Sorry getting there to hear that. I want to say Im not familiar with your dhc dose but 25mcgs isnt alot of fent to begin with and not having any clue as to when you upped the dose from 12 to 25 again I can only say this, make sure your patch is making good contact and that it in fact has med in it and hasnt sprung a leak(had this happen once) and if all thats good I would guess it just taking time to get those levels of fent up in your system.
The patches are on of those things that take time to get to a theraputic level and begin to work adequately if its going to. Thank goodness your Doc was one of those that understands this and didnt take away your dhc immediately following your increase in fent.
I know this isnt alot of help when your in pain and I know the holidays being here are going to make getting ahold of your Doc difficultif not impossible for a few more days so if you can hang in there you should see some relief by at least tomorrow if all else fails you can go the horrid way of the dreaded ER.
Wishing you luck and pain free days soon.