Haemodialysis during cardiopulmonary bypass using a haemofilter.

The decision to employ haemofiltration and/or haemodialysis is based on various criteria depending on institutional protocol. Cardiac surgical patients, especially those with renal failure, often require fluid and electrolyte intervention. In the past haemodialysis patients were closely monitored and often delayed for surgery depending on their electrolyte status. Operative technique was changed to accommodate the impending sequelae of cardioplegic solutions, blood transfusions and fluid administration. Although haemofiltration has been used successfully in the management of hypervolaemia and anaemia due to haemodilution, the rate of uraemic toxins and solute removal may not be adequate. The use of haemodialysis helps in the treatment of these difficult and often unpredictable cases. The type of dialysate and method of administration has simplied the technique of haemodialysis, during CPB, allowing effective solute and toxin removal while being able to control the amount of fluid removed.