Determining the Minimum Discard Volume for Central Venous Catheter Blood Draws

This study aimed to determine the minimum discard volume from central venous catheters (CVCs) to avoid dilution or contamination from flush or IV fluids. In 93 adult patients with CVCs, minimum discard volume findings were 9 ml for tunneled and 6 ml for nontunneled catheters. Nurses who obtain samples from CVCs are uniquely positioned to minimize blood loss from sampling.