Acute renal failure after cardiothoracic surgery: a review of three years experience

2,683 cardiothoracic operations were carried out over a 3-year period. Patients requiring haemofiltration after surgery had a much greater mortality than those not haemofiltered. Of the 1,177 cardiothoracic intensive care unit (ICU) patients, 91 required haemofiltration for acute renal failure (ARF; 7.7%). Of the 1,506 cardiothoracic high-dependency unit patients 13 were transferred to the renal unit for dialysis (0.86%). Mortality for cardiothoracic patients overall was 14.4% and for those who required haemofiltration 58.7%. 74 of these haemofiltered patients had normal renal function preoperatively; mortality 61%. 15 patients had pre-existing renal impairment; mortality 53.3%. 15 patients were on dialysis prior to surgery; mortality 60%. Age was not a predictor of requirement for renal replacement therapy or of mortality. Operation type was a risk factor for ARF: of patients having a coronary artery bypass graft (CABG) 2.4% were filtered (mortality 37.8%), of patients having valve replacements 14.2% were haemofiltered (mortality 60.9%), and of the patients having redo-CABGs or redo-valve replacements 12.3% required haemofiltration (mortality 100%).