ResMed Definitions Please

[vkmaynard]

What are the ResMed Auto 25 Definitions for settings like Support Pressure, TI Max, Rise Time? What are "normal" results?

I have a copy of ResScan 5.7 and a ACR38U reader.

My sleep lab AHI was 35 with Predominately Central Apneas. Recommended pressures of 14/9.

Had the machine for < week with AHI of 20. No sleep still. Tried both auto and spontaneous. Breath time to short/fast set TI Max to 1.4 and the Rise time to 350 ms.

Use a Swift LT Mask.

Not super overweight (BMI 24), don't snore, low BP (110/70) and in good shape. Too many Hang glider, Kiteboarding, Snowboarding and car accidents I guess.

DO NOT WANT TO BE ON A MACHINE!

Thanks

[jnk]

What are the ResMed Auto 25 Definitions for settings like Support Pressure, TI Max, Rise Time? What are "normal" results?

I have a copy of ResScan 5.7 and a ACR38U reader.

My sleep lab AHI was 35 with Predominately Central Apneas. Recommended pressures of 14/9.

Had the machine for < week with AHI of 20. No sleep still. Tried both auto and spontaneous. Breath time to short/fast set TI Max to 1.4 and the Rise time to 350 ms.

Use a Swift LT Mask.

Not super overweight (BMI 24), don't snore, low BP (110/70) and in good shape. Too many Hang glider, Kiteboarding, Snowboarding and car accidents I guess.

DO NOT WANT TO BE ON A MACHINE!

Thanks

Pressure support is the difference between inhale pressure and exhale pressure. (Your Rx, according to what you typed, seems to be for 5, since 14 minus 9 is 5.)
TiMax is the maximum amount of time you get to cause an exhale before the machine drops to exhale pressure for you.
Rise time is how long it takes to get up to inhale pressure. That setting doesn't matter when Easy-Breathe is engaged in auto mode.
"Normal" is a slippery concept. The default TiMax is 3 seconds on that machine, I think. No need to play with it unless the machine is getting out of sync with you. Rise time in spontaneous mode is often considered to be basically a comfort adjustment for people with vanilla OSA with no complications.

How is your leak?
Are you able to get AI below 1.O most nights?

You will want to be on the machine once you get your PAP therapy going and are successful with it. The difference it will make in how you feel will make you love your machine like a family member. You will never want to go back.

If you have mostly central events, you may not want to fiddle too much with your settings. It may be they are seeing how you do on bilevel before moving on to a machine designed specifically for treating the various forms of central sleep apnea.

In the meantime, if it was me, I would set up my machine with a pressure support of 5, a max IPAP of 14 and a min EPAP of 9 in auto mode. That will keep the machine from moving the pressures at all, keeping it at exactly what the doc prescribed. I would leave Ti Max at the default. I would see what that did for my numbers for a few weeks before doing anything else. But, hey, that's just me.

jeff

[Slinky]

I second jnk's suggestion to set your VPAP Auto 25 at your scripted IPAP 14, EPAP 9 and Pressure Support 5 and VPAP (auto) mode. I have the Auto 25's immedicate predecessor, the VPAP Auto, and that is the way I used mine: IPAP 12, EPAP 7, Pressure Support 5 and VPAP (auto) mode. To h*ll w/Spontaneous mode, too doggone many "comfort settings" to figure out to get comfortable with. I've not had any success in Spontaneous mode and LOVE my VPAP Auto in auto mode w/the Pressure Support set properly at the difference between IPAP and EPAP.

[Guest]

Why would I not leave the IPAP and EPAP at their min and max values and let the auto mode figure out (14/9)? What does "hardwiring" the numbers do for you in auto mode? If I "hardwire" the numbers why does the machine need me to do the math and set the Pressure Support to 5?

Ti Max default is 1 and Ti Min default is 0.3. Again, why would you not "max out" the numbers and let the auto mode figure it out?

I notice that when I quit breathing (centrals) the machine quits breathing in both modes. That does not seem very helpful.

Spontaneous mode is very uncomfortable. It adds an additional drop or puff that keeps me awake. I've tried setting the TI Max and Rise Times to fix this problem. 14/9 keeps me awake so I don't believe the sleep lab when they set me up with Ambian for the test (makes centrals worse I believe). I set the ramp to 35 min to no avail. I gave up altogether last night on the machine just to get some sleep.

Thanks,

Victor

[Slinky]

Yep, in Spontaneous mode the Rise Time, Ti Max and Ti Min are trickly little buzzards to pin down for some of us.

