CPAP v APAP question.

[Andysee]

Hello all.
I know I should have asked this at the sleep clinic however here goes.
We know the difference between a CPAP and APAP machine and there has been much discussion here about their different attributes and benefits of each. It seems most like the APAP’s and so do the sleep clinic staff. I was initially issued with a CPAP which was set to a constant pressure of 14 after the readings from my sleep study machine were interpreted by the sleep clinic. I quickly bought my own APAP which gives me the results of the previous nights AHI’s HI’s etc.
I am currently down to nightly averages of, pressure 9 to 10, AHI 6, AI less that 1 and HI’s 5 to 6. I interpret this as the APAP sensing my apnoea occurring then adjusting the pressure to compensate but in the mean time I still get the apnoea briefly because of the delay in the pressure change.
If I was still using the CPAP which I was issued would the constant 14 pressure prevent any apnoea occurring and, if the machine was capable of recording, would it show 0 for all readings of AHI’s, AI’s etc?

Best regards
Andy

[Joe McManus]

Different APAPs, or Auto-CPAPs, use different algorithms to adjust the pressure. You describe them as reactive where they adjust the pressure upon recording an apnoea event. That's part how they work but while doing so they will also adapt to being proactive.

The obstructions themselves can also be of varying severity so even on a fixed pressure of 14 a certain apnoea event may be so severe that it still would have occurred at 14.

If the titration suggested 14 for you but your Auto runs at 9.5 average, you could perhaps try and set your APAP at a fixed 14 for a while and see how you go.

But then again, an AI of sub one isn't bad at all. Supposedly healthy people will record the odd HI too so those figures don't look particularly worrisome to me. What's more important is the effect on your oxygen levels though. Another member here owns his own oxymeter and tests his blood oxygen levels occasionally. With an approach like that you can see for yourself whether a fixed 14 performs better than a variable 9 upwards.

[Andysee]

Thanks Joe.
I am very happy with my progress (diagnosed 76) in such a short time and am very happy with my machine but I just wondered if 0 on all counts was possible at 14. The way the machine performs is magic as I've only been woken a couple of times with high pressure so I think I will let the machine decide for me.
I don't know if it makes any difference but I have also been careful with what I eat. I've cut down on dairy and fatty foods and alcohol intake. I really miss my wine with meals. I intend to increase the wine intake soon and see if my nightly figures increase.

PS I think I posted this thread in the wrong place, should have been under CPAP machines?

Best regards
Andy

[Joe McManus]

Good choices. Less dairy will help avoid nasal congestion, avoiding fatty foods will be good overall and alcohol relaxes the muscles which can increase apnoea events.

A glass a wine is probably fine because it also thins the blood somewhat. Would probably best to drink it well before bed time so it can wear off.

I guess it could have gone in CPAP Machine though discussing the principles of APAP vs CPAP fits here too. I'll move it anyway, now you mention it.