The Novel Use of a Low Prime Modified Ultrafiltration Apparatus in a 13-kg Jehovah's Witness Patient: A Case Report

Modified ultrafiltration (MUF) is used in neonates and infants to reduce volume overload and increase oxygen-carrying capacity post cardiopulmonary bypass (CPB). In addition, it decreases edema, attenuates complementation activation and immunogenic response to CPB. Hemodilution in the pediatric patient has always been a challenge, countered in part by miniaturization of CPB circuits. We describe a case in which we maintained an acceptable hematocrit level greater than 24%, considered the nadir below which the adverse effects of hemodilution can become evident. We performed this by the novel use of an intravenous warming device (enFlow, Vyaire Medical, Mettawa, IL) to reduce the prime volume of our MUF circuit by more than 50%. We present the case and discuss the advantages and disadvantages of using a low-prime MUF circuit. We were able to conduct "bloodless" CPB, with the use of acute normovolemic hemodilution, miniaturization of the CPB and MUF circuits.