Starting ASV therapy - 1st night results and questions

[00derek]

Hello again,

I joined the forum in December 2022, using CPAP. At that time Sleeprider looked at my Oscar chart and stated outright I needed ASV due to central apneas. He was correct. I changed doctors and DME providers, and long story short, I used my new ASV machine for the first time last night.

Here is the chart - I haven't studied it too much myself, as I need to refamiliarize myself with the terminology etc.

   

My Rx from a clinic sleep study was Min EPAP of 5, Max EPAP 10, PS 3-15 cm of water. I think the DME set the min EPAP to 4, but I'm not sure if that's causing my problem....

After the 10 min ramp, while I was still awake, the pressure during my inhale was too strong - machine was pushing more air than I wanted. In other words it was more than my respiratory rate demanded. I'm a fairly shallow breather while awake, and the only way to be comfortable was to take large breaths on every cycle to take the air that was being supplied.

I thought ASV adapted to my breathing rhythm? Also, why is it providing pressure when I'm still awake and breathing normally, shouldn't it increase pressure only when it detects an apnea?

I think the machine actually woke me up while I was dropping off to sleep, so I quit after 1 hour. FYI I turned off the ramp at 22:10, but it was on at 21:25 when I started.

Mode is ASVAuto. I can't change IPAP numbers, should I lower PSMax to get less pressure?

   

Many thanks for your help.

DM

[DevinJones]

Hi DM, your experience with forced pressure beyond what you want or need is a common problem with the ResMed AirCurve 10 ASV when the pressure settings are set too wide or too high. When the device is set to the default pressure settings, the autotitration often does not work properly for many users and as it is designed to work.

You can read more about this problem in my thread here:

https://www.apneaboard.com/forums/Thread...-you-agree

Also, you can read about tcolar's struggle to find pressure settings that effectively treated his apneas without runaway high pressure from his AirCurve 10 ASV. In the following thread, he said, "I wish I could have the PS higher, and the ASV only use it in a short burst when needed, but it tends to go and stay at the higher pressure for a while, to prevent further events I guess, but if it stay over 10 or 11 for more than 30mn, I wake up bloated."

https://www.apneaboard.com/forums/Thread-New-on-Bipap-ASV-have-a-few-questions

Fortunately, however, tcolar found a solution:

"Anyway to be able to not wake of aerophagia I had to set the ASV to the lowest settings EPAP of 4, PS os 0-5, anything above that and aerophagia starts :-/ , but my apnea is treated well at those setting so no complaints."

I, too, now have my AirCurve 10 ASV set to low settings (EPAP 4/6 and PS 0/5) and can sleep seven to eight hours with a low AHI and without frequent, disturbing high-pressure surges. If a rare pressure surge occurs, turning the device off and on resets it and stops the pressure surge. Although others have talked about blowing into the mask to reset the device, that does not work for me and many others users.

[DevinJones]

DM, see also Sleeprider's explanation about how some ASV users may not need high pressure support to prompt them to breathe if they can breathe on their own with a more gentle pressure cue. 

https://www.apneaboard.com/forums/Thread-Resmed-ASV-Lowered-AHI-but-High-Aerophagia?pid=476314#pid476314

[00derek]

Thanks, I'll have a look at those threads.

[Sleeprider]

00Derick, good to see you back with the ASV. DevinJones raises a good point, and we probably have some room to improve your results. The first chart is only an hour of therapy, so we can't tell very much from it, however it looks like you could use a higher EPAP min at 5.0, and we may adjust that based on results. In your charts, please use the Mask Pressure instead of Pressure chart. That lets us see the breath by breath machine response to your respiratory flow. Hopefully you can get more time in therapy in your next session. ASV is not easy to get used to, and I think a full face mask is especially challenging as it tends to move and bounce with changes in pressure support.

[00derek]

I'm going to press on for 1 week with the settings as they are from the DME (= the Rx). I feel like I didn't try hard enough with the CPAP - even though it was the wrong therapy. I struggled to get to sleep and never wore it more than 2h per night.

But I've made to to 4h for the past 2 nights with the ASV. I am falling asleep fairly normally and I think I could get to a full night if I persevere.

Last night I woke up with extremely dry mouth - what's your opinion on mouth taping with a full face mask?

Between the CPAP and the ASV I was taping every night and I'm pretty sure it helped a lot.

Thank you

---

....ps

I'm interested in monitoring my O2 during sleep.

Anyone got recommendations for some gear to do that?

I have a finger oximeter but I don't think it has any way to transmit data

[DevinJones]

I really like the Wellue SP-20 Handheld Pulse Oximeter. It is a professional, medical-grade pulse oximeter that is not too expensive, especially with a promo code.

[raylock1]

I like the Wellvu wrist mounted unit.  I import the data directly into Oscar,  so it displays in the Oscar reports.  I also need to tape my mouth (or use a chin strap) with my ASV to prevent dry mouth even when using a full face mask.

[00derek]

Here is an update after my first week. I did get the Wellvue/Viatom checkme O2 max oximeter and have been using it the past 5 nights. So I have quite a bit of data to look at.

The good

• I have found the ASV easier to get used to than the CPAP; the headgear and mask are very similar so the difference must be the therapy. I wore the mask for >4 hours most nights, and 8 hours last night. 
  
• My untreated AHI was 31.5 - AHI over the past week has ranged from 0.2 to 7.5
  
• when I'm wearing the mask my SpO2 stays above 90% - without the mask it falls as low as 87 several times per night
  
• so far I feel marginally better in the morning with therapy than without. 
  

The less good

• mouth taping has helped reduce the air swallowing, but it still happens
  
• the machine is still not in sync with my breathing rhythm, it's pushing more air than I naturally feel like inhaling, and blowing back doesn't stop it
  

Here is my best and worst AHI from the past week - I'm curious about last night. I had quite a few hypopneas but didn't see any any O2 drops <90 - presumably that's when the machine is doing it's work to keep me breathing?

Another question; I understand the ASV is adaptive - the A in the name - but does it remember my breathing pattern from one night to the next, or is it only adapting in real-time? Is ASV supposed to prevent apneas altogether or just respond to them in the form of pressure increases?

   

   

Thanks

DM

[Sleeprider]

Resmed ASV uses a three minute moving average to monitor and determine an appropriate target minute ventilation, set to 90% of their most recent minute ventilation. This target threshold prevents under and over ventilation by dynamically increasing or decreasing inspiratory pressure support (IPS) as needed. The ASV uses a default respiratory rate of 15 BPM but adjusts that target based on the 3-minute moving average patient respiration rate. In answer to your question, the machine "learns" your rate and volume to set target respiration rate and minute vent continuously, but does not retain that information night to night, or even through the same night. More in the Wiki https://www.apneaboard.com/wiki/index.ph...tion_(ASV)

Your worst night looks like it had a couple positional (obstructive) clusters. https://www.apneaboard.com/wiki/index.ph...onal_Apnea