Acute renal failure after cardiovascular surgery. Current concepts in pathophysiology, prevention and treatment

Acute renal failure (ARF) is a serious complication of cardiovascular surgery and has a high mortality rate, especially with oliguria. It is usually caused by ischaemic injury of the kidney, resulting from inadequate perfusion. Certain risk factors which might lead to the development of ARF following open heart operations have been identified: age >70 years; elevated pre-operative serum creatinine; low blood pressure during cardiopulmonary bypass; rate of haemolysis; a postoperative critical circulation. It is necessary to establish the diagnosis as soon as possible in order to institute corrective measures to prevent oliguric ARF. Once renal failure is established close control of hydration, solutes and potentially toxic metabolites is necessary. Early renal replacement therapy with proper nutritional support appears to improve survival.