Patient Blood Management: Mixing Versus Discard Methods for Central Venous Catheter Blood Specimen Collection

A quasi-experimental study comparing the mixing and discard methods of laboratory specimen techniques in an adult acute care setting was conducted over a 30-month period. Primary end points were delta hemoglobin (Hgb) and transfusion rates. Secondary end points were redraws related to hemolysis and erroneous results, noting central venous access device (CVAD) type. Primary objectives included the comparison of hospital-acquired anemia and transfusion rates utilizing Hgb and venous sampling methods as part of a patient blood management (PBM) program. Secondary objectives tracked the type of CVAD used to acquire venous specimens and the impact on hemolysis rates or erroneous results. Considerations include exploring the benefits of utilizing the mixing method related to cost savings. In summary, the mixing versus discard method eliminates wasting blood to reduce hospital-acquired anemia as part of a PBM program. CVAD type did not influence hemolysis rates or impact erroneous results. The mixing method is easy to implement in any health care setting. Cost savings are feasible by elimination of external venous or arterial blood management protection devices. Removal of add-on devices supports standards by decreasing access points to reduce infection risk. Results, although inconclusive to superiority, demonstrated noninferiority and encouraged consideration of the mixing method for laboratory specimen collection.