Continuous Glucose Monitoring in Intensive Care Unit

This will be a non-commercial, investigator-driven, active comparator-controlled, randomized, open-label and non-inferiority clinical study to be performed at the Institute for Clinical and Experimental Medicine in Prague. Patients that are being prepared for one of the surgical procedures mentioned below will be asked to participate: 1. pancreas surgery - total or partial pancreas resection 2. orthotopic liver transplantation 3. simultaneous pancreas and kidney transplantation 4. patients with diabetes mellitus undergoing major surgery After obtaining the informed consent, they will be randomized into one of two treatment groups: 1. Study arm with continuous glucose monitor added to standard treatment, where the values obtained by CGM will aid in adjusting the insulin treatment. 2. Control arm with blinded continuous glucose monitor that will be treated according to the standard of care, where the CGM data will be collected in a blind fashion and evaluated after completion of the follow-up. Each surgical group will be randomized and evaluated separately and independently. Continuous glucose monitoring will be initiated after completing the surgical procedure in order to avoid interferences during the procedure. Insulin therapy will be adjusted according to the standard in-house ICU protocol for insulin dose adjustment.