The majority of detected clinical laboratory errors originate in the preanalytic phase of testing. Hemolysis is one of the most prevalent preanalytic errors, often leading to rejected samples because of interference.
Hemolysis influences the accuracy and reliability of routine chemistry testing by two different mechanisms. The first is through the release of analytes found in high concentrations in erythrocytes; the second is through interference from hemoglobin itself.
Traditionally, hemolysis was detected by visual inspection of serum or plasma. Specimens with a light pink hue indicate slight hemolysis, whereas a deep red colour represent gross hemolysis. This visual assessment of the degree of hemolysis can be highly subjective and unreliable.
Fortunately, serum indices on contemporary chemistry analyzers enable automated semi-quantitative assessments of hemolysis, icterus, and lipemia, thereby significantly improving the process for assessing specimen integrity.
Assay manufacturers provide instrument- and test-specific HI (hemolysis index) limits for interference in their instructions for use. Laboratories can use middleware rules to set and customize serum HI thresholds for each analyte. This enables laboratory technologists to readily identify specimens with clinically significant interferences prevent autoverification of results, and intervene as needed.