Acute kidney injury and cardiopulmonary bypass: special situation or same old problem?

Abstract

Acute kidney injury (AKI) occurring after cardiac surgery is common and extends intensive care unit and hospital length of stay, as well as increases mortality rates. Its causes are multifactorial, and are not limited to ischemia and nephrotoxin administration. One particular problem is that both anemia and blood transfusion are risk factors for AKI, and neither are generally avoidable in high-risk heart surgery. Certain etiological factors are peculiar to the cardiac surgery setting, such as routine use of cardiopulmonary bypass, and various degrees of hypothermia, which is probably nephroprotective from an ischemia point of view, but which also worsens hemolysis from the pump and thus may actually exacerbate the problem. In this paper we review the place of antifibrinolytic therapy, hemodynamic control on bypass, and the correct level of oxygen delivery in the development of AKI after open heart surgery.