To determine if High MAP or Low MAP will provide the most optimal renal function. The primary endpoints will be 96h UOP and change in creatinine levels. UOP will be calculated as cc/24 hours. The investigators will compare the change in urinary output of day 1 versus day 4. Creatinine will be measured daily and the change from initiation to completion of the study will be recorded. The mean values of these will be compared.