Mending a broken heart but breaking the kidney

The incidence of acute kidney injury (AKI) is a frequent and serious complication of cardiac surgery. In 2013, 95% of cardiac surgical procedures performed in Australia and New Zealand used cardiopulmonary bypass (CPB). AKI following CPB is well known, yet the perioperative factors contributing to its development are incompletely understood. AKI following CPB has significant implications on both short-term and long-term outcomes. The techniques for conducting CPB have evolved, moving towards evidence-based practice; however, there is still no generally accepted definition of optimal perfusion and its conduct. This review examines the current incidence of AKI following cardiac surgery and the short-term and longer-term effects of AKI on morbidity and mortality. The purpose of this review is to discuss the perioperative risk factors related to CPB and their contribution to the development of AKI. This review will also discuss outcomes in regard to off-pump cardiac surgery, the role of remote ischaemic preconditioning on AKI and outcomes in patients with chronic renal failure undergoing cardiac surgery.