We're having an ongoing discussion in our hospital regarding appropriate practice specific to drawing vanco and/or coags from a single lumen PICC, through which vanco and/or heparin is being instilled or infused. Though we've noted several comments regarding opinions as to whether or not this is best practice, we're looking for reference information to assist us in policy updates. Recently, we've cared for 2 patients who arrived with PICC lines placed in other hospitals, and both reported having dual lumen PICC's inserted so that coags and/or vanco levels were not being drawn through the infusion port. Our current practice allows infusion and drawing from a single lumen with adequate flushing before the draw. Does anyone have reference material to share with us? Thanks for your help.