I was originally titrated for my bi-level on Respironics lab equipment and they came up w/IPAP 13, EPAP 8. No recommendation on my script for Pressure Support. When I got my VPAP Auto it was set up by my DME provider at IPAP 13, EPAP 8 and Pressure Support 4 and in Auto mode. That left a little play for the pressures. 2.4 cms either way. I did pretty good w/it in Auto mode until at 3 months or so my sleep doctor switched me to Spontaneous mode. I ran into the same thing you are running into. None of the locals I've encountered are familiar enough w/the Resmed bi-level autos to know how to set them correctly so I was in Spontaneous mode w/the default Rise Time, Ti Max, Ti Min, etc. Everything Default except the IPAP and EPAP in Spontaneous mode. The Conversion charts between the Resmeds and Respironics aren't very good according to one of the manufacturer reps I talked to.

So, with some experimenting and some advice from a couple of sleep professionals, I went back to Auto mode and kept the Pressure Support set at the difference between IPAP and EPAP. That makes it run as a straight bi-level in Auto mode. And it is SMOOTH, EASY BREATHING. COMFORTABLE!

When I am next re-titrated on a bi-level I am only going to agree to having the re-titration done on Resmed lab equipment. I spoke to our local Resmed Rep (I've made him and Resmed aware of the abrupt transition in pressure in Spontaneous mode - there are 17 of us I've found who have this problem). He has offered, and my local sleep lab agreed, that when we next do a bi-level re-titration he will bring Resmed lab equipment and will remain thru the night's titration. Those of us who have switched to Auto mode w/the PS set to the difference between IPAP and EPAP are happy as pigs in a pile of dung w/our VPAP Autos and Auto 25s set up this way.

If you had a lot of centrals during your in-lab sleep evaluation (not titration) it may well be that you should be on the Resmed Adapt SV ENHANCED.

[jnk]

Turns out we're both wrong on the defaults. I just checked the manual for that machine (what my lazy butt should have done before I replied before, sorry) and it says the default Ti Max is two seconds and the default Ti Min is 0.5 seconds.

Here are some definitions from ResMed:

IPAP is the pressure which will be delivered to the patient when the VPAP is triggered into inspiration.
EPAP is the pressure which will be delivered to the patient when the VPAP is cycled into expiration.
Pressure Support Difference between IPAP and EPAP in VAuto mode. Adjust for patient comfort.
Max IPAP Sets the maximum inspiratory pressure delivered by the device.
Min EPAP Sets the minimum expiratory pressure delivered by the device.
Rise Time The Rise Time scale can be approximately read as ‘milliseconds’ (eg, 200 is approximately 200 ms).

Ti Max Sets the maximum limit on the time the VPAP spends in IPAP.
Ti Min Sets the minimum limit on the time the VPAP spends in IPAP.

[frostyref]

Wow, You all have been so helpful. I also was titrated originally on respironics equipment. About 2 weeks ago, that old box just up and died, and it forced me to get something else. Since I moved, the local provider reps the ResMed equipment. The first night the new ResMed was set to Spont. I played with the Timax and Timin, and the response time, but to no avail. The thing just didn't seem to provide enough air at the right time. and even at the best I could adjust it, when I breathed in, the high pressure would turn off and switch to low pressure when I was only half way through a breath. and the abrupt pressure drop between low and high was extremely disruptive. It took me about 90 minutes to finally drift off, and my wife told me that I needed to do something different because I snored through the mask all night. Nice. I am going to change to auto mode and set the pressure support to the difference between my Ipap and my Epap. I hope and pray that it works like you all claim. thanks for the help!

[Slinky]

Let us know how it works out for you, FrostyRef.

[rested gal]

the abrupt pressure drop between low and high was extremely disruptive.

If it were me, I'd set the TiMax to as much time as it would allow... I'd set it at 3.0 (3 seconds.)

That doesn't mean the higher IPAP pressure will stay in place no matter what. If you start to breathe out during the 3 seconds, the machine will switch immediately to the lower EPAP pressure. It won't keep blowing the IPAP pressure for 3 whole seconds of inhaling, just because it's allowed to.

Even setting it to allow 3 full seconds for inhaling (TiMax) might not keep it from making you feel that your inhalation was being cut off abruptly. If you occasionally take a long, slow "sighing" type of inhalation that goes on for longer than 3 seconds, the IPAP pressure will be cut off at the 3 second mark and the lower EPAP pressure will happen. Most people don't breathe in for that long at a time regularly.

As far as I know, all bilevels have a max amount of time IPAP can be delivered before they switch down to a lower EPAP.

[Slinky]

In Spontaneous mode it felt to me like the VPAP thought I wasn't inhaling long enough so hurried up and gave me one last good "puff" at 12 cms BEFORE dropping to my EPAP of 7.