CTs with contrast through central lines - page 2
by GardenDove | 10,599 Views | 13 Comments
The head of our radiology informed me that they cannot do CTs with contrast for PEs or of the Aorta through central lines because they have to push 150cc of contrast in 4 seconds, and it apparently causes the tail of the catheter... Read More
- 0Jan 25, '07 by CritterLoverQuote from rnin02i thought that they could use a central line, but to do so they would have to do the contrast slower and change some of the settings on the machine to get accurate results...so they don't like to do it. but it is possible. but i could be wrong and thinking of something else.
iv contrast for non-vascular studies usually can be done this way.
however, if they are trying to visualize arteries (ct angio of head -- or anything else -- ct chest r/o pe), then the contrast has to go at a certain speed, otherwise the test will be non-diagnostic. usually, we referr to these kinds of cts as needing a "power injector." iv contrast for ct abdomen, ct chest non-vascular, etc can be done with hand-injected contrast, or machine-injected with settings adjusted; and can be given through any picc or central line, as long as your facility allows it.
the problems with using a traditional central line and using piccs for tests requiring a power injector are different.
traditional central lines are fairly stiff, but strong. when the contrast is injected through them, it can cause the tip to whip around, possibly damaging the (major) vessels. traditional piccs are soft, but not very strong. the problem here is the very real possibility that the power injector will cause the picc to fracture. (think about it -- if you can't use anything smaller than a 5 or 10 cc syringe [depending on your facility policy] because it may cause the thing to break, what do you think thick contrast injected under high pressure would do?)
bard solved that problem by creating a power picc: strong enough to withstand the power injector, yet still soft enough to not damage vessels. better yet, they actually studied how the power picc reacted to a pressure injector, and found it safe.
i could be very wrong about this, but my understanding isn't that it is unsafe to use a (non-picc) central line for power-injected constrast, but that nobody has proven that it is safe. i believe that the concern that the tip of a tlc could cause damage to the vessel walls is a concern, a theory, more than fact.
that being said, i know that you will find that some facilities use subclavians/ijs with the power injector -- i've worked in one of them.:uhoh21:
i'm not sure, though, why one poster stated that they can't use piccs/central lines for nuc med studies. that is hand-injected, not power injected, and i've never worked anywhere that had that limitation.
- 0Jan 25, '07 by GardenDoveThanks, critter, for the added info. According to our imaging lady who spoke to me, the whip that you get on the central line is dependent on how much of it is in the body. Ours are 20cm, and because of that length, physics causes it to thrash, much like a garden hose, with the force of the power injecter. She said an IJ is allowed because it has a shorter catheter inside the body.
- 0Jan 25, '07 by TXstudentRNAs I've had MANY PICCs, all but two Power PICC's, I can tell you that they are WONDERFUL for many reasons, but especially with being able to put contrast through them. Some radiology techs would argue with me that they'd have to start a peripheral line and that was one thing I knew for sure wasn't necessary, but since it's still a relatively new concept of using any kind of central line for contrast not everyone is fully aware that it's doable.
I just wanted to clarify one thing though... someone mentioned that they have three ports and one is marked "CT"-- that's not necessarily true. I'm sure they make those, but the ones I've always had are purple with two lumens, one red, one purple. Just wanted to clear that up! But yeah- at my hospital the only time they don't do Power PICCs is if the order is specifically written NOT to. While I love my port I have now, I certainly do miss that aspect of PICCs!
- 0Jan 25, '07 by cardiacRN2006Quote from TXstudentRN
I just wanted to clarify one thing though... someone mentioned that they have three ports and one is marked "CT"-- that's not necessarily true. I'm sure they make those, but the ones I've always had are purple with two lumens, one red, one purple. Just wanted to clear that up!
That's how ours look as well.