Clinical Evaluation of a New Point-of-Care System for Chemistry Panel Testing

Abstract

Background: GEM Premier ChemSTAT™ is a point-of-care (POC) system that measures Na+, K+, Ca++, Cl−, glucose, hematocrit, creatinine, blood urea nitrogen (BUN), tCO2, pH, pCO2, and lactate from a single whole blood specimen, providing rapid results in POC settings such as the emergency department (ED). Accurate measurements of creatinine in whole blood and reporting of estimated glomerular filtration rate (eGFR) can minimize adverse effects of contrast-induced nephropathy. Methods: Heparinized whole blood specimens from the ED were analyzed on the ChemSTAT by POC staff. Method comparison was performed against the cobas Integra c501 for creatinine, BUN, and tCO2, and against the GEM Premier 4000 for all other analytes. Precision was conducted with whole blood specimens assayed in triplicate over 6 days. Creatinine results from whole blood and plasma were used for eGFR, by isotope dilution mass spectrometry-traceable Modification of Diet in Renal Disease and Chronic Kidney Disease Epidemiology Collaboration equations, and eGFR concordance was assessed. Results: Creatinine, BUN, and tCO2 correlated well with plasma samples on the cobas, and all other analytes correlated well with whole blood specimens on the GEM Premier 4000 across the tested sample ranges. The regression slope was 0.951 to 1.047, along with a correlation coefficient (r) of ≥0.982 for all analytes. The pooled within-sample precision was 0% to 2.5% for all analytes. Conclusions: ChemSTAT demonstrated a strong correlation with the comparative methods and excellent precision. The system's analytical performance and continuous quality management make it suitable for use in the ED to provide rapid reliable test results, which could minimize the time to treatment and improve ED efficiency.