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[Pressure] Difference between EPAP set pressure and operational pressure - Printable Version

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Difference between EPAP set pressure and operational pressure - brugerard - 01-02-2020

Good morning,


I have started my therapy a couple of weeks ago, I am still fine tuning EPAP and IPAP on a Respironics BIPAP Pro and I a have a couple of questions. Overall everything is OK except waking-up rather early in the morning (6 hours per nights). Average AHI of 1.68 over 15 days so not bad  

1) I have just noticed from my OSCAR charts that EPAP operating level is always 1cmH2O over the set-up level (see attached screen capture). Is this normal?

2) I returned last night from a week at sea level to home at 2,400 meters (vicinity of Mexico city so not that cold) and I really struggled with very dry mouth and sinus despite my humidifier. It seems humidifier adaptive mode does not work very well for me, water level did not decrease much.

I really enjoy Apnea Board. Great source of info.   


RE: Difference between EPAP set pressure and operational pressure - Dormeo - 01-02-2020

Congratulations on starting therapy for your apnea! I'm sure the experts here can offer you some guidance about your settings.

But first, could you tweak your chart a little bit so all the important information is visible? Turn off the pie chart (Preferences ... Appearance) and the calendar (little triangle to the left of the date). Then scrunch your graphs a little so that the whole flow rate graph is visible. You can do that by grabbing the gray horizontal bar that separates the graphs.

About the dry mouth: this may not be related to the humidifier but instead reflect mouth breathing. But if your machine has a fixed humidifier setting you can use, you could give that a try.


RE: Difference between EPAP set pressure and operational pressure - Gideon - 01-02-2020

The dryness could also be because of your altitude change of nearly 8000 feet.  As you know the air at altitude is drier/less humid than at sea level.

I would like you to increase your PS to 3.5 to see if the hypopneas will come down a little while keeping an eye on your central apneas.


RE: Difference between EPAP set pressure and operational pressure - brugerard - 01-02-2020

(01-02-2020, 12:43 PM)Dormeo Wrote: Congratulations on starting therapy for your apnea!  I'm sure the experts here can offer you some guidance about your settings.

But first, could you tweak your chart a little bit so all the important information is visible?  Turn off the pie chart (Preferences ... Appearance) and the calendar (little triangle to the left of the date).  Then scrunch your graphs a little so that the whole flow rate graph is visible.  You can do that by grabbing the gray horizontal bar that separates the graphs.

About the dry mouth: this may not be related to the humidifier but instead reflect mouth breathing.  But if your machine has a fixed humidifier setting you can use, you could give that a try.

Thank you Dormeo. Revised chart attached.


RE: Difference between EPAP set pressure and operational pressure - brugerard - 01-02-2020

(01-02-2020, 12:51 PM)bonjour Wrote: The dryness could also be because of your altitude change of nearly 8000 feet.  As you know the air at altitude is drier/less humid than at sea level.

I would like you to increase your PS to 3.5 to see if the hypopneas will come down a little while keeping an eye on your central apneas.

Thank you. I will slightly adjust for an effective PS of 3.5-4 for tonight. My setting for last night was 10/6 so PS of 4 but data showed in reality a operational PS around 3. So my initial question regarding the discrepancy between machine setting and pressure data recorded.


RE: Difference between EPAP set pressure and operational pressure - jaswilliams - 01-02-2020

Make sure you don’t have flex on as that will effect pressure support the wavy green line indicates you have flex on


RE: Difference between EPAP set pressure and operational pressure - brugerard - 01-02-2020

Indeed. Flex is on. I had my first few days without it but I have much more natural breathing feeling with it.


RE: Difference between EPAP set pressure and operational pressure - Gideon - 01-02-2020

Your PS is limited by your Max IPAP of 10, set your IPAP Max to 14 to give yourself room to apply the PS


RE: Difference between EPAP set pressure and operational pressure - brugerard - 01-02-2020

(01-02-2020, 06:27 PM)bonjour Wrote: Your PS is limited by your Max IPAP of 10,  set your IPAP Max to 14 to give yourself room to apply the PS

I am afraid I have the wrong machine for that. Fixed IPAP with Respironic BiPAP pro so no max level... Just a fixed IPAP level