Comparison of Visual Assessment and Hemolysis Index in Detecting Hemolysis across Common Biochemical Assay: Implications for Sample Rejection in Clinical Laboratory Practice.

Abstract

Introduction: Hemolysis is a common preanalytical interference in clinical laboratories, affecting up to 4% of blood samples. It can significantly impact the accuracy of test results, potentially leading to misdiagnosis and inappropriate treatment.

Objective: To quantify the effects of hemolysis on routine clinical biochemistry parameters by comparing visual assessment with machine-based hemolysis indices (HIs).

Methodology: This cross-sectional study was conducted at AIIMS, Kalyani, from 2021 to 2023. Residual serum samples were used to assess the impact of mechanically induced hemolysis on 40 biochemical parameters measured using a Vitros 4600 analyzer. A semiquantitative visual grading scale was developed and compared to the analyzer's quantitative HI thresholds. Discrepancies in sample rejection rates between visual and automated methods were analyzed using the hospital's electronic health record database.

Statistical analysis: Data analysis included calculating rejection rates and comparing differences between visual and HI-based methods for each analyte.

Results: Visual assessment categorized most samples as "no hemolysis" (91.86%-100%), with mild hemolysis (1.43%-9.09%) being common and severe hemolysis (0.41%-0.62%) rare. HI-based detection showed higher rejection rates for analytes such as potassium (1.58% higher), phosphate (1.07%), and liver enzymes. Conversely, lower rejection rates were observed for creatinine (+0.75%), urea (+0.79%), and electrolytes. Discrepancies exceeding 0.5% were noted for frequently tested analytes, raising the concerns about the reliability of visual assessment for specific parameters.

Conclusion: Optimizing hemolysis assessment protocols by aligning HI thresholds with analytical sensitivity and clinical needs shows promise for improving laboratory result accuracy and patient care.