95%/ max pressures rising - wondering why?
I have been on APAP now 4 months - about a month ago I increased my minimum pressures with a lot of improvement in how I feel.
I was expecting 95% and max pressures to stay roughly the same (though obviously average pressure would rise), but this was not the case. Rather than most of the night flatlining along at the new higher minimum, much of the night was still north of that. In fact I have eventually pushed my minimum to higher than my old 95%
The numbers..
Initial range 7-12, 95% - 9.5, max never above 11
Now range 10-13, 95% - 11.0, max touches 13 once or twice a night.
I am feeling improved, but I was wondering whether the rise means.....
a) auto-titration by my machine was undergoing things, or
b) I am sleeping better and more deeply, hence necessary pressures are rising
c) other?
RE: 95%/ max pressures rising - wondering why?
Raising the minimum pressure lets the machine acheive therapeutic levels faster, and that may be at higher average and 95% pressures. Your experience is not unlike a lot of other new users that have started at 4-20, then gradually increased minimum pressures until they stay within a range of just 3-5 cm. The higher minimum pressure seems to prevent events resulting in better sleep, and fewer pressure changes through the night is less disruptive. Looks like a very normal progression to me. Well done!
RE: 95%/ max pressures rising - wondering why?
Thanks for the reply Sleeprider.
I was wondering though why the max pressures had risen after appearing pretty stable at 95-100% values of 9.5-11 when I had already narrowed it from the 4-20 to a 7-12 range on the initial auto titration. I pushed pressures to 10-13 to try to deal with ongoing fatigue.
I should add my formal titration was happy with 5 cm pressure on my side, 6 cm for on my back in REM.
If my current pressures are 95-100% values of 11-13 now, why did the machine only take me to 95-100% values of 9.5-11 before? Makes me wonder if perhaps the machine algorithm can underdo things, let alone the formal titration study that suggested 1/2 my current pressure would be fine?
RE: 95%/ max pressures rising - wondering why?
In my experience with this machine, tend to treat flow limitation aggressively and pressure can hit the maximum even with the majority of events has been dealt with at a lower pressure
Unlike apneas, flow limitations are not part of AHI but can be troublesome, so decided on a compromise between FL and pressure rises and limiting maximum pressure to 13 with no EPR ... YMMV
95% percentile pressure means pressure was at or below that number for 95% of the time
RE: 95%/ max pressures rising - wondering why?
I had the exact same experience and Sleepriders answer is awesome
What it mean is you've done a better titration than the sleep lab did.
(05-05-2016, 09:50 PM)Sleeprider Wrote: Raising the minimum pressure lets the machine acheive therapeutic levels faster, and that may be at higher average and 95% pressures. Your experience is not unlike a lot of other new users that have started at 4-20, then gradually increased minimum pressures until they stay within a range of just 3-5 cm. The higher minimum pressure seems to prevent events resulting in better sleep, and fewer pressure changes through the night is less disruptive. Looks like a very normal progression to me. Well done!
I started @ 5-15 and ever time I stepped up the low end the 95% moved up with it until I reach a low of 12. At 12 my AHI starting going back up. I had the same experience raising the upper limt when I hit 16. I backed them down .2 from where the upward swing appeared. Therefore, I consider @ 11.8-15.8 my sweat spot and I am no longer changing my settings.
2004-Bon Jovi
it'll take more than a doctor to prescribe a remedy
Observations and recommendations communicated here are the perceptions of the writer and should not be misconstrued as medical advice.
RE: 95%/ max pressures rising - wondering why?
Your profile indicates you are using Sleepyhead. In addition to what has been said previously, have you looked at leakage? Your original pressure was nice and low. One thing i have discovered that when i have leaks, my pressure zooms up, which compounds the problem. Do you see any correlation between leak and increased pressure? One of the masks i am trying and like, seems to fail miserably if pressure goes above ten.
Often these rises in pressure are not related to an event. My AHI is almost always under 1.0. I guess i would not worry about the pressure too much if it seems to be linked to leaks, but if it is accompanied by events, then maybe the machine is trying to compensate for the event....which is good.
RE: 95%/ max pressures rising - wondering why?
My leak rates have been stable at 2.4/12 med/95% drgrimes, and specifically I don't see any correlation of leaks with pressure rises.
Thanks guys for the reassurance.
RE: 95%/ max pressures rising - wondering why?
(05-08-2016, 11:36 AM)Carbon Wrote: My leak rates have been stable at 2.4/12 med/95% drgrimes, and specifically I don't see any correlation of leaks with pressure rises.
Thanks guys for the reassurance.
These are low numbers, nothing to be concern about, ResMed define acceptable leak less 24 L/m, above 30 L/m distort the data
The software charts might give you some hints of the pressure rises
