[Treatment] CO2 and Central Apneas

[dscbk]

Admin thread warning to new CPAP patients: This thread contains information concerning CPAP mask modifications which may be dangerous if attempted without seeking professional help from a qualified sleep doctor. Disclaimer: Patients are free to do as they wish, however Apnea Board does not condone these types of inherently risky mask modifications. Thanks.

Have read through many of the threads but have not seen much discussion on CO2, triggers and central apneas.

I had two sleep studies done. First one showed AHI of 35, 50/50 CAs/OAs. Second one was for titration on the CPAP. Recommendation was for 9cm. I got a new cpap machine Respironics System One I think it is called, used it for a week or two and had the rep read the SD card. OAs came down a bit, but CAs not reduced. Rep sent data to Dr. who prescribed a Bipap at 14/10 settings. Got one, used it a week or two and had rep read the SD card. OAs down as before, but CAs not reduced.

I began a little research on CAs. Found they often start and/or increase with use of cpap. Although they can be related to heart trouble, basic mechanism for breathing/not breathing i.e. CA is CO2 concentration in the blood; if too high, triggers breathing response. If too low, no breathing response i.e. CAs. Read several research studies done on adding CO2 mixtures into face masks and in adding “dead space” to a mask to increase breathing residence time in the mask thereby increasing CO2 concentrations and it directly affects CAs.

So my theory is: even though the cpap/bipap machine controls pressure at settings, the flow rate of air thru the mask is controlled by the amount of openings in the mask. The more openings, the higher the air flow required to maintain the pressure settings. With higher flows, the O2 concentrations and saturations are high which is desirable, but it also reduces the CO2 perhaps below the threshold/trigger point for breathing in particularly sensitive individuals. This may explain why cpap use causes/increases CAs in some people.

I began my own research by closing off certain openings and controlling the remaining openings to slow down flow rate but keep pressure settings, thereby lowering O2 and increasing CO2. I was aware of going too far and getting into trouble, but have been able to survive and see on my SD card data that the CAs came down below 5, OAs controlling around 5 also based on pressures. I'm still tweaking settings trying to get good readings and be comfortable. I have a Dr. appt. in a week and will discuss (and I’m sure get reprimanded) but has anyone else got any info on this ? Thanks for any ideas and suggestions.

Dscbk

[greatunclebill]

welcome to the forum.

it looks like you've done your research and believe in what you're doing so i won't tell you it's a bad idea to tamper with mask ouflow for a million different reasons. you'll probably get your well deserved reprimand next week by a more knowledgeable person. good luck.

[zonk]

Good luck with the doctor appointment.
What is your leak, high leak can affect the measurement.
What are you tampering with? Vents holes designed to flush out exhaled air and the anti-asphyxia valve on full face mask to allows you breathe room air if power goes out for any reason otherwise you might suffocate.

SleepyHead software is free and support PRS1.

[dscbk]

I'll have to check leak rate numbers, but am pretty able to notice when it is leaking somewhere.

Yes, I'm blocking the vent ports and anti-asphyxia valve but leave an open nasal port open. This reduces the high flow rate through the mask but still leaves a small flow rate/anti asphyxia port to build up CO2 concentration.

That leads to my next question: is there an XPAP machine that hooks an O2 sat sensor into the machine and records it on the data card with the rest of the data ? That is what I really need to make sure I'm not reaching dangerous CO2 levels.


Thanks for any info.

[dscbk]

My average leak rate with the high CAs was around 37. With the ports partially blocked and lower CAs it is between 5 and 7.

[archangle]

This does need to be said before someone else tries it and kills himself.

Blocking off any holes on your CPAP mask is a really bad idea. Death could result.

Yes, you could conceivably do it right and not die. Maybe even improve your therapy. If you miscalculate or do it wrong, you could die.

Oxygen deprivation is particulary dangerous because you can become unconscious without any warning signs. Healthy, fully awake adults can lose consciousness and die without ever noticing anything is wrong. Google "confined space training" to get an idea about how dangerous this is in industrial environments.

[jdireton]

You are the owner of your treatment and I respect that.

The Resmed 9 series does have an optional O2 sat module/sensor that integrates into a data port on the back of the machine. The Rescan software will report these numbers, don't know about Sleepyhead.

CPAP's calculate leaks based on what the expected flow rate through the reliefs would be for your pressure, so masking off relief vents will invalidate the leak info from your machine. You may think your leak is better but are just "tricking" the reading.

I agree with archangel, you're going into dangerous territory. If you're oxygen deprived, even well before death, you get very impaired and may be too affected to even realize it before bad things happen.

Hypercapnia is nothing to ignore either.

Best of luck with your results!

[SuperSleeper]

This does need to be said before someone else tries it and kills himself.

Blocking off any holes on your CPAP mask is a really bad idea. Death could result.

Yes, you could conceivably do it right and not die. Maybe even improve your therapy. If you miscalculate or do it wrong, you could die.

Oxygen deprivation is particulary dangerous because you can become unconscious without any warning signs. Healthy, fully awake adults can lose consciousness and die without ever noticing anything is wrong. Google "confined space training" to get an idea about how dangerous this is in industrial environments.

I'm quoting the above for emphasis because I want everyone on this thread TO READ IT, please!

[dscbk]

Got the message loud and clear ! I appreciate your concerns, the issue, your ideas and suggestions. Thanks.

[SuperSleeper]

Got the message loud and clear ! I appreciate your concerns, the issue, your ideas and suggestions. Thanks.

Good luck, dscbk... didn't want to come off sounding overly heavy-handed, but there are risks involved here as I know you're aware. Just wanted to make sure a newbie doesn't come strolling through thinking that's it's perfectly okay to block mask ports.

Thanks.