"Hypopnea" measurements are bogus, right?

[Bobmcdonld]

If I understand what hypopnea means, it requires a measurement of blood O2 level, which the CPAP does not measure. Therefore, whenever the printed out data refers to hypopnea index or AHI, it's nonsense, right? Am I missing something?

Bob

_________________

CPAPopedia Keywords Contained In This Post (Click For Definition): CPAP, AHI, Hypopnea

[CompuTech007]

Correct but at least it does show when abnormal shallow breathing is occuring. I know that in my sleep study I had many hyponea events. For me if I see a lot it's a good warning sign that my machine might not be set correctly (like when I first started using it). But since I've adjusted and increased my CPAP machines minimium pressure I've only seen a few and mostly at my lower pressures.


Medical Definition says:

In the diagnosis and treatment of sleep disorders, a hypopnea event is not considered to be clinically significant unless there is a 50% (or greater) reduction in flow and an associated 3% (or greater) desaturation in the person's O2 levels for 10 seconds or longer, or if it results in arousal or fragmentation of sleep.

_________________

CPAPopedia Keywords Contained In This Post (Click For Definition): Arousal, CPAP, Hypopnea

[ozij]

Yes, you are missing something
.
Hypopneas have various definitions. Data tracking machines define some changes in the air flow as hypopneas. These change hint at partial obstructions. Data tracking machines don't base their reporting on O2 saturation, only on the flow.

You are free to disregard those partial obstructions - but I wouldn't. They are informative about how your treatment is effecting your breathing.

When I raised the bottom pressure on my APAP (and narrowed the range), the number of events defined as hypopneas reported by my machine dropped, and I slept better. Call those events what you will - having less of them was better for me.

O.

[Wulfman]

You might want to read this thread:

viewtopic.php?t=26220

The data collected in the machines is based on air flow and therefore not as exacting as in the sleep lab. However, the manufacturers obviously put a lot of thought into this, so I take it seriously.

Den

[Bobmcdonld]

Thanks for your dispassionate, factual reply.

Bob

[dutchbrown]

In the diagnosis and treatment of sleep disorders, a hypopnea event is not considered to be clinically significant unless there is a 50% (or greater) reduction in flow and an associated 3% (or greater) desaturation in the person's O2 levels for 10 seconds or longer, or if it results in arousal or fragmentation of sleep.

That is interesting, especially the highlighted portion... I had a sleep study and had many hypopnea events in which my breathing was reduced but my O2 never dropped more than 2%. However, my main problem was the number of arousals due to those events. Hence they did not put me on CPAP during the study, but instead, they put me on APAP only after the DR review the sleep study chart.