AHI and Total Events Confusion

jrfoster · Post by **jrfoster** » Fri Oct 06, 2006 10:42 am

I talked with the sleep study center this morning about my sleep study because I have never seen the results (taken in May) of my study. My doctor simply said I have apnea and need CPAP.
The center told me that my AHI was 47.1. I had a total of 54 event of apnea and 68 events of hypopnea for a total of 122 events for the night.
If I had 122 events for the entire night, how can I have an AHI of 47.1?

Can anyone help me understand this? My doctor's office is not returning my phone calls thanks to voice mail messages.

Jeff

Bob... · Post by **Bob...** » Fri Oct 06, 2006 10:48 am

jrfoster wrote: Can anyone help me understand this?

AHI is the events per hour, so you evidently slept a total of 2.6 hours and had 122 events (122/47.1 = about 2.6).

Bob

svh · Post by **svh** » Fri Oct 06, 2006 10:48 am

I'm pretty sure the AHI is the total number of events (apneas plus hypopneas), divided by the number of hours asleep (not just in bed, but sleeping).

Snoredog · Post by **Snoredog** » Fri Oct 06, 2006 11:10 am

the Sleep Lab should have mailed you a copy of the sleep study, if they have not done that, call them up and request it. It is what you/insurance paid towards $3000 for.

but AHI is the SUM of obstructive events/60 (hypopnea + apnea/hrs), other events may contribute to RDI (Respiratory Disturbance Index), the sleep study report should tell you about all arousals which may interrupt your sleep.

but calculating the AHI is like svh indicated, you take the total time "sleeping" and divide that by 60 (hr). Then you take the events seen during that period and divide by the number of hours to come up with your AHI score.

It is also important to view the AHI individually to see:

Hypopnea events (HI)
Apnea events (AI, OA)

if a high number of AI remain with thereapy it may mean a pressure increase is needed, if a high number of HI remain it can mean the same and/or something else, copy of the sleep study helps you understand that.

jrfoster · Post by **jrfoster** » Fri Oct 06, 2006 11:34 am

Thanks to all for the quick reply!

I knew that I did not sleep hardly at all during the study, being a strange place, different bed, and hooked up to all those wires! The tech told me that I did sleep, but not for how long. Apparently not long at all.

I will get a copy of that study sent to me. According to some an AHI of 47.1 is borderline moderate to severe apnea. No wonder I get up tired after all that work during the night!~

Jeff

svh · Post by **svh** » Fri Oct 06, 2006 12:12 pm

My understanding is that, officially, anything over 30 is "severe". My AHI was 41.5 (mostly hypopneas), but my sleep doc rated me moderate because my oxygen never went below 92%. She said she takes into account AHI, Oxygen, and daytime sleepiness when deciding how to classify a patient's apnea.

jrfoster · Post by **jrfoster** » Fri Oct 06, 2006 2:05 pm

svh wrote:My AHI was 41.5 (mostly hypopneas), but my sleep doc rated me moderate because my oxygen never went below 92%. She said she takes into account AHI, Oxygen, and daytime sleepiness when deciding how to classify a patient's apnea.

Apparently my oxygen never went below 90%.

Also, I am just getting over (hopefully) a bout of imsomnia and need to be compliant with my therapy. The mask was instrumental in keeping me from falling asleep. I am going to try once again putting the mask on as I get into bed and see if I can fall asleep with it on. Otherwise I throw it aside, wake up numerous times during the night and wake up with a headache and feeling lousy all day.

Life is great if I can just feel good to enjoy it!

Jeff

Snoredog · Post by **Snoredog** » Fri Oct 06, 2006 9:42 pm

jrfoster wrote:
svh wrote:My AHI was 41.5 (mostly hypopneas), but my sleep doc rated me moderate because my oxygen never went below 92%. She said she takes into account AHI, Oxygen, and daytime sleepiness when deciding how to classify a patient's apnea.
Apparently my oxygen never went below 90%.

Also, I am just getting over (hopefully) a bout of imsomnia and need to be compliant with my therapy. The mask was instrumental in keeping me from falling asleep. I am going to try once again putting the mask on as I get into bed and see if I can fall asleep with it on. Otherwise I throw it aside, wake up numerous times during the night and wake up with a headache and feeling lousy all day.

Life is great if I can just feel good to enjoy it!

Jeff

jrfoster · Post by **jrfoster** » Sat Oct 07, 2006 8:28 am

Thanks Snoredog! When they send me the studies I will get a read on i

My major concern now is learning how to fall asleep with the mask on while I am fighting the isnomnia battle. I took myself off all prescription sleeping medications because they were making it worse for me during the day. I don't need to wrestle all night and feel like crap all day!

I'll just keep trying!

Jeff

AHI and Total Events Confusion

AHI and Total Events Confusion

Re: AHI and Total Events Confusion