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+--- Thread: narrow vs wide range apap (/Thread-narrow-vs-wide-range-apap)
narrow vs wide range apap - ewags - 02-25-2020
Hello! I'm about 2 weeks into using APAP and when I started the prescribed pressure was 5-20 and after good advice and posting OSCAR charts I've narrowed my pressure from 10-15. Here's my question. My normal max pressure is about 12. If I could tolerate comfortable that pressure from the beginning of the night what would be the advantage to just set the minimum at around 12 so I don't experience the events that trigger the machine pressure increases. Then the machine is set up to adjust upward to more extreme events (REM sleep on my back is bad etc). Also making the assuming that centrals don't increase with the increase of pressure. What is the advantage of the slower ramp up (say min pressure 8) when there are apnea related events between 8 and 12, other than comfort and possible CPAP induced CA events?
RE: narrow vs wide range apap - 70sSanO - 02-25-2020
I've always been in the narrow range camp. My ASV has kind of thrown that out, but on APAP I keep my range to generally 2/3 under and over. I would consider your 10-15 to be a narrow range.
One OSCAR graph I like to look at, although it is generally dismissed, is the Time at Pressure. For me it is an quick and easy way to see the pressures where the events take place. I just scroll the graph line and pressure, time and events show in a pop up window. For me, may not apply to others, it seems that I get most of my events at the high end of the pressure, But I'm only at that pressure for a minute or two.
If you can tolerate 10-15, without disruptions in sleep, I don't see a reason to narrow it any further.
John
RE: narrow vs wide range apap - ewags - 02-25-2020
Thanks for the info...do you take action based on that information when you see the events occurring at the highest pressure?
RE: narrow vs wide range apap - 70sSanO - 02-25-2020
Yes. I generally want to be within a couple over my events at the highest pressure.
As I said my ASV has thrown out a narrow range. It is a different animal, but I set my EPAP to 6-8 and pressure support to 2-12. This gets me to a max of 20. My events have fallen in the 17/18+ range but never at 19. At 20 I feel I have a buffer. If events happen close to 20, I’d probably raise it. Even when I was on APAP, I ran a slight buffer.
Hopefully others will chime in with their views.
John
RE: narrow vs wide range apap - sheepless - 02-25-2020
with apap and vauto I have to limit my max ipap to about 13.4 cmw to avoid leaks and aerophagia, even with a collar. with asv, I had pressure cycling up to almost 25 cmw on occasion but because the asv is so quick to raise and lower ipap I was never conscious of it and I don't think it contributed too much to leaks. (with limited max ipap, most of my leaks occur in deeper sleep and relatively lower pressure). in my case the asv responded rapidly to my periodic limb movement induced flow limitations, up and down every 10 or 20 seconds for as long as the plm episode. while I was not aware of the pressure swings, I find I feel better with a capped max ipap with vauto even though my ahi is quite a bit higher. I guess I lean toward the camp that uses a wide range to titrate down to the lowest effective min and max pressures.