drastic jump in events per night

Hi. I have been on CPAP therapy for about 2.5 years. I've had a nasal mask almost all that time. About 3 weeks ago I came down with a horrible viral infection and was very congested and couldn't breathe through the nasal mask. So I purchased a full face mask to see that could help me get some sleep with therapy.

I've noticed with the full mask that my events per hour have dramatically increased. I was averaging maybe 1-5 per hour on the nasal mask but with the full face mask my events have jumped to 33 - 58 per hour.

Any ideas on what may have happened? I'm sure it could be the cold/infection that is causing issues but I'm also wondering if I need to increase the airflow for the full mask vs what I had for the nasal.

Any suggestions or feedback you have would be helpful.

Thanks!

If you have a machine that can provide some feedback in numbers, did you change the mask type on your machine to full face type? If not, the numbers may be skewed. If you did make the change to your menu, what was your leak rate? If the full face mask leaks horribly, the PAP machine won't be able to compensate for the leak and all your positive air pressure therapy will go blowing out with the leaks.

Some people's obstruction becomes much worse when they move from a nasal mask to a full face mask. I have seen this happen a number of times while titrating people. One possible explanation for this is something which is known in sleep tech circles as the "reverse MAS effect". This hypothesises that the full face mask presses on your lower jaw which in turn presses on your airway and thus increases the collapse. Increasing the pressure should correct it, but the question becomes whether the pressure increase makes it too uncomfortable to use. By the way, as far as I am aware changing the mask type only changes the level of intentional leak which the machine expects to see.