Apnea (OA) vs Hypopnea

[jnorris]

Is there any advantage in one of the following AHI scenarios?

At 7cm H2O
AHI =6 – OA = 1, H = 5

At 9cm H2O
AHI = 6 – OA = 5, H =1

The AHI numbers are the same but the components are different.
I would rather have a partial reduction of breathing than no breathing at all so I favor the first scenario.


Thanks

John

[DreamStalker]

you answered your own question.

[mindy]

IMHO, you can't really go by single nights .... run at each pressure for a week or two and see what happens.

Mindy

[jimbassett]

In the beginning of my therapy I was misleading myself by using one or two nights readings then adjusting my pressures from there. After nearly six months of chasing my pressures all over the place I decided to start over with my titrated pressure and go for two weeks at a time using the same mask each night. Then I averaged the two weeks readings. Then I would change to another set of pressures and go for another two weeks ect.

After four months I came up with a set of pressures that had some meaning and I have been using them. I started noticing the better feeling mornings after several nights. This I feel is the only way to be sure you are getting the proper therapy. Good Luck in your endeavors. jim

[jnorris]

Mindy - I totally agree with you.
The numbers I provided above are hypothetical for the example.

My real numbers are based on about 1 month of data with the machine operating as a CPAP with a setting of 8 and 9 with cflex and as an APAP with a range of 7-10 (aflex) and 8-12 (cflex).

So far I feel the best on the 7-10 APAP with aflex. My AHI numbers are about the same at 7cm vs 9cm. The OA is the biggest contributor at 9cm and H is the biggest contributor at 7cm.
Operating as a CPAP with cflex my AHI numbers at 8cm and 9cm are a little lower but I felt very foggy when I got up and got tired earlier in the day.


John

[mindy]

John,

It sounds to me like your numbers are close enough that if it were me, I'd go with how I feel. Remeber too that there is always some measurement error with any machine (people, too) and how it distinguishes between apneas and hypopneas is also prone to some amount of error.

Mindy

[Snoredog]

You should use the pressure that results in the BEST sleep as measured by how you feel the next day.

when looking at data in your example, the pressure resulting in the lowest OA should be the one you use as OA should be a complete collapse of the airway and lack of air flow resulting in the greatest drop to SAO2 levels. HI is a calculated or lower severity apnea event, the machine is capable of detecting complete cessation of air flow but not smart enough to differentiate between obstructive and central.

Your OA most likely went up at the higher pressure most likely because some of those OA were not actually OA's but central apnea or CA's possibly seen on any PSG you might have had. But many people SDB events follow a bell curve before getting addressed, if you are on the up side of that bell curve you may need to go much higher before things drop down again.

While the 6cm pressure produced the better result it may be difficult to breathe at that low a pressure.

you should try another setting by setting the Max=8.0 thereby limiting the machine from going higher then compare your OA score to the others.

Note: features like A-Flex don't work at lower pressures (requires 6.5cm pressure).

[mindy]

Snoredog,

That's helpful ... I didn't realize that OAs could be CAs. What then are "non-responsive" events?

thanks!
Mindy

[jnorris]

Below are my numbers.

[DreamStalker]

I think SD is right ... your chart does show that apneas begin to run away with higher pressure (a sign of centrals).

You may be one of those who does better on CPAP at 8 or 9 cm ... or you could talk to your doc about getting a bilevel machine. However, your doc should have known you were sensitive to central apneas and should have put you on a bilevel to begin with.

Until you get it resolved, you are probably best on CPAP mode at 8 or 9 cm.

[Snoredog]

notice the NRI's beginning at 10 cm (how did I see that, the chart wasn't posted during last reply)? You may be able to blow thru those (going over the bell curve to the other side) but I doubt you will feel any better but you won't know until you try.

those CA's are a sign of unstable breathing that is all they mean, if your breathing is stabilized (how ever that is accomplished) those will go away. If you are still seeing your sleep doc you might want to ask him/her about those and possibly UARS.

[Guest]

Great information here! I am learning a lot.

My PSG shows the following. No centrals were indicated.
I feel much better on APAP with aflex 7-10 than any other setup. 8cm was the highest pressure used.

Pressure---AI----HI
5-------------0-----8.9
6-------------0------0
7-------------0------1.6
8-------------0-------1.1

John