Hemolytic Interference on Blood Gas Analysis

Abstract

Background: Hemolysis is an important preanalytical factor that influences laboratory test results. Because arterial blood gas analysis (ABGA) is performed using whole blood, it is difficult to visually check whether a specimen is hemolyzed, and even blood gas analyzers cannot detect hemolysis. However, there is insufficient consensus on the parameters that are influenced by hemolyzed specimens. This study aimed to determine the effect of hemolysis on ABGA results. Methods: One hundred residual arterial blood specimens were collected from Severance Hospital between March and April 2022. Samples were aliquoted into three groups for mechanical hemolysis. Hemolysis was induced using 16-, 22-, and 26-gauge needles and measured using the Profile pHOx Ultra Blood Gas Analyzer (Nova Biomedical, USA). The remaining blood was centrifuged, and the hemolysis index was determined using the plasma. Results: Among the parameters, pH and K increased, whereas pCO2, Na, Ca2+, and HCO3− decreased. The values of Hb, Mg2+, and Hct did not change with the degree of hemolysis, although there was a difference between the two groups. The values of pCO2, Hb, K, and Ca2+ increased as the degree of hemolysis increased, with % biases exceeding the desirable bias. Conclusions: This study confirmed that hemolysis significantly influences pH, pCO2, and K. Therefore, when clinical findings and blood gas analysis results are inconsistent, clinicians should be cautious of spurious hemolysis when interpreting the results.