basic IV question.

When an IV cannula is in a vein, you will sometimes get blood return. This doesn't mean it's a 'bad' vein.

Remember veins have tiny valves in them, that close to help the heart pump blood back up into the body, to the lungs for 02 and C02 exchange. So, when a cannula is inserted, it can be a little positional, ie: the tiny valve may not be quite closed, blood escapes, & you see it in your cannula. No blood doesn't mean it's a bad cannula either.

I just flush them and get rid of the blood, which we do every shift anyway to see that our cannulas are patent, and it gets documented (as with PICC'S).

If an IV site isn't red, swollen, etc it is OK for your IV fluids.

Is that what you wanted to know?

Don't always get a blood return for a variety of reasons. As long as there is no s/s of problems with the site, it flushes easily, or the fluids are running without problems, then be happy!

Look in your books or Google for more info!

Best wishes!

Blood return is not the gold standard for a patent IV. Flushing easily with no pain or swelling is. IVs are designed to introduce fluid into the bloodstream, they are not designed to draw blood. We often do that but it is an "off label" use. Some other reasons it might not draw is that the catheter is almost as large as the vein, which occludes the downstream blood flow, or the vein might curve so the cath is pressing on the side of the vein. It can also build a little flap of fibrin at the opening that only allows one way flow. If the vein is surface enough you can also see the wash-out of blood as you flush saline.

Blood pressure also can be a factor. Flush with no pain, no 'bulge', no resistance- generally means good to go. :)

Thanks! exactly what i was looking for.!

Thanks for coming back & saying thanks!

Remember, although most of those who posted here are correct in saying that you may not get a blood return, however, that is ONLY true for short term, less than 3 inch IV catheters. ALL catheters that terminate in the central vascular system (SVC) must, and should yield a blood return. (THIS is the GOLD STANDARD!)

Don't know if this site would be helpful but here it is anyway

http://www.ivteam.com/visual-infusion-phlebitis-score/

I think the whole blood return thing comes from the days when IV's were actually heparin locked instead of normal saline. With the hep lock, you nearly always got a good return from what I understand.