Blood draws from central lines with TPN infusing.....
Our current policy is to stop the infusion, flush with 20ml NaCl, draw a waste and discard 3-5ml blood, then draw sample followed by a NaCl flush and restart of the infusion as ordered. That being said, we have had some questioning from the lab personnel regarding concern for altered lab results based on this practice. I do not know of any actual altered lab results if the practice is followed as stated above. In my opinion, the time it takes from shutting off the infusion, obtaining the materials to do this process and completing it from initial flush to discard of waste should more than allow for the TPN to dissipate within the SVC. I truly feel that saving the patient these multiple lab draws peripherally would be the preferred method. I have a few questions:
1. What is everyone's practice with regards to single lumen PICC lines with TPN infusion and lab draw results?
2. What is everyone's practice with regards to multi-lumen lines with TPN infusing and lab draw results?
3. Is there a certain length of time the TPN must be on hold prior to carrying out the above sequence of events?
4. The lab personnel have stated concern about the TPN having leached onto the internal lumen and therefore it may alter lab results even with the above stated practice. Does anyone have any experience with this being an issue?
5. Lastly, WHY? Is there any evidence based practice to support the argument that the above mentioned practice is not only OK but that it does not alter lab results if properly flushed, waste discarded, etc.? Where can I find that evidence?
Thank you to anyone that can take the time to reply. I have read the older posts on this issue but could really use some actual references for the practice so that we can get everyone in our facility on the same page as to how we provide patient care.