Raccomandazioni di consenso SIBioC-SIMeL per la rilevazione e gestione dei campioni emolisati e utilizzo dell’indice di emolisi

The presence of hemolysis in a biological blood sample is mainly caused by hemolytic anemia or hemolysis in vitro. The latter is caused by inappropriate collection and processing of biological samples, which may affect the reliability of test results. Hemolysis is assessed by free hemoglobin quantification, whose limit is 0.02 g/L in plasma and 0.05 g/L in serum, and visually observed when the concentration of free hemoglobin exceeds 0.30 g/L. Since hemolysis is the most frequent cause of unsuitable biological samples in clinical laboratories, with a prevalence approaching 3% of all received samples, these recommendations have been drafted specifically to assist laboratory professionals in detection and management of hemolysed specimens. In summary, the recommended approach is based on: (i) systematic detection and quantification of hemolysis, by visual inspection and subsequent quantification of the hemolysis index on all samples with visually detectable hemolysis; (ii) immediate notification to the referring department of the presence of hemolysis in the sample, as locally determined; (iii) suppression of all results affected by the presence and/or degree of hemolysis; and (iv) timely request of a second sample, on which the previously deleted tests can be performed.