CPAP vrs APAP question

[Lori]

I hope you will forgive me if I'm asking a question that has already been answered. I have limited time here & have been reading as much as possible, but I am getting the distinct impression that an APAP may not be the way to go! I am wondering if on the Remstar CPAP if it always goes up to the setting it is set at every night or only if needed? Mine is set at 8 right now which often isn't enough. It always shows it being on 8 when I wake up. If it was reset to a higher number would the machine only go up that high if needed or does it automatically ramp up to the prescribed number? I am concerned about this "runaway" phenomenon with the APAP's and think I might be better off staying with the CPAP.
Thanks for any information,
~Lori

[littlebaddow]

Hello Lori, you haven't said which model you have.

The Remstar Plus and the Remstar Pro are CPAPs, ie fixed pressure machines that will only deliver a set pressure. These machines do have a ramp facility, which means that the machine will build up gradually to that pressure when first started, but it will never go above the set pressure and will stay there for the rest of the night.

The Remstar Auto is the APAP, which can be set to deliver a variable pressure depending on what it senses the user needs. For example, mine is set for a range of 6cm to 12cm, so when I turn it on I am getting the lowest setting of 6cm. When I go to sleep, the machine will increase the pressure if it senses that I need it, and then decrease it again and so on. It cannot, however, go above the limit of 12cm.

The Auto can also be set for a fixed fixed pressure, ie it can work the same way as a CPAP.

Many (though not all) people on this forum find the auto is a more comfortable experience, because generally it will be at a lower pressure for most of the night. In my case, the doctor prescribed a pressure of 11cm, but by using the auto I am usually spending most of the night at 6cm, 7cm or 8cm and still getting good treatment.

I am not a doctor, so you should talk to your own specialist, but I would urge you to try an auto machine unless your doc can give you a medical rwason why you shouldn't. Do remember, though, that many sleep specialists seem to favour CPAPs rather than APAPs for no apparent reason

Good luck

[neversleeps]

Lori-

Click on:

viewtopic.php?t=2473

Definitions.

[jdschooler]

Lori,

A machine that is in Fixed CPAP mode will always go to the setting it is set at whether you need more or less pressure. However, and AutoPAP uses a pressure range (mine is set at 8 minimum and 20 maximum). The machine will adjust itself between those two ranges based on what it senses is going on with your airway and breathing at that time.

I have not had any instance where is "ran away" and went higher than it needed to. However, I have had it reach the maximum setting (earlier my max was set at 14) and was no longer able to treat my apnea/hyponeas because it had reached its max. This resulted in increased apneas/hyponeas during that nights sleep and I ended up being fatigued for a couple of days, woke with Headaches due to hypoxia and Carbon Dioxide retention. So I increased my maximum to 20 and have never had a problem since then.

The nice things about APAP is that it only goes up as high as it needs to and that it senses when you are waking and lowers the pressure accordingly so you wake morcomfortably without that smothering feeling. I often wake up feeling like I am not wearing a mask or have air rushing into my airway that I don't need. These features also help reduce bloating caused by excessive pressure in your airway and inadvertantly swallowing the excess air. These machines also keep track of your apneas, hyponeas, AHI Index, Pressures used during multiple sleep sessions, and total time used. This allows you to be more in control orf your therapy and monitor your progress. I have found that my machine has kind of learned my sleep patterns and as a result I require less pressure now to maintain quality sleep.

Another feature alot of APAPs have is what is called C-Flex. This feature decreases the pressure during exhalation so that exhalation is made easier and more comfortable. My machine doesn't have this feature but it does sound inviting.

My APAP only gives me the pressure it senses is needed. A possible comlication is rain out (ccondensation in the supply tube) that accumulated in the lowest hanging part of the tube that can result in the machine sensing that more pressure is needed (and in fact more pressure is to get through the accumulated water) in order to control my airway. Simple solutions to this include: 1). decreasing the humidifier setting. 2). Applying a thermal sock (fleece fabric lining) to the outside of the tube to prevent cooling and condensation. or 3). Warming the room slightly to help reduce condensation in the tubing.

In summary, I love APAP and would never use straight CPAP unless I had to. But then again everyone is different with different physiological requirements so I am sure there are just as many people who prefer or need straight CPAP.

