Treating Clogged IJ's

For clearing dialysis catheters (Ash split), our Interventional Radiologists liked a 2-hr infusion of 2-4mg tPA per port (we mixed the 3mg in 50cc NS, so the pt only got 100cc over two hours). They would have preferred to give 5mg per port but we had such poor areas for infusion (Infusion Clinic too busy, PACU sometimes could't take pt) that the IRs reduced the dose. If there was nowhere to send the pt for the infusion, the IRs felt safe with us observing the pt for the two hours in a little holding area just outside the Nurse's Office. We did not draw coags because of the infusion but did draw them just in case the infusion was unsuccessful and a catheter stripping had to be done the next day. Or, if that was unsuccessful, of course, the next day the cath would be pulled and a new one inserted.
Infusion successful most of the time.
Your question was for IJ catheters, though, right?? But then you say the "dialysis nurse would pull it off with next treatment" -- sounds like it's a dialysis cath you're asking about (which is why I gave info on our tx).
Did you ask the new doc for reasoning behind the change? Do you have studies that support the old way? Did he present literature/comparative studies re: new method? He may have some good info.
Meanwhile, how does it "pull an RN out of the loop" for 4 hr? Does pt have to be in a different area from the other dialysis pts? It's such a low-priority infusion, it seems pt could sit w/dialysis pts and be "monitored" there. But then I'm not familiar w/your setup. You might gather literature/studies on your own, and present them to him along with an alternative tx as a compromise, as tying an RN up for 4hr is a strain on personnel/resources (you're not staffed for it). Perhaps there's a middle ground (supported by literature, of course) and hopefully the new doctor is reasonable. Good luck with frustrating problem!