CPAP vs. APAP

[erik67]

Have been watching these boards silently for some time, and am finally beginning to post. My question is at the bottom of this post, but Here's my story if you're interested:

I've been a CPAP user for about 1 1/2 years now, and have tried over a dozen masks (not kidding - my DME says that I hold the record in their clinic). I am determined to make this treatment work, as I find the alternative of getting the back of my throat ripped out to be a bit drastic.

Anyway, I have had the most success with the Resmed Mirage Activa, but have recently begun to feel very tired. My Doc thinks that the mask is leaking, and she upped my pressure from 7 to 9 and had the RT fit the mask more snugly to my face. Well, definitely no leaks now, but the mask is leaving red marks on the bridge of my nose.

As an Engineer by trade and a bit of a tech geek, I was intrigued to discover that there is a machine (APAP) out there which will actually tell you if your mask is leaking, adjust the pressure automatically, and has software (!) so that you can monitor nightly performance/compliance.

So here's my question: If I don't start feeling more rested again at the higher pressure, do you think that it's worth asking the Doc about an APAP? Has anyone else had this type of experience? Do I have it all wrong about the APAP?

I am also planning on changing to the ComfortLite 2. The things I hated about the first one (already tried it) seem to have been improved in the new version; and most folks on the boards seem to like it.

Thanks for any info you can provide.

Erik

[Guest]

There are also cpap machines that can give you treatment data, it doesn't have to be an apap.

[tooly125]

my first question would be are you sure your not leaking pressure out of your mouth?
Ever wake up with a dry mouth?

[erik67]

I'm pretty sure that I'm not leaking out of my mouth. The only time I wake in the AM with a sore throat is when I don't use CPAP. In fact, it's almost impossible for me to talk or breathe out of my mouth when I have the mask on.

[MandoJohnny]

I asked my doc about APAP. He said that it is no more effective than CPAP for Obstructive Apnea, although it may help some people with compliance. It doesn't sound like you have compliance problems. He said APAP is mostly useful for Central Apnea and some other complications, like hypoventilation. I don't think the primary idea behind the APAP design is to adjust for leaks.

I have a straight CPAP, but it monitors leaks. I can get a leak readout every morning. I think the idea is to see if you have leaks and correct them, not compensate for them with different pressures.

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CPAPopedia Keywords Contained In This Post (Click For Definition): CPAP, APAP

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CPAPopedia Keywords Contained In This Post (Click For Definition): CPAP, APAP

[roztom]

The APAP may allow you to run at lower initial pressure and in theory the machine, depending on alogarithm will respond to events or pre-evenjts like snore or flow limitation by raising pressure.

The assumption being that the machine will bump pressure higher until it clears the event or reaches its programed limit.

For some this seems to work well, for others a fixed pressure seems to work better. It's really a matter of your personal sleep architecture.

This is not a complete explanation by any means.

Being able to monitor your therapy and see what is happening is key to getting the best treatment.

There has been much discussion about CPAP vs APAP. Do a search - there is a wealth of info .

Best,

Tom

[IZATIRED2]

My sleep techs told me at my titration sleep study that if I got tested every night for a week the pressure would be different every night. That was enough reason for me to get an APAP. I just received one 4 days ago from cpap.com and so far I think it was worth the extra money. Also if you change masks from say UMFF to Swift nasal the pressure required for the nasal is 1 to 2 cmh2o less to get the same AHI redings.

I just got my hybrid today. Hope it works!

[orange-man]

After having just switched to an APAP after 2 years with CPAP, the APAP is much better for me. The reason is that my CPAP was set for 14 and in reading the APAP data I spend nearly all of the night in the 8-10 range with momentary jumps up to 12. Less pressure means almost no leaks and not disruptions and just a more pleasant experience all the way around. I feel so much better.

Your mileage may vary but my take on the APAP vs. CPAP is that the sleep study people feel obligated to pick a pressure that will never fail (which is the right thing to do) but he APAP lets you sleep with a lot less pressure only bumping up when you need it.

[dsm]

<snip>
He said APAP is mostly useful for Central Apnea and some other complications, like hypoventilation.
<snip>

Hi MandoJ,

The above snippet is an interesting theme for discussion.

There is a strong case that says that AUTOs are not ideal for treating Central apnea. Most AUTO algorithms, if they conclude a Central is occurring, will do nothing or will lower cms. They usually don't try to increase cms.

BiLevels are generally the better device for centrals but only those BiLevels that have some kind of timed control or detect zero airflow - they typically will then flip from EPAP (Exhale) to IPAP (Inhale) in the expectation the sudden change will get the person breathing spontaneously again. Some controlled BiLevels repeat this flip every 4 seconds while the airflow is stopped.

AUTOs were designed to make compliance easier (the greatest reason why people give up on xPAP therapy is because of the discomfort from higher pressures which in turn will create problems in getting a good mask / mouth sealing). But because of their sophistication they also had better data recording & reporting & thus became very popular just for that capability alone. It is highly debatable that AUTOs are better than straight CPAP when it comes to minimising APNEA events but AUTOs do improve compliance statistics as they keep the average cms lower which in turn reduces the mask/mouth problems that so many of us grapple with.

