A finite element model for insulin adsorption in ICU infusion sets

Clinical Recommendations for Managing the Impact of Insulin Adsorptive Loss in Hospital and Diabetes Care

BACKGROUND

Adsorption of insulin to infusion sets impacts patient therapeutic outcomes and, unaccounted for, may exacerbate persistent hyperglycemia or result in therapy-induced hypoglycemia. This article aims to provide recommendations for clinicians involved in intensive care and/or outpatient pump therapy contexts.

METHODS

A dynamic adsorption model is used to evaluate time-varying insulin concentration in the infusion set outflow. Hourly and daily percentage insulin loss to adsorption is examined for neonatal, pediatric, and adult intensive care patients, as well as outpatient children and adults weighing 30, 50, and 80 kg. A short review of preconditioning methods is included.

RESULTS

Insulin adsorption in outpatient pump therapy is most pronounced in the first hour, where as much as 80% of the intended insulin dose may be lost to adsorption. Subsequently, insulin adsorptive loss is typically negligible. Overall, extra care should be taken in the first 1-6 h of a new infusion set, particularly in children or teenagers. Typically, insulin adsorption in the adult intensive care unit is negligible unless infused at low flow rates (<2 mL/h). Insulin adsorption is significant in pediatric and neonatal intensive care, resulting in delivery concentrations as low as 5%-50% of that intended. Thus, it is recommended that preconditioning of insulin delivery lines be carried out prior to infusion initiation in this context. However, no preconditioning method completely removes adsorption, and care should still be taken in the first 1-6 h of insulin dosing.

CONCLUSIONS

Recommendations made in this article are dependent on the insulin concentration and flow rate used in each clinical context.