Difficulty Adapting To ASV Device

[ajack]

This isn't need yet, but it gives an idea.
when you start getting comfortable in a couple of weeks. The min EPAP can raised till the UA and H are controlled. You won't have CA any more, as resmed says it's 100% controlled. The only other thing is your minute ventilation and see how that charts. A person on another forum needed a min PS of 6 to get their o2 above 90%, some need to move to VAPS
"Hey that pressure support increase you suggested for me seems to be working now, thanks very much for the recommendation! I set the PSMin. to the maximum the S9 ASV unit would allow, 6.0 cm (it won't go higher), and the PSMax. to 11.0 cm. If I take PSMax. any higher, I get headaches - perhaps my sinuses are sensitive to higher pressure, who knows. I am staying above 90% sPO2 now, which for me is good."

[tmoody]

I've been on ASV for a year and a half now. My initial experience was similar to OP's, especially in terms of the difficulty in falling asleep. The machine gave me the distinct impression of trying to "take over" my breathing, resulting in resistance from me, high pressure blasts, and so on. Using the ramp is a good idea, but it might be necessary to raise the ramp minimum pressure to find the comfort zone. Other than that, I can also confirm that I have better sleep with a low PSmin. It's been at zero for several months now, and zero was what was prescribed in my titration study. I only raised it as I was experimenting to get lower AHI, but eventually I found zero was giving me the best results.

[ajack]

Yes, that's exactly the case, some people like yourself are fine on min PS:0 Some people are struggling on min PS:6 to keep an adequate minute ventilation/tidal flow and have o2 above 90%.

The default setting are started in a lab and titrated to what the person needs. A lot through the doctor and DME are skipping this step and are given ASV with the default setting. The DME people who are advising then aren't really qualified on advanced respiratory needs, as are some sleep doctors. These are being sold as plug and play when it really isn't the case.

[Sleeprider]

Yes, that's exactly the case, some people like yourself are fine on min PS:0 Some people are struggling on min PS:6 to keep an adequate minute ventilation/tidal flow and have o2 above 90%.

The default setting are started in a lab and titrated to what the person needs. A lot through the doctor and DME are skipping this step and are given ASV with the default setting. The DME people who are advising then aren't really qualified on advanced respiratory needs, as are some sleep doctors. These are being sold as plug and play when it really isn't the case.

While minimum pressure support may affect tidal volume and minute vent, it is not the primary actor in improving oxygen perfusion, which is based on PEEP. The problem with higher pressure support in individuals using ASV is that by increasing pulmonary exchange, what it does is mainly to reduce CO2, which depending on the respiratory drive disorder, may reduce spontaneous respiration in patients with central and mixed apnea.  I think you need to be very careful in advising on increased pressure support, as it is not necessarily a good thing in all people.  Many people on ASV, require it due to CPAP onset centrals and primary central apnea.  Neither of these benefit from a high minimum PS, but rely on adaptive maximum PS to induce breathing during central apnea and hypopnea.  Most of these people failed on bilevel without backup rate with PS of 4+, and if my observations here are generally true, the PS made their apena worse. JMHO.

[ajack]

A lot of times I miscommunication what I'm trying to get across, It seems when there is a backup rate, it doesn't matter if treating their oa/h makes the CA worse. If raising the PS to high numbers to get normal tidal volume to get o2 above >90%, also increases the CA rate. The CA rate seems secondary to o2 . The back up rate sorts the CA and is the final adjustment, it comes with/after everything else.

Your link was where I first saw these things talked about. As you know, this is how they titrate, OA/H with CA. As you know, having an auto setting with A-SV and A/I-VAPS doesn't change why things are done.

https://www.scribd.com/document/35340282...-Titration (resmed link is down for the moment)
(bilevel spontaneous, timed)

Initial settings:
• IPAP = 8 cm H2O settings
• EPAP = 4 cm H2O
• Set backup rate at 2–4 below resting respiratory rate
Observe patient and document final pressure
settings (IPAP/EPAP pressures, respiratory rate and
TiControl settings) if altered from default

For obstructive apneas:
• Increase EPAP by ≥1 cm H2O every ≥5 min
• Increase IPAP to maintain 4 cm H2O difference between IPAP/EPAP

For residual snoring, hypopneas and/or O2 desats:
• Increase IPAP ≥1 cm H2O every ≥ 5 min until resolved

Evaluate and titrate: Note:
SpO2, VT and backup rate
should be reviewed/monitored
throughout the night.

• Based on VT (tidal volume), rate, SpO2 and CO2 compared to baseline
For SpO2 < 90% with all respiratory events eliminated:
• Increase IPAP by > 1 cm H2O every ≥15 min until SpO2 > 90% is reached
• Follow sleep lab protocol for adding O2

Evaluate VT (tidal volume) if too small:
• Maintain EPAP raise IPAP by 1 cm H2O every ≥15 min until SpO2 ≥ 90%
”Exploratory” pressure increase should not exceed 5 cm H2O (at a time)

Evaluate if backup rate is adequate:
• Increase backup rate by 1-2 BPM every 20 min as needed

[CTcentrals]

Igins: Just another note to let you know you're not alone and the problems can be overcome. I experienced similar, as TMoody, when I started years ago.  I would second DeepBreathing's suggestion about trying to breath deeply, slowly, and smoothly when you first put your mask on so the machine learns your rhythm.

Also, two things you might consider are 1) putting your mask on during the day/evening and just practicing your breathing to see how the pressure responds while you're awake and 2) maybe trying a different mask, too.  I started with the Quatro FX FFM and it didn't handle the pressure changes very well.  I use the Amara View now which works really well for me.