SAT-639 Is the Freestyle Libre Flash Glucose Monitor Accurate in the Critically Ill?

Abstract

The FreeStyle Libre flash glucose monitor (FGM) has made the use of continuous glucose monitors more accessible to the typical diabetes patient in an outpatient setting given the significantly lower cost and ease of use of FGM as compared to other systems. However, FGM is not labeled for use in a critically ill population. The critical care department at our institution queried the endocrine department about studying the use of FGM in critically ill patients. The interest of the critical care department was due to the potential of decrease in patient discomfort and decrease in time and effort of nursing and support staff related to the performance of fingerstick capillary glucoses if FGM was an adequate replacement measure. As of yet, there has been only minimal study of flash glucose monitoring in critically ill patients. One Australian study evaluated 8 patients in an ICU setting and determined that as compared with arterial blood glucose monitoring, flash glucose monitoring provided acceptable numerical and clinical accuracy.1 A Swedish study evaluated a total of 26 patients undergoing cardiac surgery and compared the use of FGM to use of a microdialysis intravascular system and concluded that the microdialysis system was more accurate, though in this study, only 25% of patients had diabetes. 2 To further investigate use of FGM in a critically ill population, we plan to undertake a single center, prospective, single arm study enrolling at least 20 and up to 40 patients. Inclusion criteria include a known diagnosis of type 1 or type 2 diabetes, age of 18 or older, and admission to the medical intensive care unit (MICU) with expected MICU stay of at least 48 hours. Participating subjects will have a sensor applied by a study investigator. After confirmation that the sensor is operational, the investigator will place opaque tape over the monitor to blind the monitor data. Nurses or medical assistants will conduct the standard of care fingerstick glucose monitoring per hospital protocol but will also have been notified of request to also pass FGM reader over the sensor at time of fingerstick glucose data collection. The primary objectives are to determine numerical accuracy in a critical care setting using the mean absolute relative difference and to determine clinical accuracy in a critical care setting using the surveillance error grid and the clarke error grid analyses. Preliminary data should be available by March, 2020. 1. Ancona P, Eastwood GM, Lucchetta L, Ekinci EI, Bellomo R, Martensson J. The performance of flash glucose monitoring in critically ill patients with diabetes. Crit Care Resusc 2017; 19: 167-174, June 2017. 2. Schierenbeck F, Franco-Cereceda A, Liska J. Accuracy of 2 Different Continuous Glucose Monitoring Systems in Patients Undergoing Cardiac Surgery: Intravascular Microdialysis Versus Subcutaneous Tissue Monitoring. Journal of Diabetes Science and Technology 2017, Vol. 11(1) 108–116