A comparison of serum sodium levels measured using a colorimetric kit approach and those determined using direct and indirect ion selective electrode techniques- in a Hospital Central Lab

Abstract

When electrolyte imbalances are not recognized, they are known to cause severe morbidity and mortality. Dyselectrolytemia is frequently curable. Hyponatremia is a common symptom seen in the elderly. Laboratory equipment may be lacking in rural healthcare settings. As a result, the purpose of this study was to investigate the feasibility of developing a screening technique that can aid in the detection of hyponatremia in such facilities. Serum sodium levels in 120 samples were determined by direct, indirect, and colorimetric ISE. SPSS version 17, NCSS 11, and MINITAB 18 software were used for statistical analysis. Statistical significance was defined as a p-value of 0.05. While comparing the instruments, a basic linear regression analysis was performed, and a regression equation for sodium levels was established. The Bland-Altman analysis yielded a 95% agreement limit between the instruments, which is well within the CLIA-recommended target value of 4 mmol/L in the hyponatremic and normonatremic ranges. The resulting regression equation computes a predicted value for direct and indirect ISE using the colorimeter readings, making it similar to all three instruments in the hyponatremic and normonatremic ranges. The colorimetric method can be used as a low-cost screening technique to identify hyponatremic elderly people for whom a tertiary hospital may be inaccessible, allowing for early care.