Assessing the Reliability of Arterial Blood Gas Analyzer for Sodium and Potassium Measurement in Critical Care...

Critically ill patients often experience fluid and electrolyte imbalances, often due to medical conditions or medications. Therefore, evaluating serum electrolyte levels is crucial in managing these patients. This study is aimed at assessing the arterial blood gas analyzer's accuracy in measuring serum electrolytes at the Emergency Treatment Unit (ETU) of Teaching Hospital Karapitiya (THK), Galle. This cross-sectional study was conducted with 67 ETU, THK, patients, and their sodium (Na⁺) and potassium (K⁺) levels were measured using both ABG and ISE analyzers. The study examined the correlation between the two methods for Na⁺ and K⁺ and assessed the validity of the ABG analyzer through t-tests. Additionally, the clinical significance of these methods was evaluated using Cohen's d effect size (ES) values. The mean Na⁺ value was 130.87 ± 9.522 mmol/L for the ABG analyzer and 130.30 ± 8.753 mmol/L for the ISE analyzer. The K⁺ values were 3.80 ± 1.055 and 3.93 ± 0.835 mmol/L, respectively. The correlation coefficients between the two methods were 0.875 for Na⁺ values and 0.905 for K⁺ values. p values were 0.275 and 0.024, respectively. The ES value for Na⁺ values measured using ABG and ISE was 0.062, and for K⁺, it was 0.157. The Na⁺ concentrations exhibited no statistically significant difference, while K⁺ concentrations demonstrated statistical significance. However, the observed disparities in the concentrations of both parameters were of limited clinical significance. Clinicians can confidently rely on the ABG analyzer as a dependable tool for measuring Na⁺ and K⁺ values in the management of critically ill patients.