Assessing the influence of true hemolysis occurring in patient samples on emergency clinical biochemistry tests...

Hemolysis is one of the most frequent causes of pre-analytical errors in the emergency department (ED), and it can lead to inaccurate blood results and often requires repeat testing. The purpose of the present study was to evaluate the effects of true hemolysis occurring in ED blood samples on routine clinical biochemistry tests using the VITROS^® 5600 Integrated system. A total of 92 pairs of blood samples were collected from 92 ED patients. Each pair of samples included one hemolyzed sample and one successful (non-hemolyzed) redraw from the same patient. A total of 21 common laboratory analytes and the hemolytic index (HI) were examined. The degree of hemolysis (slight, mild, moderate and heavy) was determined based on the HI. A clinically significant difference in one analyte was defined as a difference greater than its Clinical Laboratory Improvement Amendments of 1988 (CLIA'88) total allowable error (TAE) limits. The results demonstrated that the mean differences in 11 serum analytes (unconjugated bilirubin, Ca²⁺, equivalent CO₂, Cl^-, creatinine, glucose, Mg²⁺, phosphorus, Na⁺, urea nitrogen and uric acid) in hemolyzed and non-hemolyzed samples were within their CLIA'88 TAE limits, while the differences in the other 10 analytes [alanine aminotransferase (ALT), albumin (ALB), amylase (AMYL), aspartate aminotransferase (AST), total bilirubin (TBIL), creatine kinase (CK), CK-myocardial band isoenzyme (CK-MB), lactate dehydrogenase (LDH), K⁺ and total protein (TP)] in paired samples in at least one of the four groups were greater than their CLIA'88 TAE limits. These results suggest that hemolysis had a notable impact on ALT, ALB, AMYL, AST, TBIL, CK, CK-MB, LDH, K⁺ and TP levels. Furthermore, for ALT, AMYL, TBIL and TP, wet chemistry methods displayed superior anti-hemolytic ability compared with dry chemistry methods. Notably, a high concentration of AST was less affected by hemolysis.