Haemolysis: an overview of the leading cause of unsuitable specimens in clinical laboratories

Abstract

Prevention of medical errors is a major goal of healthcare, though healthcare workers themselves have not yet fully accepted or implemented reliable models of system error, and neither has the public. While there is widespread perception that most medical errors arise from an inappropriate or delayed clinical management, the issue of laboratory errors is receiving a great deal of attention due to their impact on the quality and efficiency of laboratory performances and patient safety. Haemolytic specimens are a frequent occurrence in clinical laboratories, and prevalence can be as high as 3.3% of all of the routine samples, accounting for up to 40%-70% of all unsuitable specimens identified, nearly five times higher than other causes, such as insufficient, incorrect and clotted samples. This article focuses on this challenging issue, providing an overview on prevalence and leading causes of in vivo and in vitro haemolysis, and tentative guidelines on identification and management of haemolytic samples in clinical laboratories. This strategy includes continuous education of healthcare personnel, systematic detection/quantification of haemolysis in any sample, immediate clinicians warning on the probability of in vivo haemolysis, registration of non-conformity, completing of tests unaffected by haemolysis and request of a second specimen for those potentially affected.

Preanalytical quality improvement: from dream to reality

“…In vivo hemolysis is one of the leading challenges for clinical laboratories, since it is independent of the technique used for collecting blood and is therefore both virtually unavoidable and potentially insurmountable (27). Conversely, in vitro hemolysis depends mainly on blood collection technique and can also occur due to inappropriate collection, handling, storage and processing of the specimens (28).…”

Multicenter evaluation of the hemolysis index in automated clinical chemistry systems

“…Spurious test results obtained on unsuitable specimens not only impact the quality of the total testing process, but might produce adverse clinical and economic outcomes. Several lines of evidence show that in vitro hemolysis is the most prevalent preanalytical error; its frequency reportedly affecting as many as 3.3% of routine samples referred to the clinical laboratory, and accounting for up to 70% of all the unsuitable specimens received (1)(2)(3)(4)(5)(6)(7). Hemolysis is commonly defined as the release of hemoglobin from erythrocytes into the surrounding plasma as a result of damage or breakdown of the (7).…”

“…Several lines of evidence show that in vitro hemolysis is the most prevalent preanalytical error; its frequency reportedly affecting as many as 3.3% of routine samples referred to the clinical laboratory, and accounting for up to 70% of all the unsuitable specimens received (1)(2)(3)(4)(5)(6)(7). Hemolysis is commonly defined as the release of hemoglobin from erythrocytes into the surrounding plasma as a result of damage or breakdown of the (7). The interference effect from hemolysis in laboratory diagnostics is a consequence of several coexisting biological and analytical causes, including (a) leakage of hemoglobin and other intracellular components into the surrounding fluid thereby producing false elevations of intracellular analytes or dilutional effects, (b) method-and analyte-dependent spectrophotometric interferences and (c) chemical interference in a variety of analytic reactions.…”

“…The interference effect from hemolysis in laboratory diagnostics is a consequence of several coexisting biological and analytical causes, including (a) leakage of hemoglobin and other intracellular components into the surrounding fluid thereby producing false elevations of intracellular analytes or dilutional effects, (b) method-and analyte-dependent spectrophotometric interferences and (c) chemical interference in a variety of analytic reactions. At high concentrations of serum hemoglobin, all these interference effects might coexist, thereby producing spurious variations that do not necessarily follow the same pattern resulting in overestimation or underestimation (1,2,7,8). The magnitude of this problem is further magnified by the management of hemolytic specimens in the laboratory, from their identification to the optimal means of handling them.…”

“…One of the more debated issues is the identification of hemolysis by laboratory personnel, because hemolysis in serum or plasma is undetectable until the specimen has been centrifuged. However, even following centrifugation there are no definitive guidelines, other than recommendations or suggestions, that define what means should be used to assess the degree of hemolysis or what thresholds should be used to guide the rejection of samples (7).…”