A introducer is disclosed that includes an introducer sheath for introducing a catheter into a blood vessel at an insertion point, a plurality of electrodes on the introducer sheath, a flush line coupled to the introducer sheath including a proximal end and a distal end. In addition, the introducer includes an impedance assessment unit coupled to the flush line between the proximal end and the distal end and electrically coupled to the electrodes. The impedance assessment unit is configured to inject a predetermined current or voltage into a first of the plurality of electrodes and measure a resulting voltage or current, respectively, from a second of the plurality of electrodes.