Optimizing Perioperative Renal Replacement Therapy for Patients Undergoing Cardiac Surgical Procedures Requiring Cardiopulmonary Bypass

Coronary artery disease is highly prevalent in patients with end-stage renal disease (ESRD), and cardiovascular complications remain the most common cause of death in this patient population. Accordingly, many cardiac surgical procedures requiring cardiopulmonary bypass support are performed on these patients each year, with morbidity and mortality rates far exceeding patients without ESRD. Anuric patients lack the normal renal homeostatic functions which typically allow for physiologic protection from challenges during the operation, such as volume overload, hyperkalemia, and acidemia. Careful preoperative planning and coordination to provide pre-, intra-, and postoperative renal replacement therapies for such patients are imperative. Many different strategies have been reported in the literature. Zero-balance ultrafiltration is a newer strategy which utilizes convective ultrafiltration much like pre-filter continuous renal replacement therapy and utilizes pre-existing connections on the cardiopulmonary bypass pump performed by the perfusion team. This allows for control of potassium concentration throughout the operation with existing personnel and minimal additional equipment. Here, we describe the unique challenges caring for patients receiving renal replacement therapy undergoing cardiac surgical procedures requiring cardiopulmonary bypass.