Cpap/Bipap

[vlad2075]

Can someone explain the difference?

I'm having issues maintaining a stable AHI level. I currently have a Philips Dreamstation that from what I understand has the ability to do bipap as well.

Thanks!

[Pugsy]

First let's figure out exactly what machine you have.
Look on the bottom for the model number which will start with DSX and followed by 3 numbers then some letters which don't really matter.
It's the 3 digits that matter the most.

Cpap...continuous positive airway pressure....single pressure (not counting any exhale relief)
apap...auto adjusting positive airway pressure...still a single pressure (not counting any exhale relief) but it the pressure can auto adjust

Bipap is Respironics term for a bilevel pressure machine
Bilevel pressures are 2 distinct pressures (not counting any exhale relief) with one for inhale and one for exhale...these can be either fixed or auto adjusting.

What is your AHI and what is the event category breakdown of that AHI?

The machine you have chosen in your profile right now is the DreamStation Pro...it's a fixed cpap machine with limited apap mode available.
It does NOT have bilevel/bipap capabilities.

[vlad2075]

Yes I just checked and it is strictly a CPAP device. I did see I have a tear in my hose and just ordered a new one from Amazon.

My AHI is .7 one day to 9.6 the next, then down to 5.5. It's really all over the place.

Does the tear in the hose have anything to do with it? Does bumping up the pressure help?

[Pugsy]

I don't know if the tear has anything to do with it but it sure isn't helping. You can tape it with something like duct tape until the new hose arrives. If it is a big tear then the machine can't compensate for it and you won't be getting the pressure you might need...so the leak has to be fixed. Machines can compensate for small leaks but not torn hoses.

To evaluate your AHI we need to know what that AHI is made up of because if it s mainly OAs and hyponeas then more pressure is needed but if mainly ClearAirway/Central events the more pressure won't help and could make things worse.

So before you go changing anything you need to figure out what you are fighting.

The information on the LCD screen is limited.
There's a lot more detailed information available using the software.
https://sleep.tnet.com/equipment
For some examples of what you can see
viewtopic/t103468/Need-help-with-screen-shots.html

First thing though...fix the hose.

[vlad2075]

It's definitely OA's and hyponeas. Very little clearway apneas.

For example, last night I had 20 OA's and 25 hypopneas, 1 clearway apnea is 8 hours 13 minutes of sleep

[Pugsy]

If the hose was torn last night then it is entirely possible that enough air pressure leaked out the hose and the machine wasn't able to maintain sufficient therapy to prevent those events.

You can use the software and see just how bad the leak might have been.

What did the LCD screen show for leak reporting?

[vlad2075]

Well it showed a 100% mask fit

[Pugsy]

100% means if you were leaking it sure wasn't much. 100 % means no leaks into large leak territory. Also means we can trust the data reported.

You probably need more pressure at some point in the night for whatever reason and not other points. I suggest that you get the software up and running and see what is going on.

When we have nights where the pressure seems to work fine and the AHI is nice and low and then the next night the AHI isn't so nice and low we have to wonder "what changed".....why is the pressure fine for one night and not another.
Obviously something changed. My first thought is the person is sleeping more on their back on the "bad AHI" night.
It's common for some people to have their OSA be worse when they are on their backs and even need more pressure when on their backs.
Same thing can happen with REM stage sleep.

When you use a fixed pressure machine like yours the machine can't go higher...assuming it needed to.

This is why it is helpful to see the detailed reports. If there's some significant dense clustering of OAs/Hyponeas then we have to think of either supine sleeping or REM.

[Pugsy]

the machine tries to bump pressure to make up for it

.

No...actually it doesn't. When faced with really large leak the machine will actually back off a bit on the pressure in hopes of letting the mask settle back down and get the seal back.

Besides...the machine is showing 100% perfect mask fit...no large leak flagging at all.

[ajack]

leaks can affect results

the machine tries to bump pressure to make up for it
you should not be changing the pressure to try to outthink the machine as it would then try to give you the wrong pressure

with a leak, the machine increases flow to try and maintain the same pressure.