Reliability of the i-STAT for the determination of blood electrolyte (K+, Na+, and CI-) concentrations in cattle

Abstract

Background: Rapid determination of blood electrolyte concentrations can help determine electrolyte status and delivery of effective volume of electrolyte solutions in field conditions. Objective: To evaluate reliability of the i-STAT, a point-of-care (POC) device, in measuring blood K+, Na+, and CI- concentrations in cattle. Animals: Ninety-eight cattle with various diseases. Methods: In this prospective study, blood samples collected from the jugular vein were processed for determination of K+, Na+, and CI- concentrations in blood and plasma using the i-STAT and auto-analyzer (Cobas C501), respectively. Blood and plasma electrolyte data were subjected to student t-test for comparison, the concordance analysis for agreement, accuracy, and precision, the Passing-Bablok regression and the Bland-Altman plot for reliability, and receiver operating characteristics curves for sensitivity (Se) and specificity (Sp). Results: Plasma concentrations of K+ (4.39 versus 4.2 mmol/L; P