CPAP setting derived from APAP results

puffing billy · Post by **puffing billy** » Fri Dec 22, 2006 1:48 pm

Having never had a titration study I have always wondered what pressure setting would be used for a straight CPAP machine.
Results from my APAP from my encore show the following usage
580hrs @ 9
320hrs @ 8
200hrs @ 10
80hrs @ 11
40hrs @ 12
10hrs @ 13

With AHI vs pressure
AHI 1.2 @ 9
AHI 1.3 @ 11
AHI 0.4 @ 14

My guess would be a pressure of 9

Can anyone enlighten me

Billy

oldgearhead · Post by **oldgearhead** » Fri Dec 22, 2006 1:54 pm

A sleep doc would probably prescribe 10 cm/H2O for CPAP and 8 -14 for APAP. .

puffing billy · Post by **puffing billy** » Fri Dec 22, 2006 2:00 pm

Thanks
Sounds like a logical answer.
I have my APAP set at 8.5 to 15.
Would there an advantage to dropping it to 14?

Billy

Sleepless_in_LM · Post by **Sleepless_in_LM** » Fri Dec 22, 2006 2:03 pm

oldgearhead wrote:A sleep doc would probably prescribe 10 cm/H2O for CPAP and 8 -14 for APAP.

I would agree. My sleep doc shoots for the 95th percentile. If my math is right that would put you between 10 and 11.

Wulfman · Post by **Wulfman** » Fri Dec 22, 2006 3:19 pm

IF you're going to go to straight CPAP (single pressure), if you get one that collects data (like the Pro 2) and have the software, it doesn't matter what the initial setting is because you can determine what works best for you over the long haul.

You won't know (overall) how a single pressure works for you until you've used it for awhile.......and over time, your setting may need to change.

Best wishes and Happy Holidays,

Den

oldgearhead · Post by **oldgearhead** » Fri Dec 22, 2006 3:36 pm

Would there an advantage to dropping it to 14?

I wouldn't think so, because you don't seem to need even 14 very much.

HP · Post by HP » Fri Dec 22, 2006 4:09 pm

How did your doc write the script with no titration?.......APAP, 4-20?

Anyway, I would get your myencore curve out that shows the plot for AHI vs. Pressure. Have you shown this to your doc?

I'd want to confirm that around 15 or above, the AHI heads back up.

Ideally, I'd want the cpap setting to be right where the curve "bottoms-out" at the minimum AHI. Your pressures tend to be several cm-H20 greater than mine. Since I'm not a doc who has seen all your data, I would not know if you might even be a candidate for Bi-PAP.

Your data suggests that there is not a deep drop in AHI over a several cm-H2O pressure range. Interesting data.

My $.02.

Goofproof · Post by **Goofproof** » Fri Dec 22, 2006 4:51 pm

Your machine is telling you your AHI is .4 @ 14 CM, that is the CPAP pressure you would need to clear the most events, hence the cpap setting.

The idea of APAP is to use lower treatment when needed, the idea of CPAP is to use whatever pressure needed for the best AHI.

Your machine can be set at CPAP and still collect the data. if you enjoy the leaks that come with using higher pressure, you can. With the software you can increase the pressure until centrals get higher, as long as the AHI goes down. Decisions need to be made on several days data or a weeks, one change at a time. Jim

puffing billy · Post by **puffing billy** » Sun Dec 24, 2006 7:04 am

I was just curious really.
Also if something happened and I got stuck some how I could use a CPAP if that was all that was available.

Billy

DreamStalker · Post by **DreamStalker** » Sun Dec 24, 2006 9:29 am

I was titrated at pressure of 10 cm but when I asked my sleep doc for an APAP he changed the Rx to 8 - 13 cm.

You should try and get yourself a copy of MyEncore or Encore Pro Analyzer (PM me if you need) and look at the plot(s) sugeested by HP for AHI vs. Pressure and perhaps also OAI vs. Pressure and HI vs. Pressure. Hopefully, all three have the same shape and it will be easy to determine by reading the pressure where they dip aat the bottom of the U-shaped curve.

If they do not all match you will have to determine which is best for you ... OAI or HI curve ... by selecting which ever one you think is providing you the best benefit of O2 saturation.

- r

Linda3032 · Post by **Linda3032** » Sun Dec 24, 2006 2:58 pm

Billy, on the other side of the coin:

If you don't want to get too technical with all the numbers and data, you know you spend most of your time at 9 or 10. If you feel good at 9 or 10, then that's where I would set my machine (if it were me). Why set the machine all the way up to 15 if you don't need it that high most of the night?

Remember, any AHI under 5 is considered normal with no need for cpap therapy. So, even if your AHI's were at 5, you would be fine.

To me, 9 is much more comfortable than 15, even if a few apneas are missed.

Why blow your brains out if you don't need to?

(and that's just my $ .01 )

Snoredog · Post by **Snoredog** » Sun Dec 24, 2006 4:00 pm

your score of 1.2 @9cm pressure is excellent.

If those were my numbers, I would weigh the good with the bad, for me that additional 5cm pressure to drop the AHI by 1 isn't worth tolerating the extra pressure as pressure can carry its own side effects, such as aerophagia, more mouth and mask leaks not to mention a more noisy mask/machine.

I'd stick with the 9cm pressure if it were me. So your AHI may jump to 2 it is still under 5 which is considered normal.

I would only increase if I felt better doing so.