A question has come up regarding the drawing of a Vancomycin Trough from a central line into which the Patient was getting his Vanco doses. This nurse felt that some Vanco might still be in the line and would interfere with and make the Vanco Trough level higher.
If the central line is a double lumen, the blood can be withdrawn from the lumen not used for Vanco, but if the line is a single lumen - what are some of you doing? What is your policy & procedure?
Are you flushing the single-lumen central line with Normal Saline 10 mls, and drawing back at least 5 mls blood into the syringe for discard, then drawing the labs using a vacutainer or syringe, and then flusihing the line afterwards with N/S 20 mls, followed by Heparin, as needed?
 If the single lumen line is flushed properly before and after blood draw,with appropriate blood for discard -  do you think this is acceptable?
 One nurse told me that some doctors only want a "peripheral" Vanco Trough level when there is only a single-lumen central line. Our policy here at work is "no drug levels from lumens that were infused with that drug unless ordered by a physician.
What are you all doing/seeing out there in your Infusion practice? Thanks, Wendie S-M