Getting Sample Hemolysis Under Control

Hemolysis has been cited as the most common cause of preanalytical error. How can sample hemolysis be avoided? A: Many variables contribute to the ability to obtain a high quality, non-hemolyzed blood sample. Controlling the flow of blood between the vein and the tube is really the basis of a good sample collection. Factors that influence the flow of blood include needle gauge, force of suction, size and quality of the vein, and the device used for collection. Direct transfer into vacutainer tubes will control the flow from the needle into the tube, minimizing hemolysis during transfer. When drawing blood into a syringe, the force of suction should be minimal. A good tip is to pull the syringe back and fill it a bit at a time to control the flow. The same goes for transferring from syringes into collection tubes. Allowing the vacutainer to pull the blood into the tube—rather than pushing—maintains appropriate pressure. How should laboratories examine samples to identify hemolysis? Automated hemolysis index measurements on chemistry analyzers are fast and very reliable at detecting the presence—and relative quantification—of hemoglobin in a sample. Compared to visual examination, automation is more sensitive and reproducible in detecting the presence of hemoglobin and distinguishing it from similar colored interferents, such as bilirubin. Significantly, automation also allows direct electronic communication to the laboratory information system.  How hemolyzed is too hemolyzed? Read more here