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.
Key Findings
Results
Mean fluid balance was significantly more negative in the SBUF-SMUF group compared to a significantly positive balance in the CUF group.
Mean fluid balance was +192.1 ± 178.8 mL in the CUF group versus -105.0 ± 78.9 mL in the SBUF-SMUF group (p < 0.001).
The study enrolled 80 pediatric patients with congenital heart disease, randomized equally (n = 40 per group).
This was a prospective, randomized, outcome-assessor-blinded clinical trial.
The negative fluid balance in the SBUF-SMUF group indicates superior fluid removal during cardiopulmonary bypass.
Results
The SBUF-SMUF group required significantly less intraoperative packed red blood cell (PRBC) transfusion than the CUF group.
Intraoperative PRBC use was 141.7 ± 70.2 mL in the SBUF-SMUF group versus 261.0 ± 68.8 mL in the CUF group (p < 0.001).
This represents an approximately 46% reduction in intraoperative PRBC transfusion volume in the SBUF-SMUF group.
Statistical analysis was conducted using independent t-tests for continuous variables.
Results
Postoperative fresh frozen plasma (FFP) transfusion was significantly less frequent in the SBUF-SMUF group compared to the CUF group.
Postoperative FFP transfusion occurred in 2% of SBUF-SMUF patients versus 10% of CUF patients (p = 0.020).
Chi-square or Fisher's exact tests were used for categorical variables including transfusion rates.
Reduced FFP requirements suggest improved coagulation factor conservation or reduced hemodilution with SBUF-SMUF.
Results
Post-bypass hematocrit levels were significantly higher in the SBUF-SMUF group than in the CUF group.
Mean post-bypass hematocrit was 31.2% in the SBUF-SMUF group versus 27.3% in the CUF group (p = 0.001).
Higher hematocrit levels following bypass reflect improved hemoconcentration with the SBUF-SMUF technique.
Improved hematocrit may directly contribute to the reduced need for PRBC transfusion observed in the SBUF-SMUF group.
Results
Extubation occurred significantly earlier in the SBUF-SMUF group compared to the CUF group.
Mean time to extubation was 1.05 ± 1.03 days in the SBUF-SMUF group versus 2.27 ± 2.37 days in the CUF group (p = 0.006).
Earlier extubation in the SBUF-SMUF group may reflect better fluid management and reduced pulmonary edema.
This finding suggests a potential benefit for postoperative recovery and reduced mechanical ventilation duration.
Results
No significant differences in potassium levels or incidence of acute kidney injury were observed between the two groups.
The absence of significant differences in potassium levels indicates that SBUF-SMUF did not increase the risk of electrolyte imbalance compared to CUF.
No additional risk of oliguria was observed in the SBUF-SMUF group compared to CUF.
Acute kidney injury incidence was comparable between groups, supporting the safety profile of SBUF-SMUF.
These safety findings were noted across both intraoperative and postoperative assessment periods.
Methods
Demographic and preoperative variables were comparable between the CUF and SBUF-SMUF groups at baseline.
Baseline comparability was confirmed across 80 pediatric patients with congenital heart disease (n = 40 per group).
Comparable baseline characteristics support the validity of between-group comparisons in outcome measures.
The trial design was prospective and randomized with outcome-assessor blinding to reduce bias.
Statistical significance was defined as a two-tailed p-value of less than 0.05.
What This Means
This research suggests that a newer method of fluid management during heart surgery in children — called SBUF-SMUF (subzero balanced ultrafiltration combined with simple modified ultrafiltration) — works better than the conventional approach (CUF) in several important ways. In a clinical trial of 80 children with congenital heart disease, those who received SBUF-SMUF ended up with a net fluid loss during surgery, while children in the conventional group gained fluid. The SBUF-SMUF group also needed about half as much blood transfusion during surgery, had higher red blood cell concentrations after surgery, and were taken off the breathing machine about a day earlier on average.
Importantly, the newer technique did not appear to cause any additional harm. There were no differences between groups in kidney injury rates, electrolyte imbalances (such as abnormal potassium levels), or low urine output. This suggests that the more aggressive fluid removal achieved by SBUF-SMUF can be done safely in pediatric patients undergoing open-heart surgery with cardiopulmonary bypass.
This research suggests that SBUF-SMUF could potentially become a standard approach for managing fluids during pediatric heart surgery, given its apparent safety and its benefits in reducing the need for blood products, improving blood concentration, and supporting faster recovery from mechanical ventilation. The authors note that the technique's simplicity and reproducibility further support its potential for broader clinical adoption.
Shadmehr M, Ali B, Abdollahzadeh R, Zarrabi K, Gerami H, Butt S. (2026). SBUF-SMUF: On the path to the optimum hemofiltration technique in pediatric cardiopulmonary bypass: A randomized clinical trial.. The journal of extra-corporeal technology. https://doi.org/10.1051/ject/2026020