Evaluate the Performance of the Dexcom G7 Continuous Glucose Monitoring (CGM) System in Critically Ill Patients Undergoing Major Abdominal Surgery and Solid Organ Transplantation Which Require Blood Glucose Monitoring for Intensive Insulin Therapy.

Main objective: The goal is to to determine the accuracy of Dexcom G7 Continuous glucose monitor system in critically ill patients, undergoing major abdominal surgery and solid organ transplantation, in the intensive care unit. On admission to the intensive care unit or at the end of surgery, two Dexcom G7 sensors are placed in the infraclavicular position. Sensor number 1 will be blinded and will only be active when paired with the receiver, without the ability to monitor glucose levels. Sensor number 2 is used for continuous glucose monitoring and can be used to adjust the insulin dose. Patients will wear the continuous glucose monitoring sensor for a maximum of 10 days, including the time spent in the intensive care unit and the immediate care unit. The study will not interfere with any usual care clinical workflows. Calibration is only performed on an unblinded sensor. The refe