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

The presence of haemolysis in a biological blood sample is mainly a result of haemolytic anaemia or haemolysis in vitro. Another cause may be inappropriate handling at the time of collection and processing of the sample, and this may affect the reliability of the test results. Haemolysis is assessed by quantification of free haemoglobin, whose limit is 20 mg/l in plasma and 50 mg/l in serum. Haemolysis can be observed visually when the concentration of free haemoglobin exceeds 300 mg/l. Since haemolysis is the most frequent reason for a biological sample to be considered unsuitable for processing in the clinical laboratory, with a prevalence approaching 3% of all samples received, these consensus recommendations have been drafted specifically to assist laboratory professionals in the detection and management of haemolysed specimens. The recommended approach can be summarized as follows: (1) systematic detection and quantification of haemolysis by visual inspection and subsequent quantification of the haemolysis index in all samples with visually detectable haemolysis; (2) immediate notification to the referring department of the presence of haemolysis in the sample, as locally determined; (3) suspension of all tests affected by the presence and/or the degree of haemolysis detected; and (4) timely request for a second sample to allow the tests previously suspended to be performed.