Pulmonary function after modified venovenous ultrafiltration in infants: A prospective, randomized trial

Objective: We sought to examine the effects of modified venovenous ultrafiltration after cardiopulmonary bypass on pulmonary compliance in infants. Methods: We prospectively enrolled 38 infants undergoing their first operation for congenital heart disease. Infants were randomized to receive 20 minutes of modified ultrafiltration after bypass or control, Static and dynamic compliance was measured after induction of anesthesia, before and immediately after filtration in the operating theater, 1 hour after return to the pediatric intensive care unit, and 24 hours after the operation. Length of time on the ventilator, inotropic requirements, and length of stay in the intensive care unit were recorded. Results: Modified ultrafiltration produced a significant immediate improvement in dynamic (pre-ultrafiltration 2.5 +/- 1.9 mL/cm H2O to post-ultrafiltration 2.9 +/- 2.7 mL/cm H2O, P =.03) and static (pre-ultrafiltration 2.1 +/- 0.9 mL/cm H2O to post-ultrafiltration 2.9 +/- 2.1 mL/cm H2O, P =.04) compliance. However, there was no significant difference in the change in dynamic (P =.3) or static (P =.7) compliance in the ultrafiltration and control groups when compared before the operation, after the operation, and at 24 hours. There was no significant difference in the time to extubation between patients and control subjects (140 +/- 91 hours vs 90 +/- 58 hours) or the length of intensive care unit stay (10.0 +/- 9.1 days vs 7.4 +/- 5.7 days). Conclusions: Modified ultrafiltration produces an improvement in pulmonary compliance after bypass in infants. However, these improvements are not sustained past the immediate post-ultrafiltration period and do not lead to a decreased length of intubation or intensive care unit stay.