Evaluation of analytical performance of blood gases, electrolytes, and metabolites in critical care using the blood gas analyzer cartridge-electrochemical principle.

INTRODUCTION

Rapid assessment of blood gases, electrolytes, and metabolites is crucial in critical care settings. This study evaluates the performance and interchangeability of a portable blood gas analyser that operates on the cartridge-electrochemical principle.

MATERIALS AND

METHODS

This prospective study evaluates the precision of this analyser, which uses an electrochemical sensor within single-use cartridges. We compare its performance to that of a cartridge-based sandwich sensor cassette; the blood gas analyser used in intensive care units (ICU). A total of forty arterial blood samples were collected between July and November 2024. Performance was statistically assessed using Passing-Bablok regression, Bland-Altman plots, and the Intraclass Correlation Coefficient (ICC).

RESULTS

The blood gas analysis using the electrochemical sensor method demonstrated excellent within-run imprecision (CV%<5%) across all evaluated analytes, with total imprecision consistent with the manufacturer's specifications. Method comparison revealed a strong correlation (ICC>0.9) and agreement for most parameters between the two methods, including pH, partial pressure of carbon dioxide (pCO2), sodium (Na+), potassium (K+), chloride (Cl-), glucose, and lactate. However, Bland Altman showed a systematic bias of 9 mmHg in partial pressure of oxygen (pO2) and 0.02mmol/L in ionised calcium (iCa2+).

CONCLUSION

The analyser using the electrochemical sensor provides reliable performance for blood gases and biochemical analytes, with strong agreement with the cartridge-based sandwich sensor cassette principle. Nonetheless, caution is advised for pO2 and iCa0 measurements due to observed bias, highlighting the importance of awareness of method-specific differences between analysers in clinical interpretation.