Performance evaluation of the i-Smart 300E cartridge for point-of-care electrolyte measurement in serum and plasma

Background: Electrolytes are measured regularly in a variety of clinical settings because electrolyte imbalance can be life-threatening. Although arterial blood-gas analysis reports electrolyte levels, the result often is discrepant with results from serum and plasma samples. Since prompt and accurate measurement of serum electrolyte levels could allow early treatment, point-of-care (POC) electrolyte analyzers would be beneficial. We evaluated a POC electrolyte analyzer cartridge based on the Clinical and Laboratory Standard Institute (CLSI) guidelines. Methods: Precision and linearity were assessed according to the CLSI EP05-A3 and EP06-A guidelines, respectively. A comparison study was conducted with both serum and plasma samples according to the CLSI EP09-A3. For serum, results from the i-Smart 300E analyzer were compared with results from the Nova 8 and i-Smart 30 analyzers. For plasma, results were compared among the i-Smart 300E, Nova 8, i-Smart 30, and Cobas c702 analyzers. Results: Coefficients of variation in the precision analysis were all less than 5%. Linearity assessment demonstrated a coefficient of determination between 0.999 and 1.000 for all analytes. The comparison study showed a high Pearson's correlation coefficient greater than 0.9 for all analytes, instruments, and specimens. Conclusions: The i-Smart 300E demonstrated good analytical performance. Its use could be beneficial in terms of both efficiency and clinical outcome in point-of-care testing (POCT) for electrolyte levels from serum and plasma samples.