Hi Pegm,
Just one more suggestion.
I'm also an ICU nurse and in that setting, for the last couple of years we routinely flush our feeding tubes every 4 hours with 20 mL of tap water. It definitely helps prevent clogging.
And the high blood sugars could well be just from the high sugar feeds. We find these days that almost all of our patients receiving enteral feeding also require insulin! These patients aren't diabetic and their blood sugars return to normal when the feeds are stopped. I wonder if the doctors will ever figure out a better regime of feeds!
Good luck Pegm.

Rosebud