An arterial line or vascular access device (VAD) is used to provide easy access to a patient's circulatory system for administration of fluids and medications. Occasionally, blood specimens are drawn from a VAD, but phlebotomists are not usually authorized to collect these specimens. However, phlebotomists may sometimes assist when a clinical person is collecting blood from a VAD. If you are present, be certain that the person performing the collection flushes the line with at least 5 mL of saline and the first 5 mL of blood is discarded before collecting the sample. If this procedure is not followed, the specimen may be contaminated with heparin that was used to flush the line or be diluted. This could cause inaccurate test results.