21 ahi

New guy here.

I am 49 and diagnosed with osa. I had an ahi of 31 during my test. They say I have moderate to severe.

I was given apap dream station and only had one sleep lab.

At first I could not use it, I woke up gasping for air or took it off. I thought it was because of my nasal congestion and also I could not exhale against the pressure. However, lately I felt so tired I tried it again.


This time I read up and changed the settings. It was at 5-20 and 1 a flex and I changed it to 3 a-flex. I was able to sleep the whole night through I think because i could easily exhale now with flex at 3.

But it said I had 22 ahi. Does this mean I had 21 real ahi or 21 ahi that it corrected without me actually suffering an apnea?

I turned it up to 9 the next day and it felt like hurricane andrew was on my face. Tonight I will go back down to 7 or 6.5 and see how many ahi I get.

Sorry for being scattered but the main question is ahi- are those real events or ones that the machine treated?

They are NOT apneas that would have happened had the machine not been there to treat them.

Detecting that is simply not possible.

But they might not be real either. Sometimes the machines report what we refer to as Sleep-Wake-Junk (SWJ), basically false positives because we are breathing erratically, and maybe even awake.

Your device is capable of writing data to an SD Card, and there is software that can be used to print graphs that you can post. This way members can look at your graph, give opinions on your therapy and suggest improvements.

Read the pinned topics to get started.

Dog Slobber wrote: ↑

Sat Oct 17, 2020 2:59 pm

They are NOT apneas that would have happened had the machine not been there to treat them.

I don’t understand exactly what that means.

The AHI shown on the machine's LCD screen or software reports are apneas that happened despite therapy.
You don't want a high AHI using cpap.
Now sometimes the machine mistakes awake breathing irregularities as some sort of apnea event and they don't really count if we aren't asleep but we don't ignore an AHI of 21 on cpap until we either can explain them away as awake breathing or we evaluate the pressure.

If you slept soundly for the most part.....you had 21 apneas per hour even on the cpap machine. Obviously something is wrong and current settings are far from optimal.

These machines don't report apneas they prevented....they report apneas they think happened and that's not good at all.

You need to be using the available free software (OSCAR) and see exactly what kind of events you are having and when you are having them and then we can proceed with your options.
You might need more pressure...your might need to turn Flex off...any number of "mights" but we have to start with the software detailed report evaluation.

Ander35 wrote: ↑

Sat Oct 17, 2020 1:26 pm

This time I read up and changed the settings. It was at 5-20 and 1 a flex and I changed it to 3 a-flex. I was able to sleep the whole night through I think because i could easily exhale now with flex at 3.

Funny those were the same settings they set my machine at the first time. It took some time for me to tweak the pressures correctly. If you are having that many real events then clearly the machine was not able to clear them. But we won't know for sure if they are real until you post some charts and Pugsy can look at them. I have noticed that when I set my flex to 3 my AHI is higher. If I put it back to 1 then it is much lower.

Settings of 5 to 20 aren't really "settings" they are pretty much the machine's default from the factory settings plus one. They come with the default settings of 4 minimum and max of 20. It's done often when someone didn't have an in lab titration sleep study. Not having an in lab titration study...unless there is some sort of unusual problem it's not that big of a deal. They aren't all they are cracked up to be and they don't always get it right either. I had one and came out of it with less than optimal prescribed settings. I didn't sleep well during the titration study....only got 6 minutes of REM out of the entire night and REM is where I happen to need a lot more pressure because my OSA is worse in REM.

Most people will have a problem with the 4 cm minimum starting point. Just not enough air moving for comfort. We won't suffocate at 4 cm but it can sure feel like it for some people.

Flex...actually doesn't kick in completely until the pressure is at 6 cm or higher. Sometimes using Flex can either allow more obstructive events to happen because during exhale the pressure drops down below the line where the airway is held open or sometimes using it causes more central apneas. Which is why we always like to see the event category. To fix a problem we first have to identify the problem. The fix for obstructive apneas won't fix central apneas and could potentially make things worse.
That's where the software comes in because the AHI on the LCD screen of a Respironics machines doesn't tell us what kind of apneas a person is having and it's actually a critical data point in terms of therapy.

Flex settings...are NOT a 1 cm drop during exhale like ResMed machines. Instead the amount of drop during exhale is based on how forcefully one breathes. If a person is a shallow breath kind of breather they aren't going to get as much of a drop as a person who is a forceful breather even if the Flex setting is the same.
The most a person can have as a drop with Flex at the max of 3 is a 2 cm drop and you get that only if you are a forceful breather.