SBUF-SMUF: On the path to the optimum hemofiltration technique in pediatric cardiopulmonary bypass: A randomized clinical trial.

BACKGROUND: Hemofiltration during pediatric cardiopulmonary bypass (CPB) is essential to mitigate hemodilution, inflammatory responses, and postoperative complications. Conventional ultrafiltration (CUF) is widely practiced, but novel methods such as subzero balanced ultrafiltration combined with simple modified ultrafiltration (SBUF-SMUF) may offer superior outcomes. OBJECTIVE: To compare the clinical efficacy and safety of CUF versus SBUF-SMUF in pediatric patients undergoing open-heart surgery. METHODS: In this prospective randomized, outcome-assessor-blinded clinical trial, 80 pediatric patients with congenital heart disease were allocated to either CUF (n = 40) or SBUF-SMUF (n = 40) during CPB. Baseline demographics, intraoperative characteristics, fluid balance, blood product utilization, and postoperative outcomes were assessed. Statistical analysis was conducted using independent t-tests, Chi-square tests, and Fisher's exact tests. Statistical significance was defined as a two-tailed p-Value of less than 0.05. RESULTS: Demographic and preoperative variables were comparable between groups. Mean fluid balance was significantly positive in the CUF group (+192.1 ± 178.8 mL) but negative in the SBUF-SMUF group (-105.0 ± 78.9 mL, p < 0.001). The SBUF-SMUF group required significantly less intraoperative PRBC (141.7 ± 70.2 vs. 261.0 ± 68.8 mL, p < 0.001) and postoperative FFP transfusion (2% vs. 10%, p = 0.020). Post-bypass hematocrit levels were higher (31.2% vs. 27.3%, p = 0.001) and extubation occurred earlier in the SBUF-SMUF group (1.05 ± 1.03 vs. 2.27 ± 2.37 days, p = 0.006). No significant differences were observed in potassium levels or incidence of acute kidney injury. CONCLUSION: The SBUF-SMUF technique is safe, effective, and superior to CUF in optimizing fluid balance, reducing blood product utilization, and facilitating earlier extubation in pediatric cardiac surgery. No additional risk of oliguria or electrolyte imbalance was observed compared to CUF. Its simplicity and reproducibility support its consideration as a standard approach in pediatric CPB.