many centrals on therapy. none in the overnight studies

[urbanscribe]

confused.

been on the machine (auto set S9) for 10 days
OA have been crushed down to low levels but Centrals are stubbornly present
two overnight in-home sleep studies showed no Centrals at all
can the therapy be causing centrals? are these centrals indicative of other problems?
could they be misinterpreted?

[JDS74]

Yep.
It's called pressure induced central apnea or "Complex Apnea."

You will need a sleep lab titration and perhaps a change to an ASV machine.

At this point it is critical to decide if you are comfortable with the pressure algorithms of the S9. This is a feeling issue not an efficacy of treatment issue.

If you are having problems on how it feels, you may want to consider switching to a Respironics machine which can feel different. Not many people can feel the difference so you may not.

If that is the case, keep with ResMed. Their ASV is excellent as well.

[kaiasgram]

urbanscribe, how many centrals are you talking about? The images you posted are not active links.

[LSAT]

Almost everyone gets some centrals....if your centrals are 1-2 an hour there is no problem. If you have dozens in clusters, there may be a concern. Get specific...what is your AHI and how many are centrals.

[Slartybartfast]

You might look up Hering-Breuer reflex. http://medical-dictionary.thefreedictio ... r+reflexes

The "centrals" aren't real, in that they're not caused by the central nervous system telling the diaphragm not to inflate the lungs. Rather, what you're describing is an artifact of CPAP therapy. The lungs are kept inflated to some extent by the positive pressure in your airway. Stretch receptors in the lungs block the diaphragm from inflating the lungs because they're already somewhat inflated. So your machine records it as a Central because it doesn't know any better. It should be called an open airway apnea, or non-obstructive apnea, because the machine doesn't know what your central nervous system is doing unless it's reading the tension in your diaphragm muscles to make the determination. So it's not really a Central. It's just a reflex action caused by the therapy.

When titrating a patient in the sleep lab, the tech should adjust the pressure until the obstructive apneas just cease, but not raise the pressure so high that the HB reflex starts to manifest itself.



All that aside, it's likely that you're a little more sensitive to pressure than most people. If you were running straight CPAP, it would be a simple matter to simply reduce the pressure a half cm or so and see if that helps. But you're running an autoPAP. The algorithms that determine how the machine responds to the cues it receives from your breathing patterns aren't perfect. Some machines are better than others, and differences among individuals sometimes mean that one machine might not work as well as another for you. Evidently the machine that was used for your in-home overnight study performed better for you than your S9 Autoset.

[urbanscribe]

thanks for the answers

as for data, can you all not see the attached images which show the centrals (clear airway As), their distribution as well as all the daily AHIs?
i can retype them but they are all on the 3 graphs above.

if i am missing something which sleepyhead outputs please let me know what to post

[urbanscribe]

slarty great explanation and great chart
indeed i am waking up with aerophagia plenty
interesting

[robysue]

You might look up Hering-Breuer reflex. http://medical-dictionary.thefreedictio ... r+reflexes

Slartybartfast, thanks for this fascinating link!

[kaiasgram]

thanks for the answers

as for data, can you all not see the attached images which show the centrals (clear airway As), their distribution as well as all the daily AHIs?
i can retype them but they are all on the 3 graphs above.

if i am missing something which sleepyhead outputs please let me know what to post

All I'm seeing is this -- there are no active links to your graphs:

[palerider]

thanks for the answers

as for data, can you all not see the attached images which show the centrals (clear airway As), their distribution as well as all the daily AHIs?
i can retype them but they are all on the 3 graphs above.

if i am missing something which sleepyhead outputs please let me know what to post

you did the links incorrectly, next time, try using the 'preview' to see how your post will look before you hit 'submit'

[kaiasgram]

JDS (see post above) has instructions in his signature box on how to take a screenshot, upload to a photo site, copy the "Image" code, and paste the code into your post. If you're on a Mac I have info on taking a screenshot below in my signature box.

[palerider]

JDS (see post above) has instructions in his signature box on how to take a screenshot, upload to a photo site, copy the "Image" code, and paste the code into your post. If you're on a Mac I have info on taking a screenshot below in my signature box.

if you're using sleepyhead, just press f12 (don't know how that translates to macspeak though)

[urbanscribe]

thanks

i actually uploaded the screenshots to dropbox and then verified in preview they were appearing before posting.
anyway, i moved them to another hoster, see above.

[tortoisegirl]

I also had centrals emerge with CPAP, and it happened at home since I didn't have a lab titration. I assume you didn't have a titration since you said home study, but there were two? I only started with mild apnea so my AHI was initially almost as much as pre-CPAP, mostly due to centrals. I started on APAP, pretty wide open. I had a follow up after a week. My doctor said that the amount of centrals I was getting was something to keep a close eye on, and if after some pressure adjustment, if the centrals remained above 5/hour on average, then a BiLevel or ASV would be indicated. If I was getting 20/hour then she would have been concerned and scheduled a lab titration right away.

I also complained of feeling like the pressure changes were disrupting my sleep. She thought tightening the pressure range on the APAP would help that, and changed it from 4-14 to 7-12. I was sleeping worse and my AHI increased more. I knew it would take awhile to get an appointment, so I decided to try one night of a low constant pressure (5), to at least know if it was the pressure changes that were bothering me. I had a great night sleep and my AHI went down to 2. Needless to say I have kept it around that pressure. So I guess I'm one of those folks who need very little pressure. That pressure is enough to prevent most of the obstructive events, and keep the centrals to a minimum. Average AHI is now 3 using a pressure of 4.8.

I guess I could try even lower, but then it doesn't seem like enough air. I had a follow up a month later and my doctor said she doesn't usually like patients changing settings, but she was glad things changed around so well and so quickly for me. I think my tweaking saved a lot of time and frustrations, vs. having a pressure adjustment then going back weeks later. By the way in APAP mode it had been going up to a pressure of 9, yet when using CPAP, I get a better AHI with 5. I have also found that on a typical night I have a few centrals register while I am still awake, before falling asleep (it only takes a 10 second pause to register one).

How soon is your follow up after starting CPAP? If its not for awhile, can you move it earlier? Ideally you should work with your doctor to see if like Slartybartfast said, there is a pressure or pressure range which prevents most of the obstructive events but keeps centrals to a minimum. From what I know the centrals don't seem to be in a large enough number to cause panic, but action is needed, or at least monitoring. At this point with an average of 3.83 centrals/hour, you likely wouldn't meet your insurance's guidelines to try ASV. Its also possible that the centrals will decrease over the next couple weeks, or that not all of these are real centrals (especially if you are spending a significant amount of time awake with the mask on). If you aren't able to see your doctor soon or such, I'm sure the folks here can help you try to tweak the settings. Good luck! Best wishes.

[urbanscribe]

thanks tortoise girl

indeed no titration study, and honestly no medical direction as my GP is the one who wrote the scrip for 6-20. not spending much time with the mask before falling asleep.

following is really interesting

By the way in APAP mode it had been going up to a pressure of 9, yet when using CPAP, I get a better AHI with 5.

i will have to try either a tighter band (bringing down the top end) or cpap as you have.

i am not expecting any follow up to be honest. my gp is not properly informed for any of this and not trusting my DME with much more than providing masks and checking compliance for the insurance company. have thought about paying for a titration study (insurance has declined) but thinking that all this data may prove more useful in finding the ultimate solution.

worried about the continued existence of centrals/clear airways although NONE were apparent in the sleep studies (as mentioned). don't want to just be pushed to VPAP without some real thinking and tuning of APAP, CPAP therapy.

here is the latest in terms of centrals (PURPLE, still dominant)