AHI vs Oxygen Saturation Levels

ballast949 · Post by **ballast949** » Sat Apr 16, 2005 2:58 am

I have a theory question: Is there a direct (more or less) relationship between my AHI reading and my Oxygen level? I am interested in using an APAP machine, since how can you tell what you are doing right or wrong if you don't have measurable results?. Since my sleep study placed a lot of emphasis on oxygen saturation levels, I wonder if, to be complete, I should invest in a recording oxygen level monitor ($$$). But, if a low AHI implies a high level of oxygen saturation, then monitoring AHI should be close enough.

Mikesus · Post by **Mikesus** » Sat Apr 16, 2005 4:45 am

Your question is a tough one. In some folks AHI is directly linked to o2 desat. In others it isn't. The best way to find out is during a titration study. If your desats stop while on therapy, then it is directly related. If it doesn't you might be told that you need supplemental O2.

Did you have or are you scheduled for a titration study?

ballast949 · Post by **ballast949** » Sat Apr 16, 2005 1:26 pm

Hi Mikesus,

yes - when titrated to 23 cm I went from an O2 desat of 80% and an AHI of 74 to an O2 of 92% and an RDI of 6.7 - assuming RDI & AHI are the same thing....

Guest · Post by **Guest** » Sun Apr 17, 2005 12:40 pm

Respiratory Disturbance Index (RDI) is all of your sleep events. It’s the number of apneas (obstructive, central or mixed) plus hypopneas per hour of total sleep time as determined by all-night polysomnography . It is also the same definition for AHI Apnea Hyponea Index.

If your a just an OSA suffer then yes your desats would correspond with your sleep events. Now if you have COPD or some other lung disease then no it may not. I would not waste your money on an oximeter you don't need it. It’s just going to drive you Crazy. For the most part if you do not know what you’re doing you will get a poor reading during the night and may think it’s real . This will make you crazy LOL.