[Equipment] Resmed ST-A with IVAPS comfort/smoothness

[ntntnt58]

When it comes to smoothness, how does ST-A with IVAPS compare to ASV? I completely understand they are different machines for different purposes, but how do they compare in terms of how smoothly the machine is breathing with you? Is it like the regular Bi-PAP with square and unnatural breaths or is it more like ASV, but with a set target tidal volume instead of 90% target tidal volume? I've been on ASV for 5 years with good results, but my tidal volume often slowly falls bellow normal and wakes me up. It's 100% psychological, caused by PTSD/anxiety/shallow breathing and I have it when I'm awake as well. Increasing the pressure helps, but obviously makes it more difficult to sleep, so I want to try the IVAPS.

Thanks for your help.

[ajack]

They treat different things and aren't really interchangeable. I'd go back and talk to your Doctor. Was the ASV prescribed for you in a sleep study?

If you want to put up a oscar chart of your ASV, you will get some opinions on that.

[ntntnt58]

My doctor has been very unhelpful. He did say he would prescribe IVAPS for out of pocket purchase, but before I spend thousands on it, I just need to know if it's as rough as a typical BIPAP machine, which I can't tolerate, or if it's a smooth as an ASV. I understand they are not interchangeable, but I have a very unique condition that makes me hypoventilate.

My ideal tidal volume is 354ml (6ml/kg * 59kg ideal body weight). 

Here is the graph before I increased the pressures. I frequently had tidal volume slowly fall into mid 200's and sometimes lower for extended periods of time, anywhere from minutes to almost an hour. Or I had minute vent fall into lower 3's because my respiration rate falls into 7's and 8's. After raising the pressures and playing with settings a bit, my VT is much higher, but it still falls sometimes and stays around 300. My MV also still falls into mid to lower 3's sometimes because of low RR.

(Ignore the hypopneas as they happened when I was awake and ignore the median and 95% VT as it is offset by me breathing deeply before falling as asleep. My AHI is usually 0 or close to it.)

   

[ntntnt58]

I noticed there is a leak in my graph, that is not an issue, here is my MV falling down to 3 without any major leaks.

   

Also, yes my ASV was prescribed from a sleep study. I was prescribed a backup rate, but I couldn't tolerate the Respironics machine, so I got Resmed instead, it says it has an unadjustable backup rate of 15, but obviously that's not working for me.

[ajack]

I would put the smoothness aside, you will get use to whatever machine will treat you. ivaps are more like bpap than asv. The backup breaths and pressure rises are also slower to come in, was the main thing I noticed on vaps. Sprinter to a jogger comparison.

TSVanwinkle had a similar chart, to your's at 3:00. Where the tidal volume, minute vent and resp. rate fell, while there was still high PS. In his case raising epap and PS made it worse. I think the issue is that the resmed will cycle down to around 8 breaths per minute. Before I swapped modes to vaps, That won't treat the CA as good. I would try ther philips with an adjustable back up rate, but you may also need a higher starting PS. depending on copay, you might want another titration.
http://www.apneaboard.com/forums/Thread-...-into-this

I sent him a message, he may post and say where he is on his path. You could also message him

[Sleeprider]

Your Resmed S9 Adapt (ASV) and the newer Aircurve 10 ASV provides a flow smoothing algorithm called EasyBreathe™. This flow smoothing is not available in the ST model and I am unsure about iVAPS. Usually people are issued ASV for complex or central apnea that requires a backup for IPAP that can trigger a breath when you don't spontaneously breathe. iVAPS can theoretically fulfill this function, and also targets aveolar volume to maintain tidal volume.

On your S9 Adapt, you are using ASVauto mode with EPAP min of 6.0, EPAP max 8.0, and PSmin 2.0, PSmax 15.0. If you want to target tidal volume with your current machine, increase PSmin. Your results look pretty good on ASV, and I would be reluctant to change therapy devices without knowing more. You can look at the intended uses for iVAPS and they tend to be used to target pulmonary and neuromuscular disease and hypoventilation, rather than complex apnea.

