Lidocaine adsorption to ethylene-vinyl acetate infusion bags decreases its availability in del Nido cardioplegia solution

Abstract

Del Nido cardioplegia solution (dNCS) is frequently used in cardiac surgery. As dNCS is often in-house prepared by hospital pharmacies, an appropriate preparation and storage conditions need to be found and validated. In this study, an 8-week (i.e., 56 days) stability test was performed to monitor the effect of several variables on the stability of dNCS manufactured internally at a hospital pharmacy. Six dNCS variants were prepared that differed in the material of container used, i.e., ethylene-vinyl acetate (EVA) infusion bags or glass infusion bottles, magnesium ions source, and the presence or absence of sodium bicarbonate. Each variant was evaluated for its stability while maintaining at 4 °C, 22 °C, or 50 °C. The concentrations of constituents were monitored using HPLC and capillary electrophoresis. It was found that dNCS is stable at 4 °C for 8 weeks and that the replacement of magnesium chloride with magnesium sulfate and/or the absence of sodium bicarbonate has no effect on the stability. On the other hand, if dNCS is not refrigerated or maintained at elevated temperature, the lidocaine concentration in the solution stored in EVA bags can be significantly altered by adsorption of lidocaine to infusion bag material (within 25 days, lidocaine concentration decreases as low as to one half of the original value). Therefore, the dNCS stored in EVA bags should be maintained at 4 °C to avoid alternation of its pharmacological effect, because when the solution stored in EVA bag is maintained at elevated temperature, the concentration of lidocaine can be significantly changed. Such change influences the pharmacological effect of the solution leads to serious complications and even endangers the health or life of patients.

Graphic abstract