ObjectiveTo summarize the clinical usage of modified ultrafiltration in pediatric cardiopulmonary bypass. MethodsWe selected 40 infants with congenital heart defects as our study subjects between January 2010 and February 2012. They were randomly divided into two groups. One group used modified ultrafiltration, while the other did not, during the operation with cardiopulmonary bypass. The different perioperative changes of pulmonary pressure and the tumor necrosis factor (TNF) and interleukin-8 (IL-8) concentration in plasma were observed in both the two groups. ResultsNo complication relative to modified ultrafiltration was found. After the operations began, TNF and IL-8 concentration in the two groups rose fast; at the end of operations and 2 hours after operation, the pulmonary pressure and TNF and IL-8 concentration in the two groups decreased, and the decrease in the modified ultrafiltration group was faster. ConclusionThe use of modified ultrafiltration during operations with cardiopulmonary bypass can reduce residual water within the body in a short period and decrease the concentration of inflammatory factors, which is helpful for postoperative recovery of the cardiac and lung functions.