in higher "Positive End Expiratory Pressure" (PEEP). This recruits more lung volume and improves oxygen transfer across the alveolar membrane. As long as you tolerate the pressure, you can improve your SpO2 with higher minimum pressure.
RE: AirCurve VAUTO vs AST - DayWalker - 05-15-2020
Sleeprider,
Yes, it is comfortable. Not a big fan of pushing, but I guess this would get corrected with VAUTO once it arrives.
With autosense I even started with 4-20 and AutoRamp. I hated it, so I asked the doctor to up to 6-20 and I turned off the AutoRamp, then I did increase it myself to 7-20. I can have no problem going to 9-20 as 8-10ish starting is where I feel most comfortable, otherwise, I feel like I am pulling too much.
In any case, it won't hurt trying and I will post the results.
I called my pulmonologist today and asked what is the difference between nasal and full-face since there is a different feeling after I wake up with either and he said exactly that... pressure. Nasal is less while full is more pressure. I see it with the Oscar results too. The average pressure is 6-7 to 9 on nasal and 9-12 on a full face mask. My N20 is set on pillows as suggested too. Not sure if that makes any difference than nasal.
Not to mention that I have a moderate case of a deviated septum...
RE: AirCurve VAUTO vs AST - DayWalker - 05-16-2020
alshayed and Sleeprider,
I upped the minimum pressure to 9 as suggested. Here are the results. I see it as a way better than with 7 but your input would be greatly appreciated.
Cheers,