TELEpathicRN 127 Posts Mar 20, 2003 Should be pretty safe, have had MD's request us to do this. If the catheter is comepletely clotted, I do what you so, sometimes just with 10 cc syringe, wait until the cath is collapsed, clamp, and then instill the TPA or cathflow activase. Alot of the caths that we instill the activase in are just arterial ports that are sluggish and won't work on the machine ( pillow collapsing, sucking, etc..). We have a few MD's that just can't stand the fact that you have to reverse a catheter!! I don't like to do it, but you do what you gotta do!! One of the docs told me that you aren't doing the pt any good, all you are doing is recirculating the pts blood. Well.... how come when I have had to reverse the lines during an emergency treatment, that the pts K+ level came down from like 6.8 to 5.0 when it was redrawn??