Potential for iVaps mode to help with UARS

[mintjberry]

Has anyone looked at machines that can do iVaps? They are pretty much a ventilator. From my understanding you set inhale/exhale pressures, target breathing rate per minute, and volume. The machine will ensure your breathing matches these settings. Differs from the usual BiPAP where you have to actually start to draw in air before the machine will boost your pressure up.
My Resmed machine has been modified with an unlocked ROM (AirBreak) which enables all these options for me.

I have had a lot of issues in trying to fully treat UARS. I'm keen to try something else, and the iVaps mode may be worth a shot. I should add that I think I'm a very shallow breather, at least during the day. I'm a 6' tall male but my tidal volume is often only in the mid 400s, so hoping the iVaps mode can help bring that up.

[Sleeprider]

With UARS tidal volume may be affected, but the real issue is time of inspiration is relatively long reflecting respiratory effort. Tidal volume alone is not a good measure of the airway proficiency, and if you want any further opinion on that, post some Oscar charts. Personally, I think iVAPS would be a tremendous waste of resources for inspiratory flow resistance and would guide you to consider the Aircurve 10 Vauto instead.

[mintjberry]

So I slept last night with iVaps. Settings:
Height: 185cm
Target Pt Rate: 14.0, I dropped this to 13.0 in the middle of the night when I woke as the inhale/exhale frequency was a bit high. I think I'll lower this to 12 tonight.
EPAP: 5
Min PS: 4
Max PS: 9

AHI of 0

My average tidal volume was up to 540 over the course of the night. I probably only got about 6 hours sleep. Last night was the first night in as long as I remember that I've not needed to use the toilet in the middle of the night, and didn't even need to go when I woke. No other modes have done this, and I've experimented a heck of a lot with different CPAP pressures and BiPAP pressure ranges. In the past I've found that lower exhale pressures (under 6.6) would cause me to wake up at least twice in the night to use the toilet, but I'd sleep for a good 8 hours and brain fog slowly got worse. Higher exhale pressures would mean I'd only need to get up once to use the toilet, but I would wake up early, often only getting 5-6 hours of sleep, which was exhausting on the body, but the brain fog wasn't quite as bad.

I feel OK, not markedly better but I only got 6 hours sleep so I don't expect miracles. The brain fog certainly isn't any worse than yesterday, probably a bit better.

[cmpman1974]

I have an Air Curve ST-A on IVAPS mode.  So far, I have not enjoyed the experience.  Mine was not prescribed for the reason you want one though. You have very low pressure settings though for IVAPS I think. I have not heard of anyone using that machine for your issue. Was it prescribed by a sleep specialist?

[mintjberry]

Nope I flashed a ROM which enables (almost) full functionality on my Resmed Autoset 10. I have since pushed up the EPAP.

[Sleeprider]

I think you would do better on Vauto mode. UARS generally responds to pressure support once the airway is stabilized with sufficient EPAP. I assume you have no need for the backup rate or ventilator capability. With an Airbreak machine you won't get trigger sensitivity settings that can also help.

[mintjberry]

I think you would do better on Vauto mode. UARS generally responds to pressure support once the airway is stabilized with sufficient EPAP. I assume you have no need for the backup rate or ventilator capability.  With an Airbreak machine you won't get trigger sensitivity settings that can also help.

I tried BiPAP for years. High pressure, low pressure, high pressure support, low pressure support. Nothing helped me like iVAPS is. I don't know why but the results speak for themselves, at least in my case.

[Sleeprider]

I missed the fun of your previous misadventures, so I'll take your word for it. In fact, I haven't seen any Oscar charts of your therapy on iVAPS. Maybe we should change that. I don't mean to judge if you have already proven my assumption wrong. I thought your were asking if iVAPS would help. Show me.

[mintjberry]

While Oscar can be immensely useful, it doesn't come close to telling the full story on sleep quality, especially with UARS.
What's more important is: How are your energy, stress, anxiety levels? How bad is your brain fog? How long are you sleeping at night, and are you waking for seemingly no reason? Did you need to use the toilet in the night? How are you performing at work?

I don't need to prove it to anyone and I'm not trying to convince anyone, I'm just reporting what has helped me. I'm definitely not 100% yet, but I'm much better than before.

[StuartC]

I am late to this party but I would like to comment on some of the things you have said about iVAPS

"The machine will ensure your breathing matches these settings. Differs from the usual BiPAP where you have to actually start to draw in air before the machine will boost your pressure up."

Like S/T mode, the iVAPS will only step in if your RR drops too low.  The idea is that you set your Target Patient Rate (TPR) to the rate you do or should normally breath at.  ResMed seem to like 15, for example.  At that TPR, your RR can drop right down to 10.1 and the machine will not intervene, it will let you continue to trigger inspiration spontaneously.  But as  soon as your RR hits 10 (two thirds of the set TPR) or lower, it will start to trigger non-spontaneously.  Over the course of the next 4 or 5 breaths, the trigger will happen at an increasing respiratory rate until it is triggering at a rate of 15 (the TPR set).  This will continue indefinitely until you trigger inspiration spontaneously sooner than it triggers non-spontaneously.

"So I slept last night with iVaps. Settings:

Height: 185cm
Target Pt Rate: 14.0, I dropped this to 13.0 in the middle of the night when I woke as the inhale/exhale frequency was a bit high. I think I'll lower this to 12 tonight.
EPAP: 5
Min PS: 4
Max PS: 9"

You missed a key setting, alveolar volume (Va), which can then be converted into equivalent minute vent (Mv), tidal volume (Vt) and tidal volume per kg ideal body weight (Vt/kg).  So if your tidal volume rose to 540 ml, then presumably Va was set somewhere in the region of 5.5L.  More useful though is that your Vt/kg would have been about 7 ml/kg, which is, I think, quite a common and reasonable target.

It is good to keep an eye on your median pressure value and your time at pressure chart.  If iVAPS is working as intended, your median should be somewhere between IPAP min and IPAP max so it has ability to adjust both up and down to compensate for both high and low volumes.  On the time at pressure chart, the peak value should typically be somewhere in  the middle of the IPAP range, not all the way at either end.

Another thing you can monitor is your Spont. Trigger and Spont. Cycle values found just above the bottom of the sleep report on your machine, and nowhere else. Remember to set the sleep report period to 1 day.  I am not working from any formal knowledge of what these should be, but I work on the assumption that the higher the better.  Of course, spont. cycle, in particular, can be "fudged" by extending Ti Max, so perhaps it is spont. trigger that tells you the most.  Think for yourself what they mean relative to your therapy.