ummm some of the above information is correct, some not so accurate. i left ICU and was a dialysis nurse for about 5 years.
First, IJ's are a central line like PICC's, subclavians or femoral lines. yes there are 2 ports marked V and A, but it's in the same vessel. The V and A are more likely indicative of the where the other end of the catheter lumen lie in the vessel itself, distal or proximal. It is used to hook the patient to the machine. 'A' being the line used to withdraw the blood from the patient to feed the machine and 'V' used for its return.
2nd: the lines are heparinized with a more concentrated heparin solution to ensure their patency. Dialysis nurses and docs are EXTREMELY territorial when it comes to their lines. we didn't want people messing with them because they were essentially the patient's lifeline and their only means of dialysis access. Nephrologists don't place lines and must rely on someone else to put them in. that's a pain in the butt and slows us down. a 4 hours treatment is really about 6 hours to the nurse doing it cuz they have to warm up the machine, test it and then disinfected it after the treatment. better no one uses our line.
3rd: a dialysis line CAN be used for med administration, provided you pull the heparin out of it, 10 cc waste is usual, and block it again with heparn when done. we'd prefer if you don't use it for routine med administration but in an emergency or no other options availabe it is a viable route. refer to #2.
4th: a fistula may or may not be accessible depending on it's blood flow and maturity. it's usual to place a line in as the fistula develops and matures. it's not uncommon to try sticking it and see what happens. sometimes it collapses, sometimes it's flow is not enough to sustain the machine, sometimes you pull from it and return to the line. using it will eventually make it stronger.
5th: your suggestion of an alternative route and opening a discussion with the doc should in no way make you feel like an idiot! i'd worry more if you tried to fake it. docs and your co-workers will appreciate your conscientiousness. it show you were thinking and your confidence in your knowledge base to ask in the first place. you were your patient's advocate. good job!
6th: nursing is an ongoing learning process. when you are unwilling to continue leaning, it's time to get out!
hope this helps. :heartbeat