Systemic Inflammation – Antioxidative Status during Fontan Operation

Background: Cardiopulmonary bypass (CPB) in pediatric heart surgery plays an important role in the activation of oxidative stress and is therefore assumed to be a contributing cause of systemic inflammation syndrome. We investigated the role of the antioxidative system during Fontan operation (FO), which has recently been performed also without CPB support in our unit.

Methods: In 20 consecutive patients who underwent FO in 2011 to 2012 total antioxidative status (TAS) as marker of antioxidative capacity in EDTA plasma sample was obtained before, during, and after surgical procedure. We compared TAS between one group operated on with CPB support (On-Pump; n= 9) and one without (Off-Pump; n= 11). Preoperative and anesthesiological management was equal in all patients.

Results: Before operation and implementation of CPB there were no significant differences in TAS between the two groups (p= 0.88). The On-Pump group showed significantly higher TAS after initiation of CPB (p= 0.016) and at the end of the operation (p= 0.02). Although TAS levels in the On-Pump group were elevated during surgical procedure, they initially decreased in the Off-Pump group, but were elevated again 4 hours postoperatively. Four hours postoperatively (p= 0.056) and 24 hours postoperatively (p= 0.30) no significant differences between the groups were detectable. Higher levels of TAS 24 hours postoperatively correlate with longer duration of ventilatory support (p= 0.034) and a prolonged need for catecholamines (> 72 hours; p= 0.015).

Conclusions: Usage of CPB seems to induce activation of the oxidative system. Activation of antioxidative system may negatively affect the postoperative outcome, including prolonged need for mechanical ventilation, and contribute to low cardiac output.