Our lab recently announced that they were requiring any patient on TPN to be stuck for labs, rather than using a sample obtained from the PICC or other multilumen CVAD. This is a recent departure from a long-standing policy that worked well for many years. I believe it was the result of some nurses using bad technique, producing questionable results. No one ever reported a problem so that we could pin it down. Needless to say several of our PICC patients have become irate at having to be stuck each morning.
I am updating our policy and have researched three or four different sources. They all indicate that all infusions through the line should be interrupted when obtaining blood, but none of them, including the INS Standards of Practice, and INS Policies and Procedures for Infusion Nursing specify a length of time. I think two to three minutes is probably adequate in a vessel with a capacity of 2-2.5 liters per minute blood flow. I know this will vary greatly based on the patient's cardiac output, but I need a number as a guideline.
Once I have an updated policy firmly supported by science, I will hop on my horse and take on the lab. Thanks for your help.
Jerry Bartholomew RN BSN CRNI
Vascular Access Specialist
Veterans Affairs Medical Center
Spokane, Washington
