To examine kidney function, urine will be-sampled when the participant is put under general anesthesia, before surgical incision, within one hour of arrival to the ICU and 24 hours after completion of surgery. Two tubes (2 teaspoons) of blood (from an already established line) will be taken the morning of the surgery, within one hour of arrival to the ICU, 24 hours after surgery and every morning during the participants postoperative ICU stay.