Mike, I have personally been there when I blew a hole through my kidney and pieces were floating in my urinary tact that blocked flow through by bladder. I had a catheter there for about a week. I was fortunate to be allowed to play my pocket trumpet from my ICU bed (mute inserted of course) and all went well.
HOWEVER with that said I witnessed the darnedest thing. When I remained playing within the staff, my catheter drip rate into the bag remained essentially unchanged. However, when I started playing above the staff the drip rate would decrease. So I tried playing around the C above staff, the urine output essentially stopped. That is when my nurse (a male nurse) started getting concerned. He didn't seem to mind in between the range of the staff and high C as he didn't have to come into the room as often to empty my bag. I actually "published" these results on TrumpetMaster at the time I was conducting this "experiment" . Also did an experiment while attached to an oximeter on circular breathing, but reporting on that is for another thread.
Bottom line, physiologically speaking, you won't piss anyone off if you continually play above high C!