Best practice for locking a central line with heparin.

[kristine_bean, RN]

At our hospital we don't usually lock piccs with heparin but occasionally we have picc lines that have different end caps and clamps on the lumens. We were instructed to heparin lock these types as they were prone to clotting. So I have a couple questions

1. Do we always draw the heparin out prior to using the line again. I ask this because the heparin doesn't just sit in the line, it mixes with blood and when you go to draw it out, blood is immediately what you see. So how can we know how much made it to the patient and what volume of heparin remains in the line? Not to mention the amount inserted is 2.5ml and PICC lines depending on the length only hold 0.5-1ml.

2. With normal saline flushes we do 20cc to flush PICC lines. If it is an IJ which is about half the length of one inserted through the arm, would it be reasonable to flush with only 10cc of saline and then follow it with the heparin?

Thanks a bunch!

[SarHat17, ASN, RN]

First, I'd suggest checking your hospital policies/practices. If you don't find your answer there, or still have questions, talk with your educators and/or manager/PICC RN or team. These are all really good questions that need answered, and I bet there are others who want to know also.

[IVRUS, BSN, RN]

Kristine,

What is the concentration that you are using to "lock" the PICC line?  Standards, and many Policies have you locking catheters with the lowest concentration, namely 10 units/mL.  With this concentration, there is no need to withdraw the heparin that was dwelling in the catheter lumen prior to flushing.  Withdrawing prior to flushing is mandatory, however, on Dialysis Catheters as the concentration used is much greater.