Over-titration and CSAs?

[stienman]

I've seen occasional references to the idea that higher pressures appear to increase central sleep apnea events, and a few searches online suggest the term "over-titration" for using pressures greater than titration recommends.

Given that I'm dial winging, and haven't been professionally titrated (and have no desire to, given the cost and effectiveness of the APAP I'm using), I believe I need to know more about this.

The topics pinned at the top of the forum don't appear to cover this aspect of titration. Where should I look for references and data about this issue?

[LSAT]

Titration is a picture of your situation during 1 night....Once you start treatment using a data capable machine, you can monitor your nightly events using Sleepyhead and make whatever pressure adjustments are necessary to fine tune your therapy. CAs (Clear Airway events) can be ignored if they are spread out and your AHI is reasonable.

[palerider]

I've seen occasional references to the idea that higher pressures appear to increase central sleep apnea events, and a few searches online suggest the term "over-titration" for using pressures greater than titration recommends.

what you're asking about is "Complex Sleep Apnea" or CompSA.

some people, (I forget the percentage) start to develop central sleep apnea, usually at higher pressures, (typically over 10cm) even though they show no central apnea at lower pressures, or during a no pressure sleep study.

it really has nothing to do with 'over titration' whatever that is.

there are various theories about why this happens, one prevailing one has to do with co2 sensitivity, and the extra ventilation of cpap can cause them to blow off a bit more co2, which depresses their respiratory drive.

EPR can also have this effect in some people, since it increases the amount of respiration.

if you don't see increasing central apneas, then I'd suggest not worrying about it. modern machines don't increase pressure with centrals, so they tend not to exacerbate the problem for the small percentage of people that have CompSA.

[jnk...]

"Over-titration" can have a few slightly different meanings, depending on context. But it is usually used in the context of one steady CPAP pressure being prescribed.

Patient dial-winging with a full-data machine is usually all about getting the lowest AHI possible. If raising pressure were to increase your central events, that would show up in the data. That prevents "over-titration."

Furthermore, if you are running the machine you have listed in auto-titrating mode, the machine is programmed only to raise pressure in response to signs of obstruction. For most of us, that algorithm works great. In a few rare cases, autos can misread your breathing and needlessly increase pressure. But again, that would show up in the data if that caused central events for you.