Configuring an AVAPS

[jbsix]

Hi guys,

I've been on CPAP for about 8 months (mainly OSA's and hypopneas) with decent results (AHI 3.5-6.5) but have been having trouble exhaling with any pressure above 10 even with maximum A-flex.

I had a single trial run with an auto bipap (set to auto) and this resulted in no OSA's but a ridiculous amount of CSA's. Reading on these forums, this is probably complex/mixed apnea and only avaps will solve this.

So before I make a ridiculously expensive purchase I was hoping for some input:

1. Since the above trial was a "titration study" and was pretty much just setting an auto bipap to auto, I was wondering if manipulating the I/E-PAP range better could result in more realistic CSA's and thus a less expensive purchase of an auto-bipap.
For e.g. on CPAP, my settings are 8-12 mmh2o so if I tried ipap 8-12 and epap 8-10 would i see 'normal' csa's?

2. I would prefer to set up an AVAPS (if needed) without my doctor (since the above was his idea of a titration study). How would I go about doing this?

[Crimson Nape]

The CA's could be from CO2 washout. Without any supporting data posted anyone, including me, would be just guessing at this point.

You can use this link to help you prepare the SleepyHead data:
http://www.apneaboard.com/wiki/index.php...ganization

Help for posting charts here:
http://www.apneaboard.com/wiki/index.php...pnea_Board

[Sleeprider]

Don't jump the gun on concluding those CAs are anything to do with complex apnea. What is your pressure support set to? If your machine has variable PS, keep PSmax to 3 or less and try again.

[jbsix]

Since the bipap was not mine and used for the "titration study", i only have the encore viewer report the tech sent me.

Bipap Auto titration:


a good night on cpap (auto 8-12; ahi 4.71)


an ok night on cpap (auto 8-12; ahi 5.81)


a horrible night on cpap (auto 8-12, ahi 10.55)

What is your pressure support set to? If your machine has variable PS, keep PSmax to 3 or less and try again.

If you mean the flex, on my apap i've tried everything from 1-3. On the bipap it was "avg flex 2.0" according to the report. I don't have the machine, nor can I obtain one without paying full price

[Sleeprider]

That is a more complete picture. Pressure support is the difference between EPAP and IPAP in cm-H2O on bilevel machines. With some CPAPs we may consider the IPAP-EPAP difference to be pressure support, but it is considered a comfort feature and called X-Flex or EPR depending on the brand.

More to the point, you have enough events that it may be diagnosed as complex apnea. I dunno. That is going to require a sleep study with CPAP, bilevel and ASV and a doctor's opinion.

I think if you are diagnosed with complex apnea, the recommendation will be for an adaptive servo ventilator (ASV) rather than AVAPS, which is usually for problems related to physical restriction, pulmonary disease or obesity hypoventilation. Many members here us ASV machines and can help you if that is the case.

[jbsix]

More to the point, you have enough events that it may be diagnosed as complex apnea. I dunno. That is going to require a sleep study with CPAP, bilevel and ASV and a doctor's opinion.

I'm sorry, I thought I'd mentioned this in my OP:

The doctor said "you should get a bipap with st mode or even avaps if you can."

But, there were several red flags with this guy that gave me the impression that his evaluation was biased towards whatever he stood to make from me purchasing the machine(s) from "his guy" (philips rep).

Anyhow, I'm trying to avoid buying the bipap-st, ending up with csa's and then having to buy the avaps as well. I'm also trying to fill in that missing "here's your machine- now this is what you do with it" step, which i subsequently ignore, mangle and tweak to get the best results.

EDIT:
Also,
1. His diagnosis was central sleep apnea despite everything.
2. seeing AVAPS and ASV in the same sentence, I'm no longer sure which one I was told to get. The prescription only says bipap st...

[Sleeprider]

I'm confident you would be better served by an ASV solution. Get a real doctor, not an equipment rep. Next question is your cost insured, or is this out of pocket?

[jbsix]

I'm confident you would be better served by an ASV solution. Get a real doctor, not an equipment rep. Next question is your cost insured, or is this out of pocket?

That was pulmunologist/sleep specialist #5 and by far the best experience. Now you understand why I'm fed up and going it alone. No insurance; all out of pocket.

I've been reading up on ASV and it does look like the better solution for complex apnea. Thank you so much for your input!

[jbsix]

Doing some research and several sources say that ASV has the same features as ST machines but uses better algorithms. However looking through the PR System One AutoSV Advanced Manual, I don't see any settings describing backup rate, spontaneous, timed or anything else.

How does one configure ASV's defining features?

[Sleeprider]

The other unit to look at is the Resmed Aircurve 10 ASV. For the System One SV advanced, the backup rate is called BPM or breaths per minute. By default, I'd suggest 14, but you may be able to look at your CPAP data and get something about 2-BPM less than your normal mean. The setup is pretty simple. This device offers up to 25 cm maximum pressure. You can set the max not to exceed any pressure, but for you, probably 20 cm. EPAPmin and needs to be set high enough to prevent most OA. For you, I think EPAPmin 8.0 and EPAPmax 11.0. PSmin 2.0, PSmax 8.0.

With these settings you will start at 10/8.0 to 13/11 for normal spontaneous breathing, and will see up to 16/8.0 to 19/11 in the presense of CA. The machine will detect reductions in volume and insufficient breaths per minute and will provide pressure support on a breath by breath basis to maintain your respiratory volume and rate.

Other settings have to do with inspiration time, BiFlex or rise time, ramp, humidity etc. The PRS1 960P is a full automatic ASV and has many settings that can be tweaked to increase comfort and synchronization with your breathing. An optional heated hose is available for this unit for about $75, and you can add it at any time.