If the Central is however, a pressure induced one then backing off cms is a good strategy. IIRC Pressure induced centrals can occur as a result of cms being to high for a particular type of breathing pattern. This can cause the person to slow/stop breathing & thus in this particular pattern, the treatment creates a new problem for the user.

Speak for myself. when ever I travel I switch to a straight CPAP machine & generally get by very well. I have access to AUTOs that I could use but apart from the great statistical data they provide, I for my own therapy, stick to BiLevels (by far the best pressure relief) & CPAPs for travel.

Cheers

DSM

[mister_hose]

Hi, I'm new here, first post. Hi guys! I've been on CPAP for half a week now, and am adjusting fairly decently.

One possible reason CPAP might sometimes be preferable to APAP is when dealing with "fast-onset" apneas. During my second sleep study, the technician told me the next morning that I'd been on both CPAP and APAP during the night (standard sleep study practice to try them both), and that while on APAP I had had several fast-onset apneas that caused me to awaken (seriously enough that I remembered those awakenings in the morning!) because "the machine couldn't compensate fast enough to prevent them". That's all he said, but presumably since CPAP is constant pressure, it would've prevented these fast-onset apneas, and the associated awakenings, while APAP could not.

Just a thought. Of course, there's other reasons CPAP can be preferable to APAP too, even when money is no object (quickly-changing pressures arousing or waking the patient, etc.)

Me, I have a Respironics M-Series REMstar Pro with the M-Series heated humidifier. This is a good unit for me since it's CPAP (and thus can prevent those fast-onset apneas that APAP can't) and yet it has the same advanced data collection features as an APAP, plus C-Flex for a vaguely BiPAP-like pressure reduction on exhale. An ideal machine all around, for my needs.

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CPAPopedia Keywords Contained In This Post (Click For Definition): respironics, bipap, humidifier, C-FLEX, CPAP, APAP

[rested gal]

During my second sleep study, the technician told me the next morning that I'd been on both CPAP and APAP during the night (standard sleep study practice to try them both)

That's very interesting. I'd never heard that trying both CPAP and APAP are standard sleep study practice during PSG titrations. Trying CPAP and then switching to trying bi-level in certain circumstances during a titration, yes...but I'd not heard anyone else say their sleep study including trying APAP as "standard practice". Not that that would be a bad thing to try...I just hadn't heard others say APAP was tried during their sleep study unless they had gone in for another titration using their own machine.

"the machine couldn't compensate fast enough to prevent them". That's all he said, but presumably since CPAP is constant pressure, it would've prevented these fast-onset apneas, and the associated awakenings, while APAP could not.

If an APAP is left set wide open (4-20) as seems to be the custom of most health care professionals who give out an APAP at all, yes, I can see where sudden onset apneas could be ahead of what the machine can do in the way of "prevention." I think most people who read the message board understand that the range each person uses with an autopap should be tailored to their needs. For some (me, and probably you, mister-hose) setting the low end of an autopap's pressure range up pretty close to what a single prescribed effective pressure would be can work better, smoother. Others can use a lower "low" and do fine.

Setting the low pressure near, or at, prescribed pressure would seem to negate buying an autopap. If a person were going to set the low pressure that way (I do), that's almost like using straight cpap. So why get an autopap? Why go to the extra expense? To my way of thinking, I like having a cushion above... setting the maximum pressure as a ceiling with some room under it, in case "more" is needed occasionally during the night, or on some random nights.

Whatever range a person uses with an autopap, I would be surprised if 4-20 suits them as well as a low pressure closer to their prescribed pressure would. Just because autopaps are designed to be able to use 4 - 20, it doesn't mean that range should be used for everyone on autopap.

Just a thought. Of course, there's other reasons CPAP can be preferable to APAP too, even when money is no object

True. A single pressure (whether you get if from a cpap machine or an autopap working in cpap mode) does suit some people better. APAP suits others better. Many people do get effective treatment from a single straight pressure. It's a good thing there are plenty of choices of machines out there. And masks.

One of the very nice things, imho, about an autopap vs a straight cpap machine is that the autopap mode of operation can ALWAYS be turned off....the autopap can be set to work in straight cpap mode, if a person needs or prefers a single pressure. Can't go the other way with a straight cpap machine.

Me, I have a Respironics M-Series REMstar Pro with the M-Series heated humidifier. This is a good unit for me since it's CPAP (and thus can prevent those fast-onset apneas that APAP can't) and yet it has the same advanced data collection features as an APAP, plus C-Flex for a vaguely BiPAP-like pressure reduction on exhale. An ideal machine all around, for my needs.

You have a very good machine, indeed. It's always great to hear that someone has a machine that they're happy with and are getting good treatment with. Meeting our treatment needs is what it's all about. If I were going to use a straight cpap machine, the one you have (Respironics M series Pro) is the one I'd want, too.

[dsm]

Re using both APAP & CPAP in a sleep study. That seems unusual to me & the 1st time I have heard this.

Would be interested to know whereabouts this clinic was.

I go along with RG's comments on this.

Cheers

DSM