EFFECT OF MODIFIED ULTRAFILTRATION IN HIGH-RISK PATIENTS UNDERGOING OPERATIONS FOR CONGENITAL HEART-DISEASE

Background. Modified ultrafiltration (MUF) after cardiopulmonary bypas s (CPB) in children decreases body water, removes inflammatory mediato rs, improves hemodynamics, and decreases transfusion requirements. The optimal target population for MUF needs to be defined. This prospecti ve, randomized study attempted to identify the best candidates for MUF during operations for congenital heart disease. Methods. Informed con sent was obtained from 100 consecutive patients with complex congenita l heart disease undergoing operations with CPB. They were randomized i nto a control group (n = 50) of conventional ultrafiltration during by pass and an experimental group using dilutional ultrafiltration during bypass and venovenous modified ultrafiltration after bypass (MUF grou p, n = 50). Postoperative arterial oxygenation, duration of ventilator y support, transfusion requirements, hematocrit, chest tube output, an d time to chest tube removal were compared between the groups stratifi ed by age and weight, CPB technique, existence of preoperative pulmona ry hypertension, and diagnosis. Results. There were no MUF-related com plications. In patients with preoperative pulmonary hypertension, MUF significantly improved postoperative oxygenation (445 +/- 129 mm Hg ve rsus control: 307 +/- 113 mm Hg, p = 0.002), shortened ventilatory sup port (42.9 +/- 29.5 hours versus control: 162.4 +/- 131.2 hours, p = 0 .0005), decreased blood transfusion (red blood cells: 16.2 +/- 18.2 mL /kg versus control: 41.4 +/- 27.8 mL/kg, p = 0.01; coagulation factors : 5.3. +/- 6.9 mL/kg versus control: 32.3 +/- 15.5 mL/kg, p = 0.01), a nd led to earlier chest tube removal. In neonates (less than or equal to 30 days), MUF significantly reduced transfusion of coagulation fact ors (5.4 +/- 5.0 mL/kg versus control: 39.9 +/- 25.8 mL/kg, p = 0.007) , and duration of ventilatory support (59.3 +/- 36.2 hours versus 242. 1 +/- 143.1 hours, p = 0.0009). In patients with prolonged CPB (>120 m inutes), MUF significantly reduced the duration of ventilatory support (44.7 +/- 37.0 hours versus 128.7 +/- 133.4 hours, p = 0.002). No sig nificant differences were observed between MUF and control patients fo r any parameter in the presence of ventricular septal defect without p ulmonary hypertension, tetralogy of Fallot, or aortic stenosis. Conclu sions. Modified ultrafiltration after CPB is safe and decreases the ne ed for homologous blood transfusion, the duration of ventilatory suppo rt, and chest tube placement in selected patients with complex congeni tal heart disease. The optimal use of MUF includes patients with preop erative pulmonary hypertension, neonates, and patients who require pro longed CPB. (Ann Thorac Surg 1998;66:821-8) (C) 1998 by The Society of Thoracic Surgeons.