Hi. I've been a cpap user for about four years. I use an Airsense 10 autoset now and have been for about a year and also use a full face mask. First, when using the ramp feature, it initially climbs up to the minimum pressure you were prescribed. (mine is set from 10-15 so initially it goes up to 10). From this point the machine will adjust to your needs during the night, raising and lowering the pressure as needed within your prescribed settings. This is the main function of an autoset - it will only use the minimum pressure you need based on your breathing and whether or not you are experiencing an apnea at any given point of your night. When it raises the pressure, it is opening your airway. Once your airway is open, it will maintain that pressure until it is no longer needed, then lower it back down to the minimum setting your doctor prescribed.
As an example - when I mask up, it goes to 10. When I experience an apnea, it may raise it anywhere from 10.1 to 15.0 in order to open my airway. It won't go higher than 15 as that is my prescribed upper pressure. Once my apnea passes it could lower it back down to 10.0 or maintain any pressure between 10-15 in order to maintain my airway. (this is just a simplified explanation)
From your description, is could be that sometimes when you wake up, the pressure could be high due to a mask leak occuring, or you're experiencing an apnea and woke up during it.
At other times when you wake up and feel that the pressure seems lower, it means that you did not need a higher pressure at that particular time.
I suggest you use the resmed "myair" web site. It can give you the basic information on how you did each night; i.e. mask seal, time used, number of apnea events you experienced. Or, you could use a program called "sleepyhead" that is free and available for download on the internet. Sleepyhead will give you very detailed information on each minute of your night using a cpap machine.
I hope this helps, and keep up using your machine. It may take a while, but you will start feeling better, once you get used to using the device.
One more thing....I used to use a nasal mask but started breathing through my mouth while asleep, so I change to a full face mask. I have not had to use a mouthpiece to keep my mouth closed. If you have or continue to have bad leaks with your mask, you may need to try another size cushion or another full face mask. I use the F&P Simplus and the Resmed Airfit F20. They both work for me.....