[ntntnt58]

Your Resmed S9 Adapt (ASV) and the newer Aircurve 10 ASV provides a flow smoothing algorithm called EasyBreathe™. This flow smoothing is not available in the ST model and I am unsure about iVAPS.  Usually people are issued ASV for complex or central apnea that requires a backup for IPAP that can trigger a breath when you don't spontaneously breathe.  iVAPS can theoretically fulfill this function, and also targets aveolar volume to maintain tidal volume.

On your S9 Adapt, you are using ASVauto mode with EPAP min of 6.0, EPAP max 8.0, and PSmin 2.0, PSmax 15.0.  If you want to target tidal volume with your current machine, increase PSmin.  Your results look pretty good on ASV, and I would be reluctant to change therapy devices without knowing more. You can look at the intended uses for iVAPS and they tend to be used to target pulmonary and neuromuscular disease and hypoventilation, rather than complex apnea.

My EPAP/PSmin were 6/2 before I increased the pressure. I first tried 10/2 which helped, then 8/6, which helped some more but lowered my RR too much, so I narrowed it down to 9/5. I've read about IVAPS/AVAPS and how they are used for COPD and other disease, but I do have hypoventilation. My MV falls as much as 30% bellow minimum as my RR falls down to 7's and 8's on regular basis. What should someone do if they have both a complex sleep apnea and hypoventilation?

[Sleeprider]

Using the ASV, EPAP controls for obstruction. PSmin is the minimum pressure support, and as that is increased, so is tidal volume. So if you are at EPAP 6.0 and PS min 2.0 that means the machine will provide at lease 8.0/6.0 (IPAP/EPAP) pressure. By increasing PSmin, for example to 4.0, we could make that 10.0/6.0 and increase Vt. PSmax is always on standby if your volume falls into flow limitation or hypopnea realm or if a CA occurs, so if a CA event occurs, your machine could produce 21/6 (PS 15.0). The ASV titration protocol decision tree follows. Your comment was using some pressure notation that does not seem correct.

[ntntnt58]

Using the ASV, EPAP controls for obstruction. PSmin is the minimum pressure support, and as that is increased, so is tidal volume.  So if you are at EPAP 6.0 and PS min 2.0 that means the machine will provide at lease 8.0/6.0 (IPAP/EPAP) pressure.  By increasing PSmin, for example to 4.0, we could make that 10.0/6.0 and increase Vt.  PSmax is always on standby if your volume falls into flow limitation or hypopnea realm or if a CA occurs, so if a CA event occurs, your machine could produce 21/6 (PS 15.0).  The ASV titration protocol decision tree follows. Your comment was using some pressure notation that does not seem correct.

No, I'm saying I've already increased my PSmin from 2 to 5 and it did help my VT, but my respiration rate is still around 8, which leaves my MV too low at times. My current pressure is 9 EPAP (needed for OSA) and pressure support is from 5 to 15. The problem is the ASV machine only supports a target ventilation of 90% over the last few minutes. So when my ventilation falls abruptly, it works fine, but when my ventilation falls slowly over time, it can't do anything, I just keep breathing less and less.

[ajack]

I think you have the issue well understood. You originally had the philips, that you didn't like at the time. That has an adjustable backup rate and may resolve the issue for you. In the end it may be the best machine for you.

If it were me, I'd contact resmed tech department and ask their opinion. You could email your chart. They would be the ones, I would talk to. I don't think a doctor would have the depth of understanding, on how these machines work and rely on the labs to get it right.

Resmed
For Customer Assistance including Technical and Patient Support:

1 (800) 424-0737 (toll-free) in United States and Canada

Technical Support: Monday to Friday, 5:30am - 5pm PT.

Patient Support: Monday to Friday, 6:00am - 3pm PT.