[Equipment] ResMed AirSense 10 Autoset Flow Limitation number during Obstructive Apnea events

[mhireche]

Hello,

I have a ResMed Airsense 10 Autoset equipment and I am using Rescan and Oscar softwares to follow up my therapy.
Since several years I have noticed that my machine is reporting correct numbers (between 0 and 0.5) for Hypopnea events (normal), but I have also noticed that for Obstructive Apnea events the Flow Limitation numbers reported by the machine is 0 while I am expecting something between 0.5 and 1. I don't understand that so I asked the question to my DME and to my doctor but they were unable to give me an explanation. I tried to get in touch with ResMed Support Team in France but they told me they cannot handle directly end users (patients) requests.
Is Flow Limitation only applicable to Hypopnea events ? If not then why I don't see a coherent Flow Limitation number during my Obstructive Apneas ?
Thanks in advance for your help.
Best regards,

[SarcasticDave94]

Welcome to the Apnea Board,

There's a weakest to strongest progression in place, from Flow Limits to Hypopnea to Apnea. Hypopnea and Apnea are defined as at least 10 seconds and will have individual, specific event flags. Flow Limits are not timed and are not necessarily individual, specific events. If you look at OSCAR, your flow limit chart can have activity spanning your whole night's sleep session.

Your AutoSet has a great tool that combats the Flow Limits. If the flow limits need addressed, the chart will look like shaggy grass. So to lower these? Raise your minimum pressure to 7 and enable EPR to full time 3. See how that works.

If you'd rather, show us a recent OSCAR shot before you try this edit.

[OpalRose]

mhireche,
It's not likely you'd receive help or an answer from your DME or ResMed.

You'll receive the best response here by posting a Screenshot of your data.
Be sure you have an SD card in your machine. Download the OSCAR software, and then follow the links below in my signature line to guide you.

[Dormeo]

If you zoom in on the flow rate for an obstructive apnea event, you'll see that after you exhale, your flow rate is at zero for ten seconds or longer. In other words, you are not able to start inhaling for your next breath.

If you zoom in on the flow rate for flow limitations, you will see that they flag certain contours in the trace for your inhalation. Often you will see a plateau at the top of the trace, or a bump or a dent, instead of a nice rounded curve. (The algorithm does not pick up all flow limitations, by the way.) These reflect interference with smooth inhalation, most likely due to a little relaxation in the tissues lining your airway. Your inhalation becomes more effortful.

So, the short version is: OA, no inhalation; FL, more effort for inhalation.