You are due for a new machine, and the most logical replacement would be an Auto CPAP. For a number of reasons, most of us prefer the Resmed Airsense 10 Autoset CPAP. If you have insurance, talk to your supplier about a replacement. Any doctor, not just a sleep specialist, can renew your prescription if needed. If you are not well insured then you can use your existing prescription to source a replacement online. Me have many suppliers in the Supplier list.
We don't now what model your current machine is. Respironics encompasses many different models and series, however 5-years is the normal lifetime, and you're beyond that.
Altitude can significantly affect the settings you need. Auto CPAP can help with that, but if your machine is equipped with a SD card, your first step should be to upload your data to a computer with the current version of
OSCAR, which replaced Sleepyhead several years ago. You can post a couple current charts, and we can see exactly where you stand.
The SD card is filled until full, and then the oldest data is replaced. You probably have up to one or two years of recent use on the SD card. Upload it now.
The SD card can be deleted or re-formatted to FAT 32 anytime. This destroys all data on the card.
Download
OSCAR from this forum at the link top of the page.
Your machine settings can be changed. The best way to do this is to post some charts, which will tell us what machine you have, what the current settings are, and what direction you need to go to optimize.