Air pressure falls below minimum

Just started to use an APAP machine -- ResMed AirSense 10 -- after 5 years of being on a CPAP machine. Noticed that the air pressure falls (rather consistently throughout the night) below the preset minimum of 10 cm occasionally showing 6, 7 up to 9... cm. In all other respects, the machine seems to work fine. To me this is abnormal: the minimum is expected to be just that -- the minimum. I would greatly appreciate your thoughts on that.

Are you using exhale relief (EPR) and if so at what setting?
What mode of operation are you using...exactly what are ALL the settings?
Do you know how to go into the clinical setup menu are to verify all the settings?
https://sleep.tnet.com/home/files/resme ... -guide.pdf
What software are you using that is showing you the drop in the minimum?
Can you share an image of what you are seeing so that we can see what you are seeing?
https://sleep.tnet.com/reference/tips/imgur

If you have EPE set at 3, the pressure is reduced by that amount during exhale. If your setting for Minimum is at 10 and you are inhaling at 10, with a EPR of 3 you would be exhaling at 7 regardless of your minimum setting.

Exhale relief (EPR) = 3
What mode of operation = APAP
RAMP = 5 cm for 10 minutes (am going to set it to OFF, just don't need it)
Software used = SleepyHead
Yes, I have the clinical setup menu
Will prepare the image a little later, though the pressure change is detectable when you move the vertical line reflecting the pressure changes along the graph.

Pugsy, I want to use this opportunity to THANK YOU immensely for the invaluable help you offered me over 5 years ago. It was like a lifeline for me at the time of despair -- no sleep, huge AHIs, totally ignorant Dr., anxiety and, finally, depression. All this, no doubt, attributed to my CPAP experience. You don't even know what support it was! I wanted to send you a note before, so I am doing it know. Thank you!..

Pugsy wrote:Are you using exhale relief (EPR) and if so at what setting?
What mode of operation are you using...exactly what are ALL the settings?
Do you know how to go into the clinical setup menu are to verify all the settings?
https://sleep.tnet.com/home/files/resme ... -guide.pdf
What software are you using that is showing you the drop in the minimum?
Can you share an image of what you are seeing so that we can see what you are seeing?
https://sleep.tnet.com/reference/tips/imgur

Exhale relief (EPR) = 3
What mode of operation = APAP
RAMP = 5 cm for 10 minutes (am going to set it to OFF, just don't need it)
Software used = SleepyHead
Yes, I have the clinical setup menu
Will prepare the image a little later, though the pressure change is detectable when you move the vertical line reflecting the pressure changes along the graph.

Pugsy, I want to use this opportunity to THANK YOU immensely for the invaluable help you offered me over 5 years ago. It was like a lifeline for me at the time of despair -- no sleep, huge AHIs, totally ignorant Dr., anxiety and, finally, depression. All this, no doubt, attributed to my CPAP experience. You don't even know what support it was! I wanted to send you a note before, so I am doing it know. Thank you!..

Using the ramp and EPR is what is causing SleepyHead to record the minimum being so low.
Ignore it or turn ramp off if you don't need it.

With the minimum set to 10 and EPR to 3 then during exhale the pressure will drop to 7 and that will be the "new" minimum pressure per SH's minimum.

Mainly it is the ramp thing making things whacky. When you start at 5 cm then even with EPR at 3 it can only drop to 4 and while it increases up to 10 fairly quickly the ramp numbers are throwing off your minimum averages.