“…[4] Prior studies have largely investigated clinical risk factors for new onset of dialysis-dependent renal failure occurring during the post-operative period after cardiac surgery. Clinical risk factors have included older age,[7, 13] sex,[11] race,[7] diabetes,[7–9, 13, 20, 21] peripheral vascular disease,[21, 22] baseline eGFR[9, 22] (or baseline SCr),[6–8, 13, 20, 21] poor ejection fraction,[6, 8, 9, 22] New York Heart Association class,[6–8, 13, 21, 22] congestive heart failure,[11, 20] prior acute myocardial infarction,[7, 11, 21] atrial fibrillation,[21] lung disease or chronic obstructive pulmonary disease,[6–8, 22] pre-operative intra-aortic balloon pump,[6, 8, 9, 22] emergent surgery,[8, 9] type of surgery,[6–9, 13] reoperation,[6–8, 20, 22] and low cardiac output failure or use of more than two inotropes. [11, 13] Only three studies investigated perfusion characteristics such as cardiopulmonary bypass time >120 or >180 minutes.…”