Procalcitonin plasma levels before operation and 24 hours after cardiopulmonary bypass. Procalcitonin (PCT) plasma levels in the treated and control groups, before operation (t1) and 24 hours after cardiopulmonary bypass (t5). Significant elevation was found in both groups (*Friedman tests). After the operation, procalcitonin was lower in group A. The between-group difference was significant (+ Kruskal–Wallis test).