The Effect of Normovolemic Modified Ultrafiltration on Inflammatory Mediators, Endotoxins, Terminal Complement Complexes and Clinical Outcome in High-Risk Cardiac Surgery Patients

OBJECTIVE:

The clinical benefit of normovolemic modified ultrafiltration (N-MUF) after cardiac surgery is still debated. As we have shown in a previous publication, there is a significant improvement in platelet function, so we were interested in whether ultrafiltration can reduce plasma levels of endotoxins, terminal complement complexes and cytokines after cardiopulmonary bypass (CPB) in adults with increased risk profiles.

METHODS:

In this single-center, prospective, randomized trial, fifty high-risk patients (mean logistic EuroSCORE II: 17.5%) who underwent cardiac surgery were randomized. After CPB, Group 1 (n = 25) served as the control and in, Group 2 (n= 25), an N-MUF of 3000 ml was performed, using a BC140plus filter after weaning from CPB. Blood samples were taken after the induction of anesthesia, before CPB, before CPB weaning, 30 minutes after CPB and at 6, 24 and 48 hours postoperatively. Primary outcomes were plasma levels of lipopolysaccharide-binding protein (LBP), terminal complement complex (C5b9) and cytokines (IL-6, IL-10, IL-1beta, TNF-α). Secondary outcomes focused on differences in the clinical outcome.

RESULTS:

A significant reduction in LBP concentration (preoperatively: 23.8±8.4 pg/ml, postoperatively: 14.2±12.9 pg/ml) and C5b9 (preoperatively: 4.18±2.6 pg/ml, postoperatively: 3.05±2.39 pg/ml) were detected 6 hours after N-MUF. In the N-MUF group, significantly lower concentrations of lactate could be detected in the early postoperative period. Furthermore, postoperative chest tube blood loss was significantly lower in the N-MUFgroup at 24 and 48 hours.

CONCLUSIONS:

N-MUF leads to a significant reduction of lipopolysaccharide-binding protein and terminal complement complex and was associated with reduced blood loss and postoperative lactate concentrations shortly after surgery.