[Diagnosis] Many clear airway events

[Wilberforce]

Hi,

I started CPAP treatment about a week ago, and am surprised by the number of Clear Airway events showing in OSCAR.  Is this anything to be concerned about?  My OSCAR report from last night is attached.

   

My diagnosis from an at-home sleep study was:

INTERPRETATION: The overall apnea/hypopnea index (AHI) was 64.3 per hour. A total of 331 apneas, and 133 hypopneas were recorded. AHI while supine was 64.6 per hour. The longest duration of the respiratory event was 58.0 seconds, and the average duration was 22.7 seconds. The baseline oxygen saturation was 92%; the minimum during the study was 81%. Microphone monitoring revealed frequent moderately loud snoring. DIAGNOSIS: Severe obstructive sleep apnea syndrome with moderate oxygen desaturations, worst while supine.

I did not do a titration study, and my doctor gave me a ResMed 11 set to APAP between 4 and 20.  I temporarily altered that to 5-15 while using a full face mask, then 5-12 for a nasal mask - in both cases because I haven't adjusted to the high pressure as yet and want to maintain compliance.

[Deborah K.]

Since no clear airway events appeared on your sleep study results, yours must be treatment-emergent. These will go away on their own or at least be significantly reduced.  Don't worry about them at all.

I suggest that you:

1. Set up EPR full-time at 3.  This will make your therapy a lot more comfortable and will decrease your flow limits, which are near-apneas, and lessen the efficacy of your therapy.

2. Turn ramp off.  You don't get good therapy while it is on.  

3. Set your pressures at 7-15.  You are bumping up against the 12 you have set, so again, your therapy is not the best.

Also    

[BoxcarPete]

The machine is trying to keep you at the max all night, so you need some combination of EPR and higher pressure. Many people find that EPR is more comfortable and eliminates their flow limits, but the caveat is that it can make treatment-emergent central events go up. I do recommend trying it since you do have significant flow limits and it often helps with that, but you may need to back off on it if you find it makes CA events go up. If that happens, it'll be your call whether to back off on EPR until you adjust to CPAP, or keep going with it if reducing your flow limits makes you feel more rested. Good luck!

[Gideon]

Let's see what these centrals look like.
Post a couple of 3- minute views showing the start of the sequence. We want to see what caused it.

[Wilberforce]

Thanks all!  I'd been hesitant to turn on EPR full-time because I'd read it might induce central apnea, but I'll take a look. I'll also try disabling ramp and adjusting the pressure.  Attached are two 3-minute screenshots of clear airway events.

   
   

[Wilberforce]

Adding one more segment from earlier in the night, as I realized the others are from around the same time.

   

[Gideon]

EPR,
If that is your belief then never use EPR. The only reason you don't see CA events during the ramp is because they are there. You do know the reason you don't see CA events during the ramp is because no events are reported. Also never ever use BiLevel because they are like EPR on steroids.

Sorry about that.

On ResMed CPAPs and APAPs EPR is your best treatment for hypopneas, flow limits and RERAS. Can EPR cause CA events, yes. You do know that simply using a CPAP can cause Central events, and so can a simple, basic, pressure increase. What causes these CA events? It is actually the fact that you are breathing better and as a result you have flushed out a bit too much CO2.

Our drive to breathe is not a need for oxygen but rather to remove the byproducts of respiration.

What needs to occur is for you to try EPR and then evaluate the results. If you should get a significant number of central events then, and only then react to what happened and mitigate the situation, often this will be to back off on the parameter that you changed. But small numbers of CSA events are not a problem.

There is too much good to come from the use of EPR not to try it

EPR is that important.