New to me, ASV, Initial Questions

[Sleeprider]

I'm sorry to hear you were not able to get the ST-A dialed in before you needed it.  I'll try my best, with information from your previously posted Oscar charts and the information contained in the Resmed Clinical Titration Guidelines. https://document.resmed.com/en-us/docume...er_eng.pdf

First, set the machine to iVAPS mode. I think we need to keep  your current EPAP of 7.5 cm. We will keep PS min 3.0 (Resmed recommends 4.0) and he Resmed recommended PS max 20.0.  Set the iBR to 12.0 breaths per minute. This is below the recommended 15 BPM, but above your recorded respiration rate. To set Va (alveolar vent rate) you should calculate your ideal body weight for your height in Kg, and multiply by 6.0 mL/Kg. Based on prior results this is going to be near 450 mL based on ASV results, however use this calculator to determine IBW and multiply Kg by 6 and see what you get. https://www.mdcalc.com/ideal-body-weight...ody-weight

I'm pretty confident the ST-A in iVAPS mode is going to be much better for you.  I would like to see you using a recording oximeter during the titration phase so we can track actual blood oxygen saturation.

[SarcasticDave94]

Here's ResMed's titration process for the ST-A in a screenshot.

[attachment=31756]

OK a clarification on my earlier post on the ST-A setup. To run iVAPS MODE, you need to run Learn Targets below the mask setting in the clinical menu. It will compute a Target Va and Target Pt Rate. You may also manually input the units required. I'm the clinical manual, this Learn Targets is discussed on page 23.

Be certain you have your clinical manual to set this up!

iVAPS mode is going to be somewhat similar to ASV mode with static EPAP and PS range.

[Whitenoise]

I know all you folks do this for various reasons but I feel it's so very appropriate to still let you know how truly outstanding you are, and how grateful I am for your untiring devotion to helping others to help themselves.

Dave, Sleeprider, Jaswilliams, and all, Thank you,,

This looks like enough for me to start with and I know you did some digging to come up with this strategy and place information at my use.
I'll look into the recording oximiter, and agree 12 RR sounds like the right # to start with and understand that the intention is to increase the alveolar vent rate for healthy not current health state which is compromised.

I'll see how it goes and report in after I have something more. (I may even be able to fix that ASV switch now)

Jim

[SarcasticDave94]

Good luck to ya. Report on how you feel and give an OSCAR on it.

[Whitenoise]

Made it through the learning setup today in iVaps mode which took 20 minutes and then had to be "accepted".
As it learned it initiated quick inspiration "steps" followed by an expiration cycle which continued as long as it sensed further attempts
to breathe in. Was an odd feeling, but not unpleasant. I typically breathed in 3 to 4 "steps", where as one with larger lung capacity would likely have increased numbers of "gulps" or "puffs" for the monitoring of my breathing.

After accepting the machine continued on and I continued in an awake mode for 1.23 hours or so and it displayed a report as follows,
AHI 2 then updated to 1.0, pressure 23.4, (pretty high) exp pressure 7.3, 8 L /min leak rate, VT 700 ML, I:E 1:2.8, RR 11,MV 7.51 Min, Ti 1.4 second Spont trig 83% sont cycle 27%AHI 1.4 Total Ai 0.0

I likely didn't give a true normal breathing pattern as I found myself breathing deeper than usual getting used to the test and subsequent awake breathing extended after lean mode. simple oximiter test showed 98 O2 throughout and my usual elevated pulse at 88.

I could take spontaneous breaths and or hold off and it wold initiate one sometimes quite forcefully. Had many bursts of PS 20 for a total of 27 but they didn't last long.

I'll give it a go for sleep tonight but did increase the generated PT Rate of 9 to Sleepriders's 12 and VA to 4.5 not generated 5.5 which may have been artificially elevated during the learn process. Ideal body weight VA was less than 4.5 so will start out with the ASV's 4.5 if I have that correct. that right.

Set Ti max to 2.0, ti min to .3 rise time 30 ms trigger sensitivity med and cycle med and PS min 3 PS max 20. Am hoping this reduces the high pressure bursts which buzz my mask beyond its limits a bit.

Off to bed soon.
Good Night up date how it went in the morning.

Jim

[SarcasticDave94]

I could be wrong, but me thinks the ST-A is supposed by OSCAR. If it is, you feel like posting a shot after next use?

PS edit... OSCAR 1.1 works with this according to the wiki. Maybe then 1.2 will too but I dunno for sure. Look for comments from those others that know more than I.

[Sleeprider]

I'm certain Oscar will support the ST-A, and if not we will invite you to share your data card so the development team can look into it. Good luck on therapy, and I don't think there were any surprises from your trial. In the few times we have seen this machine used in trial mode, the users all had higher than normal respiratory volume. It's very difficult to think about how you breathe when asleep.

[Whitenoise]

First night Resmed ST-A ok, as in I wasn't easily awakened, however we have some significant tweaking to go clearly with a 14.4 AHI,
Events = 70 Hypopneas and 30 Unidentified Apneas over a 7 hour sleep period with leaks from the high pressures.

Learned Target PT of 9 was changed to 12 (IBR) and learned Target VA of 5.5 L/Min was edited to 4.5 L/Min as I felt it may have been artificially high due to my breathing deeply during the 20 minute breathing period monitoring in iVAPS initial setup. *Note Ideal Body Weight for height KG x6 was lower than the 4.5 L/min we considered from ASV data. Perhaps 5.5 L/min should have been used.
I am unclear thus far how best to utilize Ti max and Ti Min Rise time trigger sensitivity and cycle sensitivity as regards Respiration Rate and would ask for better understanding.

Breathing in ST-A felt clipped during inspiration and I felt I required deeper and or longer lung filling to be satisfied. Can over ride with drive effort during an inspiration and receive more air, but my trigger and cycle sensitivity at medium may have need to be altered?

I'll include  charts.  ST-A mode settings don't seem to appear in OSCAR 1.2 in provided charts. EPAP was 7.4  PS min was 3.0 and PS max is at 20.  Did manually enter height based on my normal adult height not current age minus 2 inches so it could determine closest normal lung capacity.

3 charts. Full night, some event free wave forms, mixed H and UA closer.

   

   

   

[Sleeprider]

Do you have the clinician manual? If not it is available from the forum.

You have a TiMin setting, we may need to increase it, and perhaps increase rise time. What are your current settings for TiMin and TiMax and rise time? While we're at it give me your trigger and cycle sensitivity. I suspect you will want high trigger sensitivity and low cycle sensitivity to avoid the feeling of clipped inspiration. It appears your median Ti is 1.9 to 2.0 seconds. We can set Ti Min to allow a minimum time of inspiration, as long as we give you enough time in your normal respiratory rate for expiration. At 12 BPM, the average breath cycle is 5-seconds, so as we increase Ti Min to 2.0, the time for expiration falls to 3.0 seconds. The Resmed recommended TiMin is 1.0 seconds at your breath rate and TiMax is 2.0 preserving a 1:3 I:E ratio. If you are currently at 0.3 we can move to 0.8 or 1.0 and see how much difference that makes before going higher. It really depends on how much control you want input in the machine and the degree of spontaneous inspiratory effort you are able to provide. Rise time can slow the time it takes the machine to reach IPAP, and a longer time should make it more comfortable.

Observations: The target Va may be too great and is resulting in these very high IPAP pressures. I suspect rise time is too fast and TiMin too low. I think we should look at closeups of some of the events to see why these hypopnea and UA are being flagged. If the problem is obstructive, we may want to increase EPAP.

[Sleeprider]