Point-of-care creatinine testing in children at risk for sudden deterioration of renal function

Background: Point-of-care testing for creatinine blood concentrations may be useful in predicting the onset of recurrent conditions threatening renal function in children at home. Our aim was to evaluate two point-of-care systems for creatinine testing vs. an automated creatinine assay. Methods: Twenty patients aged between 2 months and 17 years were randomly selected. Capillary blood specimens were taken for two point-of-care tests (Reflotron and i-STAT), and the results were compared to the routine enzymatic creatinine assay on a Hitachi 912 analyser using material collected simultaneously. Results: The mean difference in creatinine concentration between the Reflotron and the Hitachi 912 and i-STAT and Hitachi 912 test was -16 and 4 μmol/L, respectively. The slope of the Passing-Bablok method comparison was 0.95 (95% CI 0.87-1.06) and 0.96 (95% CI 0.90-1.00) for the Reflotron and i-STAT test, respectively. Conclusions: The blood creatinine concentrations measured using the Reflotron and the i-STAT device correlated well with those from the routine assay, especially in the concentration range up to 500 μmol/L. Both systems are good options for point-of-care creatinine testing in capillary blood. However, the i-STAT seems the better option for monitoring at home given its greater ease of use.