Abstract Background: Cardiopulmonary bypass (CPB) causes systemic oxidative stress response and endothelial damage in systemic organs. We investigated the effects of positive end-expiratory pressure (PEEP) and mechanical ventilation (MV) applications on oxidative stress in CPB. Methods: Seventy-one patients were recruited and 60 completed the study. Randomized groups: MV off (Group 1); MV on, tidal volume (TV) at 3-4 mL.kg-1 (Group 2); MV on, TV at 3-4 mL.kg-1, PEEP at 5 cmH2O (Group 3), n = 20 in each group. As oxidative stress markers, we used glutathione peroxidase (GPx), total antioxidant status (TAS), total oxidant status (TOS), total and native thiol (TT, NT), malondialdehyde (MDA), and catalase. We also investigated the correlation between oxidative stress and postoperative intubation time. Results: The postoperative GPx levels in Group 2 were higher than Group 3 (p = 0.017). In groups 2 and 3, TAS levels were higher postoperatively than intraoperatively (p = 0.001, p = 0.019, respectively). In Group 2, the TT levels were higher postoperatively than preoperatively and intraoperatively (p = 0.008). In Group 3, the postoperative MDA levels were higher than preoperatively (p = 0.001) and were higher than both postoperative levels of Group 1 and 2 (p = 0.043, p = 0.003). As the preoperative TAS (Group 2) decreased and the postoperative NT (Group 2) and catalase (Group 3) increased, the postoperative intubation time lengthened. Conclusion: MV (3-4 mL.kg-1) alone seems to be the most advantageous strategy. Prolonged postoperative intubation time was associated with both increased NT and catalase levels.

Abstract Objective: Our goal was to compare the operative and postoperative effects of del Nido cardioplegia (DN group) and blood cardioplegia (BC group) performed in cardiac surgery. Methods: A total of 83 patients were included, separated into DN group and BC group. The operative and postoperative effects of the two groups were compared for the first 24 hours until extubation. The operative and postoperative complete blood count (CBC), biochemical values and clinical parameters were compared. Results: The first control activated clotting time (ACT) levels in DN group patients were lower (P=0.003) during the operation. The amount of cardioplegia in DN group were lower than that in BC group (P=0.001). The pump outflow and postoperative lactate level of DN group were lower than those of BC group (P=0.005, P=0.018, respectively), as well as the amounts of NaHCO3 (P=0.006) and KCl (P=0.001) used during the operation. The same occurred with the first monocytes (Mo) and mean corpuscular volume (MCV) levels in the postoperative intensive care unit (P=0.006, P=0.002). However, the first glucose level and the eosinophil (Eo) level were higher in DN group (P=0.011, P=0.047, respectively). Conclusion: In the operative evaluation, the amount of cardioplegia, the first ACT levels, the pump outflow lactate level and the amounts of NaHCO3 and KCl in DN group were lower. In postoperative evaluation, measured level of lactate, Mo and MCV in DN group were all lower; their glucose and Eo levels were higher.