Hemolysis detection and management of hemolyzed specimens

Assay interferences have long been underestimated and unfortunately too often undetected in the daily clinical laboratory practice. The extra-analytical phase of the laboratory testing process has been recognized as the major source of laboratory errors over the past decade. Preanalytical errors are most common errors within the total testing process and hemolysis is recognized as one of the most prevalent preanalytical errors and surely the most prevalent interference in clinical laboratory testing. Visual detection of hemolysis is arbitrary and therefore mostly unreliable since it may over- and underestimate the actual prevalence of hemolyzed serum specimens (i.e., trained observers are unable to accurately rank the degree of interference in serum). Elevated concentration of bilirubin may further impair the ability to detect hemolysis by visual inspection and therefore lead to serious underestimation of hemolysis in neonatal samples where elevated bilirubin concentration is commonplace. The recent advances in laboratory technology have lead to an increasing trend in the automation of various preanalytical processes into large preanalytical modules. Such modules as well as novel automated laboratory analyzers offer the automated detection of serum indices. This is advantageous due to the increased reproducibility and the improvement in detection of mildly hemolyzed specimens (serum hemoglobin < 0.6 g/L). These platforms commonly use the semiquantitative spectrophotometric measurement and grade interfering substances into several categories. However, various analytical platforms may have different decision thresholds for various serum indices. Moreover, different systems might be different in their assay parameters and the degree of the interference of the specific interfering substance. Therefore, more efforts should be focused to standardize the mean of reporting the hemolysis index, especially when this important parameter is used for obtaining meaningful information on the quality of sample collection throughout collection centers and wards. Hemolysis is still one of the biggest challenges to the laboratory specialists. In case of hemolysis, laboratory personnel should always ask for new sample(s). In case new sample(s) can not be obtained, it is the responsibility of the laboratory specialist to communicate the problem with the physician responsible for the patient and seek for the solution to the best of the patient care