Accuracy and Reliability of Continuous Glucose Monitoring in the Intensive Care Unit: A Head-to-Head Comparison of Two Subcutaneous Glucose Sensors in Cardiac Surgery Patients

Hyperglycemia, hypoglycemia, and glucose variability are common during intensive care unit (ICU) stay and are associated with increased mortality (1–3). Continuous glucose monitoring (CGM) is a promising tool to assist glucose control, but the accuracy and reliability of these devices in critically ill patients is uncertain (4,5). Therefore, we studied two different CGM devices postoperatively in cardiac surgery patients in an investigator-initiated trial.We placed two CGM devices (Guardian RT, Medtronic Minimed; FreeStyle Navigator, Abbott Diabetes Care) subcutaneously in the abdominal wall before surgery in 60 patients. This is the first time the Navigator has been studied in an ICU setting. Both devices were calibrated simultaneously upon arrival at the ICU after surgery. Further calibrations were performed according to manufacturers’ instructions. An arterial blood glucose value was measured with an AccuChek device (Performa II, …