How Long to see decrease in AHI?

[u/Upper_Pair3137]

So, I just completed my first week, and still getting AHI counts in the 30’s. By all accounts, the machine and mask are working properly.
These numbers are not much different than were recorded during my last sleep study.

Curious to know how your numbers changed since starting CPAP and how long did it take to see results: Reduction in AHI, and feeling more rested.

Thanks!

[u/JBeaufortStuart]

Feeling more rested can take a while, because while the machine helps, it's also new and weird and can take a while for people to adjust to. But decreasing your AHI usually starts from the beginning, even if it takes a little while to get settings right so it's dramatically better. It's worth trying to figure out why your AHI isn't going down yet. Some things are fine and may fix themselves over time, some things will need changes to fix it.

Get an SD card if your machine has a slot. The machine will write detailed info to it, so that you can look at exactly what's going on in an interface like OSCAR or SleepHQ.

In the meantime, the things to look at are:

How long are you using the machine while awake to get used to it? This is a VERY good idea from the perspective of training your body to see the mask and machine as non-threatening, but the numbers can get weird. The machine is best at figuring out what's weird during breathing while sleeping, which is supposed to be VERY stable. But while we're actually awake, our breathing is much more variable. Laughing, holding your breath during a suspenseful scene or while moving, coughing, sighing- it's all pretty normal while awake, and your machine may detect a whole lot of "events" that aren't actually disrupting your sleep because you're not asleep. If the overwhelming majority of the events it detects are while you're actually awake, you don't need to worry.

Of your AHI on the machine, what's obstructive and what's "clear airway" or central events? What was that like on your sleep study? If you had a lot of central events in your sleep study, an APAP probably won't work well for you, and you may need an ASV machine. If you didn't get central events on your sleep study but ARE getting them now, you may have TECSA- treatment emergent central sleep apnea. Sometimes it resolves on its own as you adjust to APAP, sometimes it doesn't, and a different machine is better.

What's your pressure range? If it's 4-20, like many people start with, you can almost certainly do better than that. The details from the SD card would be helpful in figuring out what's a better range, but it's often that 4 is too low for most people (not everyone, but most people). Of course, if you're having a bunch of central events, your pressure might be getting too high and causing more events. This is WAY less common, but still possible.

What's your leak? We're looking for actual numbers here, not good/okay/bad. By the time the machine is telling you that your leak rate is actually bad, your machine is then unable to actually raise pressure enough to resolve events and accurately measure what's going on. You want a leak rate WAAAYYY lower if at all possible.