 We plan to study to 200 patients 50 years of age scheduled for procedures requiring cardiopulmonary bypass whether for coronary revascularization or valvular surgery. After informed consent is obtained each patients preoperative lab values consisting of serum glucose, urine glucose, creatinine and BUN will be noted. Each patients pre-induction hemodynamics will also be noted. During bypass, serum and urine glucose will be measured every 20 minutes in addition to collecting information on temperature of cardioplegic solution, lowest patient temperature, time of bypass, and use of diuretics, or vasoactive drugs. Additional sampling of serum creatinine and glucose and vital signs will take place upon arrival in the cardiac intensive care unit after surgery and throughout hospitalization as is standard of care in cardiac surgery at this institution. No extra samples will be taken but the standard measurements will be observed. The clinical outcome of interest is a new onset of renal dysfunction defined as a post-operative serum creatinine change of 0.5 mgdl or greater after surgery. 