Dosage of sodium and potassium in paediatric parenteral nutrition bags: Using an automated system for physicochemical control

Summary Introduction Validate an analytical method for the determination of Sodium and Potassium in parenteral nutrition bags by indirect potentiometry using correction factors; and evaluate routine control results. Material and methods An analytical method of dosage of electrolytes by Cobas Integra 400 Plus® analyzer was validated using the SFSTP guidelines. Bags of matrix admixtures were prepared for validation; electrolytes were added at different concentrations. We studied the linearity, accuracy and precision. The validated method was used to assess the conformity of electrolytes concentrations within the parenteral nutrition bags. The acceptance limit for conformity assessment was set at ± 20% of the target concentration. Results Correlation coefficients of the regression lines were higher than 0.999. The method showed good repeatability and intermediate precision (RSD  Discussion Non-conformity is increased by increasing the total volume and exceeding the theoretical capacity of the bag. The extension of the mixing time significantly increases the conformity rate. Conclusion A laboratory analyzer provides a valid and precise method for the determination of electrolytes in parenteral nutrition bags. A proper mixing is critical in order to obtain exact determination results.