Any catheter that is centrally placed (tip in SVC) should yield a blood return upon gentle aspiration of the syringe. However, if it is a PICC, that catheter should be a 4 French or greater as the 3 French's inner lumen is such that it doesn't yield a blood return very easily. Remember as well that one should use slow, gentle aspiration of the syringe barrel in order to obtain that return so the catheter doesn't collapse. If a centrally placed catheter won't yield a return try some nursing interventions such as: 1. Have the pt turn his or her head and cough. 2. As long as it isn't contraindicated, have them take a deep breath and hold it. This increase in vascular pressure will sometimes free a catheter as it sucking up the vein wall. 3. Reposition a pt. ie, if they are lying on their side, have them lie on their back. 4. Raise the arm on the side that the catheter is in.
Failure to get a blood return from a central catheter is a real problem.
In the case of a Triple Lumen Catheter, each lumen should yield a return as each on exits into the vascular system at a different spot. When a catheter doesn't yield a return it may have a fibrinous tail or fibrin accumulation covering the exit site of that lumen. This fibrin is a mixture of formed blood elements, immunoglobulins etc. Fibrin development is inevitable, but you don't want it there. You may be able to infuse, but negative aspiration doesn't give you a return. This fibrin is a precurser to bacterial colonization and thrombus.
The lumen that won't yield needs Alteplase (cathflo) to be instilled in it to restore patency.