Flow Rate wave form has sharp peaks

[dloomis]

Hi everyone - new PAP user here. I notice that for large parts of my evening my wave form has sharp peak with a steep drop off at exhalation instead of the rounded tops that I've been told is the goal of therapy. What does this wave form show, and if it's abnormal what can I do to remedy it? This is from last night and I feel very rested.

   
   

[Sleeprider]

This is actually a class II flow limitation that your machine is missing for some reason. Your inspiration flow rises sharply from zero then diminishes through the rest of the breath before declining to zero-flow (red line), and becoming expiration. We can quickly solve this by increasing minimum pressure from 6.0 to 7.0, leaving maximum pressure at 11.0 and adding EPR Full-Time at Setting 2 or 3.  Is this flattened or declining inspiration flow typical throughout the night? See the Flow Limitation wiki https://www.apneaboard.com/wiki/index.ph...limitation

[dloomis]

Thanks for the quick reply.

Will setting EPR=2 at 7 cmH2O provide enough expiratory pressure support to prevent mouth leak? I've been struggling with that as a new user and from what I've been reading having high expiratory pressure will help give the soft palate proper support. Thanks again for your insight.

And yes, there are periods where I have perfect rounded wave forms. But these tend to dominate.

[Sleeprider]

Although expiratory pressure will be a bit lower with EPR, it should help, rather than hurt any mouth leaks. With EPR on, pressure will rise during inspiration to provide support where your airway becomes more obstructed with higher inspiratory flow and effort. It should work well for you.

We can work on mouth leaks as a separate issue. If you sleep on your side, try pulling a corner of your pillow between your shoulder and jaw to physically help keep your jaw closed. You can practice speaking while under pressure, and sipping water through a straw. This teaches airway control. It may take a few tries to get it, but eventually the skill in preventing leaks while talking or sipping water can translate to the subconscious sleep state.

[dloomis]

Thank you! I'll change to APAP 7-11 with EPR=2 tonight and will report back with hopefully positive results.

[dloomis]

Although expiratory pressure will be a bit lower with EPR, it should help, rather than hurt any mouth leaks. With EPR on, pressure will rise during inspiration to provide support where your airway becomes more obstructed with higher inspiratory flow and effort.  It should work well for you.

Reporting back after setting EPR=2 with APAP 7-11 per your recommendation. Wave forms look much better! Does this mean I'm a good candidate for bi-level? Or is bi-level only for those on higher pressures? I thought EPR was only a comfort setting; I didn't realize it could help in this way.

P.S. I'm stilling getting consistent flattened peak that the Resmed algorithm either responds to or doesn't. I'm assuming this means I need to titrate higher until this is eliminated.

[Sleeprider]

EPR works in the same way as PS in a bilevel. You have not used the maximum EPR available to you yet. I can show you side-by-side images of the Airsense 10 and Aircurve 10 mask pressures, and the way pressure support is delivered is nearly identical except bilevel allows PS above 3.0 cm. The hardware on your Airsense 11 is identical to the Aircurve 11, and only the firmware is different. I think if we were able to dig deep into the actual logic, that we would find the CPAP is actually a bilevel with limited PS capability. So to answer your question, if you get good results with CPAP, there is no need to spend the money on bilevel. For any continued inspiratory peak flattening, just increase minimum pressure a bit and move to EPR 3.

[dloomis]

Reporting back with some encouraging results. Wave forms look much better at CPAP 9 with EPR 3. 

After starting PAP therapy three weeks ago I mainly struggle with poor wave forms (with arousals) and mouth leak at a variety of pressures from 7 all the way to 11 cm (with EPR usually off). I sometimes get Clear Airway events in Oscar and hardly ever get H, RERA, or OA. Now with EPR maxed out I'm getting good results, but not perfect. I'm titrating down to CPAP 8 EPR 3 tonight to see if my wave forms continue to look good while I reduce mouth leak.

I'm a thin, athletic guy - mid 50s. Always struggled with nasal congestion although I have that somewhat under control with Nasacort. I ordered a V-Com but I doubt boosting my CPAP pressure to > 10cm with that installed will do anything since similar nights at that pressure didn't really help. I really wonder if I have UARS.

Anyway, I'll continue to post updates as I progress.

[Sleeprider]

Hold off on VCom for a bit. It basically counter-acts the pressure support difference you get with EPR. I want you to clearly see it's impact by settling on pressures and EPR first and establishing a baseline.

[dloomis]

Hold off on VCom for a bit. It basically counter-acts the pressure support difference you get with EPR.  I want you to clearly see it's impact by settling on pressures and EPR first and establishing a baseline.

Will do. 

At risk of getting ahead of myself, at what point do I pursue 4cm pressure support per ResMed's titration guidelines, and ultimately get on an AirCurve 10? It's very possible I get zero obstructive apneas or hyponeas tonight at 8cm CPAP on EPR 3, but still get flattened waveforms at that level.