Comparison of hemoglobin, hematocrit, and lactate values measured by bedside blood gas analyzer with laboratory auto-analyzer values and investigation of their correlations in multiple trauma patients

Aim: In this study, we aimed to compare venous Hemoglobin (Hb) and Hematocrit (Hct) values measured by bedside blood gas analyzer with standard laboratory auto-analyzer values in multiple trauma patients and to investigate if lactate level is adequate in this correlation. Methodology: Vascular access was obtained in the antecubital regions of the patients. Simultaneous venous blood samples were drawn, and a blood gas analyzer measured Hb, Hct, and lactate values, and Hb and Hct values were also measured by a laboratory auto-analyzer in the emergency laboratory. The correlation between the values was calculated. In addition, the prediction of laboratory auto-analyzer values from venous blood gas analyzer values was performed using linear regression equations (Regression Equation (y) = a + bx). Results: A total of 51 patients were included in the study. The median difference between peripheral vein laboratory auto-analyzer values and venous blood gas analyzer values was 0.40 g/dL for Hb and 1.10% for Hct. There were high and very high positive correlations between peripheral vein laboratory auto-analyzer values and venous blood gas analyzer values, with correlation coefficients of 0.693 and 0.862 for Hb and Hct, respectively. The correlation coefficient for Hb increased from 0.693 to 0.827 in 26 patients with lactate values below the 2.5 mmol/L cut-off limit. We also measured Hb and Hct by laboratory auto-analyzer and blood gas analyzer from simultaneous femoral artery-sourced samples from 40 patients. The median difference between femoral artery-sourced laboratory auto-analyzer values and femoral artery-sourced blood gas analyzer values was 0.20 g/dL for Hb and 0.80% for Hct. There were very high positive correlations between femoral artery-sourced laboratory auto-analyzer values and arterial blood gas analyzer Hb value and femoral artery-sourced laboratory auto-analyzer and arterial blood gas Hct value with correlation coefficients of 0.949 and 0.851, respectively. Conclusion: In both venous and arterial samples, the differences between the laboratory auto-analyzer and the blood gas analyzer are limited, and the correlations between them are significantly high. Furthermore, the correlation between the venous blood gas auto-analyzer value and the laboratory auto-analyzer value for Hb is even higher when the lactate value is below the 2.5 mmol/L cut-off limit.