Hope this answered some of your questions and concerns. Good Luck.

[Guest]

Lori:

If you choose a straight CPAP machine, it will only ever function as a CPAP meaning that it can only deliver one pressure over the course of the night.

If you choose an AutoPAP machine, it will function in Auto mode, meaning that it will adjust pressure during the course of the night relative to your needs. Also, if you decide you do not like the Auto mode, you can easily set any of the AutoPAP machines to function in straight CPAP mode, meaning that it will deliver only one pressure all night.

AutoPAP can be pretty wonderful because it allows for lower overall pressures during the course of the night. I started with CPAP at a pressure of 15 and could not tolerate the chest pain and bloating that I had during the night and in the morning. I switched to an AutoPAP and find that the pressure for 90% of the night is around 9, and I periodically go up to a pressure of 11. This is a BIG difference in treatment and how I feel.


If you are concerned about runaway pressures with an AutoPAP, you could try the following:
1) Trial the different AutoPAP machines (ResMed Spirit [or software upgraded ResMed L7], Respironics RemStar Auto, and Puritan-Bennett GoodKnight 420E) to find the one(s) that seems to fit you the best BEFORE you bite the bullet and spend the money.

Although all of the AutoPAP machines are likely to work well for the user right out of the box, they do use different algorithms in their programming and, because of this, one of the machines might work better for you than the others.


2) Consider taking a good hard look at the Puritan-Bennett GoodKnight 420E as it is the only machine that allows some adjustment such that runaway pressure can be prevented.

Good-luck!

[WillSucceed]

Lori:

That last post was from me; I was not logged in.

[Lori]

Wow~thank you so much for the information. You have all been very informative & I am now rethinking the APAP vrs. CPAP. I was reading all the posts about the runaway pressures with the Auto Pap & that scared me a little. I do know I need a higher pressure & it would be nice to get a machine that would adjust accordingly without too much trouble. Thank you so much for the suggestions. They are very much appreciated. It is nice to have some information to carry with me when I finally do find a dr. here.
~Lori

[Newsgrouper]

Does the 90% number in the software data indicate that the pressure was at a certain level for 90% of the night or that the pressure was below that pressure for 90% of the night? I am confused (even by my own question)

[neversleeps]

Hi Newsgrouper,

Rested Gal answered this awhile back and I finally found the thread:
viewtopic.php?t=2752&start=0&postdays=0 ... ghlight=90

She's on page 1.

[rested gal]

Does the 90% number in the software data indicate that the
pressure was at a certain level for 90% of the night

No, it doesn't mean that. I'm not sure how to state it
precisely, but to me it means, "Your apneas and hypopneas were
taken care of (prevented and/or dealt with)
at THIS pressure (the "90%" pressure number)
AND pressures below it."

I'm unclear about whether "90%" means:

For 90% of the sleep session, or for 90% of the events
that were noted, or.... something else. LOL!!

The only thing I'm sure about is this: "90%" pressure
does not necessarily mean that that particular
single pressure was used 90% of the night.

In the Encore Pro software, just look at the table chart
of time spent at each pressure after one of your nights.
Most people see much, much more time spent at
pressures lower than whatever the "90%"
pressure number is for that one night.

My autopap is set for a range of 8 - 15. Often my
"90%" figure will be 10. But when I look at the table
chart, I'll see that over half the night (every night) is
spent down at 8. The remaining part of the night will
show much fewer minutes spent at various figures
above 8.

I think the reason software gives a "90%" figure (or in
the case of the Spirit, a "95%" figure) is to help a doctor
decide what single pressure to prescribe later for
straight cpap, if the autopap is being used for a one or
two week titration trial in the home.

oops, I was writing and didn't see your reply before I
posted, neversleeps. Thanks for the link! I'd forgotten
that.

My edit, over a year later (live and learn )

The 90th percentile pressure (or 95th, in the case of ResMed machines) refers to TIME -- 90% of the time, the machine had to use a pressure of, say, 12 OR pressures below that.

On page 8 of this topic:
viewtopic.php?t=10545

GoofyUT wrote:
It then reports the pressure that it operated at or LESS for 95% of the time for the session.

And -SWS wrote:
Just wanted to highlight this as the correct answer. Thanks for that much needed clarification.
_________________
-SWS