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

Abstract

Riassunto La presenza di emolisi in un campione biologico è causata principalmente da anemia emolitica o emolisi in vitro. La seconda circostanza è conseguente ad attività inappropriate per la raccolta e il trattamento del campione biologico che possono inficiare l'attendibilità dei risultati di molti esami di laboratorio. L'emolisi è valutabile mediante la determinazione dell'emoglobina libera, il cui limite è 20 mg/L nel plasma e 50 mg/L nel siero. L'emolisi si rende visivamente palese quando la concentrazione di emoglobina libera supera 300 mg/L. Poiché i campioni emolizzati sono la causa più frequente di non conformità dei campioni biologici nei laboratori clinici, con prevalenza prossima al 3% di tutti i campioni ricevuti, queste raccomandazioni di consenso sono state redatte specificatamente per assistere i professionisti di laboratorio nella rilevazione e gestione dei campioni emolitici. In sintesi, l'approccio raccomandato si basa su: (i) rilevazione e quantificazione sistematica dell'emolisi mediante ispezione visiva e successiva determinazione dell'indice di emolisi in tutti i campioni con emolisi visibile; (ii) immediata notifica al reparto della presenza di emolisi del campione secondo modalità definite localmente; (iii) soppressione di tutti i test influenzati dalla presenza e/o grado di emolisi; (iv) richiesta tempestiva di un secondo campione sul quale eseguire gli esami precedentemente soppressi.

A collaborative study by the Working Group on Hemostasis and Thrombosis of the Italian Society of Clinical Biochemistry and Clinical Molecular Biology (SIBioC) on the interference of haemolysis on five routine blood coagulation tests by evaluation of 269 paired haemolysed/non-haemolysed samples

“…After the delivery of all frozen aliquots to the reference laboratory, the thawed plasma, previously evaluated at the collection site, was visually re-evaluated by two independent laboratory technicians. The sample hue was compared with a predefined photographic colour scale in 9 ranks, on the basis of predefined quantities of free haemoglobin (fHb) added to clear plasma, as published by Lippi et al ( 11 ). In the attempt to correlate the visual colour scale to an instrumental measure, the haemolysis degree was ranked in 9 different classes, similar to Lippi et al ( Table 1 ), from no haemolysis ( i.e., ≤ 0.05 g/L of fHb) up to gross haemolysis ( i.e.…”

Biliary acids is a critical laboratory value in pregnant women: a case report as an opportunity to improve the quality of care

“…SIBioC-SIMeL-CISMEL Intersociety Study Group on extra-analytical variability of laboratory data also recommends to realize a list of panic values and define criteria for their communication. 40 The main problems in establishing suitable procedures for managing critical values are related to the insufficiency of definitive information to determine the effectiveness of including a parameter in the list of potential critical values and the resulting magnitude of deviation in order to be considered truly critical. The development of a list of critical values consistent with the local laboratory environment and the adoption of an efficient and standardized procedure for reporting critical values is imperative.…”

The degree of acceptability of swine blood values at increasing levels of hemolysis evaluated through visual inspection versus automated quantification

“…The B, C, and D aliquots of each animal’s sample were subjected to a progressively increased level of physical stress (i.e., rotary shaking) to generate a degree of hemolysis that was visually scored as 1+, 2+, or 3+, according to a reference colorimetric scale. 7 The samples were then re-centrifuged and immediately analyzed, and the analytical imprecision (i.e., percent coefficient of variation [CV%], shown in Table 1) of the values for the tested parameters was sufficiently limited to allow testing in a single analytical run rather than in duplicate. The intra-assay imprecision was determined by testing 10 replicates of 1 pool of 10 routine samples in a single analytical run.…”

“…Because of the lack of information about the potential biasing of diagnostic test results by spurious hemolysis, veterinary diagnostic laboratories generally provide warnings about the presence of mild hemolysis in their medical reports, whereas samples with moderate or frank hemolysis are considered unsuitable and are rejected. 7 The method used to assess the content of cell-free hemoglobin in veterinary samples varies among veterinary diagnostic laboratories, but it typically involves using a visual score of 0 to 3+, which follows the current recommendations for evaluating hemolysis in human samples. 7 Notably, hemolysis in samples is a critical issue for experimental studies of farmed and laboratory pigs, in which it is often impossible (at time of slaughter) or ethically questionable (according to the principles of replacement, reduction, and refinement) to repeatedly collect blood from the same individual.…”

“…7 The method used to assess the content of cell-free hemoglobin in veterinary samples varies among veterinary diagnostic laboratories, but it typically involves using a visual score of 0 to 3+, which follows the current recommendations for evaluating hemolysis in human samples. 7 Notably, hemolysis in samples is a critical issue for experimental studies of farmed and laboratory pigs, in which it is often impossible (at time of slaughter) or ethically questionable (according to the principles of replacement, reduction, and refinement) to repeatedly collect blood from the same individual. It is therefore essential to ensure a high degree of sample quality, thus limiting the need to recollect blood from animals.…”