CPAPtalk.com

CPAP induced central events (rather than cardiac) can occur when the blood level of carbon dioxide drops below the apnea threshold. In other words if the CO2 drops too low, an apnea or hypopnea will occur. When this happens the CO2 levels rise rapidly but the body takes some time to respond and then overbreathing or hyperventilation occurs until the CO2 drops below threshold and the whole cycle can start again. Only some people have a potentially unstable breathing system and so most people are not prone to these (complex sleep apnea) events.

The link between EPR/CFLEX/AFLEX and these events is CPAP hyperventilation. It is likely that, once obstruction has been removed, it is CPAP induced hyperventilation which lowers the CO2 levels sufficiently to start the central apnea cycle in susceptible people. Lowering the pressure on exhalation tends to increase the volume of exhalation which in turn increases the volume of inhalation making hyperventilation more likely. This can be corrected by lowering, or preferably turning off, the exhalation relief if it is not too uncomfortable.

Sorry for the overly long explanation.
Ian

I'm the OP. I agree that I need to find a new sleep doctor, but that might take some time.

What if I can get one of my other doctors to write a prescription for a bipap? How would that doctor know what settings to prescribe? Do bipaps have an auto mode where the machine can figure out what settings to use?

Do most insurance companies require another sleep study before allowing a bipap? I don't mind the expense, but that wouldn't happen for at least another month and it might end up occurring on one of the nights where I have few apnea events. Thanks.

You would need to take a copy of your sleep study... Provide that to the new doctor and any other doctor.

I wish you good luck!

Do you mean give the doctor a copy of the sleep study that I had in October? That study doesn't indicate the need for a bipap machine --- do you think that would matter? I created reports that show the details of some of my bad nights; maybe they would be useful?

I think the more information you give the doctor the better. At least he will have the background information. No, I don't think it should matter. if you have the rest of the
detail to go with your logic for wanting bipap. I would think you should be OK.

Do you take any meds even OTC? If so, what are they ...dosage and time of dosage.
Have to ask...recreational drug use?

Can you provide a detailed SleepyHead nightly report for a good night and a bad night in terms of central events?
Don't need anything but AHI breakdown..events graph, leak graph, flow rate graph, flow limitation graph.
Don't need pressure or mask pressure graphs because your pressure is fixed.
Only need the basics.

Finally....give me AHI for last 2 weeks...overall AHI and hours slept for those nights. Be sure to mention how much of that AHI is central. Don't need total number of events if I know the hours slept.

Yes, you need a new doctor. I just thought maybe to do a little troubleshooting just in case we might stumble on to something that might help you while you are working on getting a new doctor.
No one should feel worse on cpap.....that's the bottom line
I don't know if bilevel machine would help or not. Depends on your insurance if you would need a new sleep study. Some will and some won't
I don't think that EPR is the cause of your centrals.
People shouldn't sleep 9 to 15 hours....something is wrong here.

When we have a good night on cpap and a bad night on cpap...makes it hard to figure out what changed because something changed to cause the bad night...something was different.
Complex Sleep Apnea (IF that is what you have going on here) isn't normally something that comes and goes willy nilly each night with having it one night and not having it another and normally takes more than 5 centrals per hour to buy the diagnosis.

I appreciate everyone's responses. I'll try to post graphs and answer questions tomorrow.

I'm the OP with an update.

I switched sleep doctors last week. My new one was willing to look at my detailed data that showed all the central apnea events, oxygen, and pulse data. (My previous sleep doctor said I was doing great just because my monthly AHI was around 3. She didn't take into account how much worse I was feeling and wouldn't look at any of the detailed data I faxed. I maintain that an average AHI is pretty useless when you have large variances from night to night like I do. Some nights are .1 and some are over 8.)

My new doctor ordered oxygen for while I sleep (nights and naps.) He said to use the oxygen without the cpap for a month and then see him again. At that time, he might order another sleep study to try an ASV. The great news is that I'm finally beginning to feel a bit better after suffering terribly for over 3 months.

Ironically, the sleep doctor I quit is a neurologist board certified in sleep medicine in the Sleep Disorder department at a very prestigious medical center that probably everyone in the USA has heard of. It's several states away and I have to fly there. I've been going there for years because my local neurologist originally referred me because he'd never seen sleep problems like mine. It turned out i have a very rare sleep disorder that I probably couldn't have gotten diagnosed by many other places in the world. My latest sleep study there revealed sleep apnea which is why I started on the cpap. (I also have other rare medical conditions/diseases so I see a variety of specialists there. I'll continue to see the other specialists for those problems.)

Thanks for all the advice! I pray that I continue to improve and regain more quality of life.