Adsorption of human and porcine insulins to intravenous administration sets.

A comparison between human and porcine insulins with regard to their adsorption to administration sets was performed. A 125I-mono(A14)-iodinated insulin was used to follow the adsorption phenomenon over time and the adsorption was quantified with radioimmunoassays of unlabelled insulin. The obtained data were similar for both methods. No relevant difference in adsorption was found between human and porcine insulin. Both insulins showed a significantly more pronounced initial drop in delivered insulin when polyethylene tubing was used. After 3 h a steady state was reached, resulting in the administration of a more predictable dose. Particularly in the initial phase an important reduction in the amount of both insulins actually delivered to the patient was observed when compared to the expected amount as calculated from the concentration present in the container and the infusion rate. Therefore, the mainstay in treatment of a patient with ketoacidosis remains frequent serum glucose measurement and making appropriate infusion rate adjustments on that basis.