The problem seems to be that your machine is recording a fair number of CAs. And CAs don't usually disappear by increasing the pressure and increased pressure can make them worse.
Have the CAs been in the machine recorded data ever since you started CPAP/APAP? Or are they new?
About 10-15% of new PAPers do develop some problems with CAs after starting therapy. But for most of these people, the CAs will disappear on their own after a few weeks to a couple of months of therapy. In other words, for most of these people, the CAs disappear after the body fully adjusts to PAP therapy and the brain is no longer struggling to figure out how to maintain the correct CO2 level in the presence of the slightly pressurized air.
But you've been PAPing for quite a while. So if the CAs were present right from the start, it would be reasonable to assume that if they were going to disappear on their own, they probably would be substantially lower than they currently are. So it's good that you are planning on seeing the sleep doc in the near future to address what's going on.
Quote:What are the basic differences between these machines (with some technical info)? And which machine type might be the right option (or best next step) to help my apneas?
1. PR REMstar Pro C-Flex+ System One. This is the machine I was started with last fall in "Auto-Trial" mode, the purpose they clearly told me was to ascertain the optimal pressure to use when I was switched to CPAP (which occurred after 3 mo's).
The Auto-Trial mode for the System One pro is a "time-limited" APAP. There's a maximum length of time the machine can be run in APAP mode and after that it switches (or is switched) to straight CPAP mode. When the machine is in Auto-Trial mode, it is running as a full fledged APAP. The only difference between the System One PRO and the System One AUTO is that the Auto can run in APAP mode for as long as you own the machine.
Both the System One PRO and the System One AUTO are typically used to treat plain old OSA. Both have a Flex system to provide exhalation relief. Sometimes the Flex setting can have an affect on a person's tendency to develop CAs. How the Flex does this varies from person to person. So if Flex is set to 2 or 3 and you're getting a fair number of CAs, you can try turning Flex down or off. Conversely if Flex is off or set to 1 or 2, you can try turning the Flex up.
Quote:2. "BiPAP" - At the last visit the tech suggested this type of machine would help CA's. So I'll be asking about this.
Technically speaking BiPAPs are not specifically designed to treat CAs. But they're substantially cheaper than the ASV machines. Many insurance companies will require an unsuccessful trial on BiPAP or BiPAP auto before moving a patient to an ASV machine.
A simple BiPAP (or Resmed VPAP) runs in what is called "S" mode. It increases the pressure to the IPAP pressure at the beginning of each inhalation and decreases it to the EPAP pressure at the beginning of each exhalation. The IPAP and EPAP pressures are fixed and the difference between IPAP and EPAP can be set to be anywhere between 1cm and 6-8cm (or more). The most typical IPAP-EPAP spread is about 3-5cm. An Auto BiPAP allows the IPAP and EPAP pressures to vary in response to events. PR Auto BiPAPs allow the IPAP and EPAP pressures to vary independently of each other; Resmed Auto VPAPs increase and decrease the IPAP and EPAP together so the IPAP-EPAP difference remains constant.
Some people who have problems with pressure-induced CAs do find that their CAs disappear when switched to BiPAP/VPAP. The pressure relief created by the drop to EPAP can make it easier to fully exhale and that in turn can make it easier for the body to properly maintain the nighttime CO2 levels where they need to be to trigger nice regular sleep breathing. And it's this fact that underlies the usual insurance company's insistence on a BiPAP/VPAP trial before authorizing a switch to ASV.
Quote:3. APAP - For example the AirSense 10 AutoSet (as I've read).
The Resmed AirSense 10 AutoSet is just the newest Resmed version of the PR System One Auto CPAP. The newest PR APAP is the PR DreamStation Auto CPAP by the way.
In theory the AirSense 10 AutoSet can't do anything in Auto mode that your old PR System One Pro couldn't do when it was running in Auto-Trial mode except, of course, run in Auto mode for an unlimited amount of time.
In other words, all an APAP does is allow you to run in Auto mode for the entire time you own the machine. Or switch to fixed pressure mode and run in CPAP mode if you want. So APAPs are a bit more flexible that straight CPAPs.
But it's also important to understand that there are some differences between the Auto algorithms for the AirSense 10 AutoSet and the PR Auto CPAPs. Which is best for your particular situation can be a very tough question to answer since most people don't have a chance to do a head-to-head comparison. The presumption made by most sleep docs is that both algorithms ought to be about equally effective (in terms of treating OSA) and equally comfortable. They also assume that most patients probably won't be able to tell any difference between the two machines.
ASV machines are very expensive and they tend to be used to treat primary central sleep apnea
problems as well as treating complex sleep apnea
in patients who continue to have significant numbers of pressure induced CAs after several weeks or months of CPAP, APAP, BiPAP (VPAP), and/or Auto BiPAP(VPAP) therapy. In other words, they're typically used when all else fails.
ASV machines can (and do) act as noninvasive ventilators in a way that CPAPs, APAPs, and BiPAPs do not. An ASV machine can attempt to "trigger" an inhalation when you have not inhaled on your own for a specified amount of time. An ASV machine can also monitor the tidal volume of your breathing and it may also trigger inhalations if your breathing becomes too shallow to maintain a proper CO2 level. The ASV "triggers" an inhalation by drastically increasing just the IPAP at fixed time intervals when no inhalation (or an insufficient inhalation) occurs. The BiPAP (VPAP) machines do not increase the pressure to IPAP until an inhalation is detected.
ASV machines are often used to treat CSR since CSR can result in long chains of CAs, which occur at the nadir of the breathing cycle.
Quote:I've also learned that insurance may only want to move to APAP if CPAP isn't working. Maybe they'll keep me on the CPAP.
The insurance code for CPAP and APAP machines is the same thing. So if your doc were to write a script for APAP, there's a good chance the DME would just swap the current CPAP out for an APAP from the same manufacturer. (How your copays would work depend on your insurance company, the DME, and whether the machine is sold on a "rent to own" contract or was sold outright.)
Most insurance companies will want some kind of documented evidence for switching a patient from CPAP/APAP to bilevel (BiPAP or VPAP). What that documented evidence is may depend on the insurance company. The insurance company or the sleep doc may insist on a new titration study before switching a patient from CPAP/APAP to bilevel.
In my case, my sleep doc wrote a one page memo saying the following:
- I had tried CPAP and APAP (same Resmed S9 AutoSet) at several different pressures,
- I had tried more than one mask style,
- I was still experiencing severe aerophagia in spite of the changes to therapy,
- I was using the machine at least 4 hours every night with low machine reported AHIs,
- and I was unable to function in the daytime due to sleep deprivation in spite of using the machine every night as prescribed.
After that, the insurance company authorized a bilevel titration study and after that study, they were willing to pay for the bilevel machine that I now use.