(12-04-2014 06:01 PM)AshSF Wrote:
(12-04-2014 03:17 PM)Galactus Wrote:
My 90% pressure has ranged b/w 10.6 to 11.1 cm H2o. So the machine is covering a lot of ground from 4 to 10.6. My peak pressure goes up to 14.5.
(12-03-2014 11:27 PM)AshSF Wrote: You may want to use Optistart feature of the PRS1 60 series Auto. That will take care of start pressure.
My experience with pressure changes:
I started my 60 series Auto with a 4-20 range (as my physician suggested). I stayed on it for 45 days and my AHI settled to < 0.5 with an occasional 1.x within 15 days. So why bother with changing any pressure if the machine is doing its job AND I feel good thruout the day. I analyze my data with sleepyhead everyday and actually look at my waveform with a fine toothed comb. My steady state RDI is less than 3. Flow limit index is ~2.0.
I got an urge to experiment and raised my min to 5. Stayed on it for 11 days. The AHI was still ~0.5.
I raised the min again to 6. Have been on it for 14 days. My AHI is a shade above 0.5 but its statistically insignificant increase.
So my AHI is essentially same at 4-20, 5-20 and 6-20.
The stated objective of PRS1 is to give you as little pressure as possible to make it more comfortable. So IMHO, if the machine feels you are doing great on 4 cm H2o at a certain point in the sleep, so be it. There are advantages of lower pressures, as long as the AHI number is acceptable. I trust the PRS1 algorithm to decide whats best. And it is working so far. I don't know how it will be as time progresses. YMMV.
The key of why this works for you is the information you left out, and that is what the pressure is that maintains your ahi at .5 or below. For some a max pressure of 7 is all they need to maintain an ahi of .5 or below. If that is the case than having the machine set at 4-20 is meaningless as it never rises above say 7 and so it's really set at 4-7 anyway even though it can get to 20.
For someone like me titrated at 18 a setting of 4-20 would mean the machine would waste the first hour of my therapy getting to where it needed to be and likely suffocating me most of the way as I find it almost impossible to breathe with the mask on at below 8.
the OP indicated their pressure which is why I suggested the settings I suggested so as to eliminate the low end wait and difficulty breathing that most experience on the low end of the 4 pressure settings.
My personal unit setting at 13-20 allow me to get right to sleep experiencing no discomfort and allow the machine to adjust as needed all the way through to 20. I also have a bipap which I am using and am setting the lower end down slowly as it rarely seems to rise on epap and stays steady at 13 indicating I might be ok with 12 11 or even lower, but I am experimenting slowly. However my ipap is still always at 16-20 so setting it below would defeat the purpose. YMMV depending on your pressure settings as will the OP's.
Although, as you correctly pointed out, if my 90% pressure was 15 or higher, this strategy of leaving it wide open at 4-20 may not work to avoid clusters of events.
But how will a newbie like myself know whether 4-20 will get him to 0.5 AHI or is it 5-20 or 10-20? All one can do is start from 4-20, give it 7-14 days to settle and them bump up the pressure 1 at a time, until the desired result is achieved.
If I followed the prevailing conventional wisdom of setting the range of +2 and -2 from the 90% pressure, I would be sitting at a range like 8-12. This will give me higher pressures than I need most of the time, And on the other end, it may not tackle the events that PRS1 60 does by going up to 14.x cm H2o occasionally.
Keep in mind that 4-11 isn't really that wide of a setting overall, especially compared to 4-20. If you were using ramp on a 15-30 cycle you would be at your base when the machine kicked in. I'm set 11-18 max 20, which is pretty equivalent.
Good you did get my point on being 15 or over, that was what I was trying to say.
As a newbie I agree with you 100%, if you don't have a titrated script with a number then using opti start and wide open for a week would get you to a starting point. However the OP here listed a pressure set which is why I said don't waste time with the low setting and get setup narrower.
I'm not certain the prevailing wisdom is +/-2, imho it is +/-4 along with flex and or pressure support. If I were you and 90% was 10 I would have set 8 (because under 8 for me I can't breathe) if you are comfy you could go 6 and top of 14. That would cover you all around, and allow no discomfort at the low end.
For me I was 18 and given a brick at 18 flat. When I got my bipap I initially set it at 13-20 I felt much much better at those settings and I am still tickling it now to get it exactly where I want it. But I can tell you it covers me all around and the narrower setting allows the PRS1 a faster reaction time during the hunt and peck and it helps me breathe better without that low initial pressure feeling.