Accuracy of Flash Glucose Monitoring in Critically Ill Patients Receiving Intravenous Insulin

Abstract

Objective: To compare the Free Style Libre (FSL) 2 14day Flash Glucose Monitoring (FGM) and Point-Of-Care Capillary (POC) Blood Glucose (BG) testing among critically ill patients who receive insulin infusion. Methods:We conducted an open-label, prospective study and enrolled stepdown or critical care unit patients on intravenous insulin. Paired POC and GCM values were obtained to calculate the Mean Absolute Relative Difference (MARD). Accuracy was further evaluated with error grid analysis between matched glucose pairs. Results: Using POC BG as the reference, the overall MARD was 8.65%. For POC BG of 70-180, MARD was 10.02%, whereas for POC BG of > 180 mg/dL, MARD was 6.74%. Error grid analysis showed 99.9% of glucose pairs within zones A and B. Conclusion:FSL2 exhibits satisfactory accuracy in critically ill patients receiving insulin infusion, suggesting the future use of FGM in guiding insulin dosing for this subgroup of patients.