How does CPAP work? Doesn't make sense

New to CPAP actually BiPAP in my case, can't sleep at nite because of the mask setup waking me up. How can sleep be better, if I'm waking up more?
Anyway, feels like I can't breathe while using the mask, done some calculating, seems the tidal lung volume of healthy adults is around .5 liter. My hose & mask volume of air is around .3 liter. If I'm simply pushing air back & fourth through a hose, that has over half the volume as I'm breathing in, I'm getting less than half the air I would normally get, without the mask/hose assembly, attached to my face. Seems this is almost like breathing into a bag? What am I missing here??

MRRPM wrote:New to CPAP actually BiPAP in my case, can't sleep at nite because of the mask setup waking me up. How can sleep be better, if I'm waking up more?
Anyway, feels like I can't breathe while using the mask, done some calculating, seems the tidal lung volume of healthy adults is around .5 liter. My hose & mask volume of air is around .3 liter. If I'm simply pushing air back & fourth through a hose, that has over half the volume as I'm breathing in, I'm getting less than half the air I would normally get, without the mask/hose assembly, attached to my face. Seems this is almost like breathing into a bag? What am I missing here??

Hi MRRPM,

Welcome to the forum.

As an fyi, the problems you are experiencing are quite normal for a newcomer. You have come to the right place for help. But first, we need you to fill out your equipment profile so advice can be targeted particularly to your situation. Please use the link in my signature to do that.

Hopefully, you have a data capable machine that lets you access data in which you would be able to post screen shots that would enable forum members to assist you in optimizing your therapy. One thing I am wondering since you said you can't breath with the mask is whether your minimum pressure is set too low. So if you could include what that is in the comments, that would also be helpful.

Hang in there, we'll help you through this.

49er

Thanks, but my machine isn't listed in the choices.
It says Phillips Respironics Bi-ap Pro and Bi-Flex on the top, system one at the bottom, as does the humidifier.
It does have an SD card in the back, never put it in my computer, what software do I need to read the data on it?

MRRPM wrote:Thanks, but my machine isn't listed in the choices.
It says Phillips Respironics Bi-ap Pro and Bi-Flex on the top, system one at the bottom, as does the humidifier.
It does have an SD card in the back, never put it in my computer, what software do I need to read the data on it?

If you turn over your machine, does it say model 650/660? If the answer is yes, you can download Sleepyhead Software, which is free.

http://sourceforge.net/projects/sleepyhead/files/

You need a data card reader and a USB cable so the information can be transferred from the card to the installed Sleepyhead Software.

49er

On the bottom, it says REF 660p, no mention of any model.
My computer has a card reader in the side, so all I need is software to read the data. I'll download & install that software & see if it'll read the files.

MRRPM wrote:On the bottom, it says REF 660p, no mention of any model.
My computer has a card reader in the side, so all I need is software to read the data. I'll download & install that software & see if it'll read the files.

You're good to go.

Here is a tutorial that one of our forum members, Pugsy, wrote, in case you're interested in deepening your understanding of Sleepyhead. Of course, feel free to continue to post any questions you have that you would like other forum members to respond to.

viewtopic/t88983/Pugsys-PointersSleepyH ... nding.html

49er

To answer your guestion as copied in below.

"It seems the tidal lung volume of healthy adults is around .5 liter. My hose & mask volume of air is around .3 liter. If I'm simply pushing air back & fourth through a hose, that has over half the volume as I'm breathing in, I'm getting less than half the air I would normally get, without the mask/hose assembly, attached to my face. Seems this is almost like breathing into a bag? What am I missing here??"

What you are missing is that there is a "bypass" built in that clears (vents) the the hose and mask of exhaled air of each cycle before you inhale, so you are breathing new air and not rebreathing your old air.

Welcome to the forum.

Your equipment is indeed available in the drop down menu.
This would be what you would choose for your machine
PR System One 60 Series Bipap Pro with BiFlex
and this is the humidifier you would choose
PR System One 60 Series Heated tube humidifier with heated tube
You may not have the heated tube (long hose) but that's your only choice for humidifier. The heated hose is an option. If you are unsure whether you have the heated hose or not...the heated hose has a black end on the end that connects to the humidifier.

I am very familiar with the model 660 and the 760 as I have both models. Great machines.
I know it seems far fetched but we do get to where we sleep better with the machine than we do without them. It's hard at first because we aren't used to having the mask on and air going up our nose.

Let's figure out what might be keeping you from sleeping.
Issues breathing? Feeling suffocated?
Issues with the mask?...leaks, pain..whatever?
Are you having trouble falling asleep...staying asleep or both?
Did you have any of these issues sleeping well prior to cpap therapy?

rkuntz123 wrote:To answer your guestion as copied in below.

"It seems the tidal lung volume of healthy adults is around .5 liter. My hose & mask volume of air is around .3 liter. If I'm simply pushing air back & fourth through a hose, that has over half the volume as I'm breathing in, I'm getting less than half the air I would normally get, without the mask/hose assembly, attached to my face. Seems this is almost like breathing into a bag? What am I missing here??"

