Continuous haemodiafiltration during and after cardiopulmonary bypass in renal failure patients

Continuous haemodiafiltration (CHDF) is a technique enhancing the efficiency of solute clearance of haemofiltration by infusing dialysis fluid through the haemofilter. It has been reported to control water and electrolyte balance continuously without haemodynamic instability in critically ill patients with renal failure, Therefore, we used CHDF during and after cardiopulmonary bypass (CPB) in two renal failure patients, and discuss its efficacy.

The first patient undergoing aortic valve replacement had dialysis-dependent renal failure. Chronic renal failure in the second patient undergoing mitral valve replacement and coronary revascularization was controlled preoperatively with diuretics. In both cases, CHDF was performed not only during CPB but also in the post-CPB period. Serum concentrations of potassium, urea and creatinine were well-controlled in spite of large amount of blood transfused in the post-CPB period (1000 ml fresh blood and 400 ml fresh frozen plasma in the fist patient, and 1400 ml fresh blood in the second patient). There was no difficulty in haemostasis during the use of nafamostat mesilate as an anticoagulant to keep activated clotting time at about 150 sec for CHDF in the post-CPB period.

Our initial experiences of CHDF during and after CPB suggest that the technique provides excellent electrolyte, metabolite and fluid management for the cardiac patients with chronic renal failure. Combined with nafamostat mesilate for anticoagulation, CHDF was simple and safe and did not increase the risk of bleeding.