Confused about AHI with ResMed S8 II

[Pakratt]

I'm new to CPAP and went into Results on the machine this morning and found AHI=24.5, AI=4.7, HI=19.8 with 7.49 Hrs of Usage. I got these results by going into the machines "Clinical Menu" and reading the "Efficacy Data". Does anyone know if the unit is calculating AHI using the hours I was on the machine or is it just the number of events per hour or per session, etc.?? My overnight sleep study showed an AHI of 20 prior to being placed on CPAP and when titrated to 9 it went to zero events for the next 4 hours. If I am still having an actual AHI of 24 then something is not right. Suggestions?????
- Thanks -

PS... Leak rating was 0.4 and mask is properly identified in machine.

[wlo2008]

The AHI is the combined of Hypopneas and apenas an hour. What type of mask are you using? You could be having a large leak causing the apneas. Go into the clinical data and check what your leak rate was for the night. Then check the manual for your mask and see what the avearge leak rate is for the pressure setting.

[Slinky]

Its best to stay out of the Clinicans Menu. You can access your Efficacy Dat w/o going into it IF the SmartData option in the Clinicians Menu is turned ON.

To do so, press the Left and Right buttons and hold for 3-4 seconds. If Efficacy Data doesn't come up on the LCD screen then go into the Clinician's Menu and turn the SmartData option ON. Thereafter you can just do the Left/Right button press to access your Efficacy Data w/o the risk of accidentally changing any of your therapy settings.

Check your Leak Rate in the Efficacy Data. THAT is most likely the reason for your high AHI. AHI = the number of apneas AND hypopneas PER HOUR. Your S8 II is probably chasing leaks causing that high AHI.

Whilst you are in the Clinicans Menu also check your Mask Selection to make sure you have selected the correct mask. If you are using other than a Resmed mask you should be using the Standard mask selection and the Reported Leak rate will be MINUS .4 L/s or 24 L/M from your TRUE leak rate which you will then have to calculate yourself.

And, why not go into the User Control Panel at the top of this page, click on Profile, and enter just exactly WHICH Resmed S8 II you are using, plus which mask you are using. Then we won't have to keep asking you and you won't have to keep telling us what equipment you are using. Use text, the avatars take too long for those of us w/slow speed dial-up to check.

[ozij]

Thanks for filling the profile.
With you mask, presumably at a pressure of 9, a leak rate of 0.4, on Resmed machine is waaaayyyyy to high.

When using a Swift LT you should tell your machine to calculate for a Swift. And your leak rate should be reported as 0 - since Resmeds subtract the vent flow rate from the reported leak.

You machine reports 0.4, add to that the expected 0.3 for a Swift at 9 cm. and you're leaking a a furious 0.7.

You've go to find the source of the leak, and stop it.

O.