My PhD focuses on renal physiology and fluid homeostasis in elective major surgery. This is an under-investigated area where current practice is based on traumatology data from the 1950s and intensive care populations. Specific objectives include obtaining novel data on 1) current perioperative fluid therapy practice; 2) the incidence of, and risk factors for the development of acute kidney injury (AKI) in this setting; 3) the performance of two novel biomarkers of AKI; and 4) testing the hypotheses that the current perioperative urine output target (0.5ml/kg/h) is arbitrarily high, potentially harmful and that lower urine output targets are safe. These studies aim to improve the safety of fluid therapies in major abdominal surgery. As such there is enormous potential for these studies to impact practice and health outcomes worldwide. Moreover, undertaking these studies is an essential first step in understanding the process of improving health care through high quality research.