What you are missing is that there is a "bypass" built in that clears (vents) the the hose and mask of exhaled air of each cycle before you inhale, so you are breathing new air and not rebreathing your old air.

Ok, I think I understand what you mean, meaning there is a check valve that allows air to go out, but not come in (from outside). If so, my mask has no such valve. Even if it did, the PAP machine would simply open said valve, when it makes pressure.

MRRPM wrote:

rkuntz123 wrote: Ok, I think I understand what you mean, meaning there is a check valve that allows air to go out, but not come in (from outside). If so, my mask has no such valve. Even if it did, the PAP machine would simply open said valve, when it makes pressure.

MRRPM...
Exhaust is through a small hole...not really a valve. Next time you have your mask on with machine running, simply move your hand around the mask until you feel the air blowing. That's where the CO2 is exhausted.

If you do not have any air blowing out from your mask, I'd say you have a problem with your mask. It could be plugged or a manufacturing flaw. If no air blowing...call DME for a new mask.
J

Pugsy wrote:Welcome to the forum.

Your equipment is indeed available in the drop down menu.
This would be what you would choose for your machine
PR System One 60 Series Bipap Pro with BiFlex
and this is the humidifier you would choose
PR System One 60 Series Heated tube humidifier with heated tube
You may not have the heated tube (long hose) but that's your only choice for humidifier. The heated hose is an option. If you are unsure whether you have the heated hose or not...the heated hose has a black end on the end that connects to the humidifier.

I am very familiar with the model 660 and the 760 as I have both models. Great machines.
I know it seems far fetched but we do get to where we sleep better with the machine than we do without them. It's hard at first because we aren't used to having the mask on and air going up our nose.

Let's figure out what might be keeping you from sleeping.
Issues breathing? Feeling suffocated?
Issues with the mask?...leaks, pain..whatever?
Are you having trouble falling asleep...staying asleep or both?
Did you have any of these issues sleeping well prior to cpap therapy?

As far as machine, I selected the one you mentioned, seems kinda Klingon as far as jargon in madical devices. In industrial equipment, you simply look for model & serial.

I don't know what's keeping me from sleeping, I feel as if I can't get my breath, took mask off, all is good, I go to sleep.
No pain, can't tell if it's leaking or not, I fall asleep almost immediately, wakeup in a few hours.
When I had the sleep study, they said I had 20 something episodes per hour, on my back, and 6/hour on my side. I think it was per hour, maybe per minute, don't remember. The reason I was sent for a sleep study, I had chronic A-Fib, & my doctor wanted me to go for a sleep study. I underwent RF ablation, haven't been in A-Fib since, & it's been three months, & they're slowly weaning me off the meds.

MRRPM wrote:I don't know what's keeping me from sleeping, I feel as if I can't get my breath, took mask off, all is good, I go to sleep.

What are your pressure settings?
Are you using the ramp feature..if so for how long and what starting pressures?

jamiswolf wrote:

MRRPM wrote: MRRPM...
Exhaust is through a small hole...not really a valve. Next time you have your mask on with machine running, simply move your hand around the mask until you feel the air blowing. That's where the CO2 is exhausted.

If you do not have any air blowing out from your mask, I'd say you have a problem with your mask. It could be plugged or a manufacturing flaw. If no air blowing...call DME for a new mask.
J

There is a series of holes around the periphy of the hole where the hose plugs in. Yes, no valve, air comes out, CO2, and all the other gasses we exhale, along with fresh, humidified air, from the machine. As small as these holes are, there is no way that all the air that I'm exhaling will go through them, in the time it takes me to exhale, so some, (who knows how much) is going back up the tube to be rebreathed. That's not much of a problem, since the air we exhale is not completely scrubbed of O2, the air can be rebreathed, to a point. If all I'm doing is rebreathing that mostly rebreathed air, I will eventually run low of O2, no matter how many breaths I take.

Welcome MRRPM!

I was new to this CPap stuff, I started in April 30 of this year.

To help you understand what is happening to you I would recommend you take the time to review this Video
http://www.resmed.com/us/multimedia/und ... 40x380.swf

This put things in perspective for me.

Learning to sleep with the mask is tough but worth your effort. I wish you good luck.

MRRPM wrote: As small as these holes are, there is no way that all the air that I'm exhaling will go through them, in the time it takes me to exhale, so some, (who knows how much) is going back up the tube to be rebreathed. That's not much of a problem, since the air we exhale is not completely scrubbed of O2, the air can be rebreathed, to a point. If all I'm doing is rebreathing that mostly rebreathed air, I will eventually run low of O2, no matter how many breaths I take.

MRRPM,
You're confusing your perceptions with science. These machines and masks are designed by engineers with advanced degrees and of course, CO2 exhausting would be thoroughly investigated. I totally understand your feelings since I had the same problem when I first started. I even went so far as to drill the exhaust holes larger on the nasal mask I was using.

The biggest issue with the feeling of suffocating that many experience is low pressures. Many people have difficulty with pressures below 6 cm or so. Also, perhaps you would do better with a full face mask. When I switched to the Quattro FFM, many of my mask issues disappeared.
Good luck to you...
Jamis