Study of the effectiveness of nitric oxide use during and after heart valve surgery with cardiopulmonary bypass

Aim. To assess the effect of nitric oxide administered into the extracorporeal circuit and during the three-day postoperative period on oxidative stress parameters and the state of red blood cells during operations with cardiopulmonary bypass (CPB). Material and Methods. The study included 106 patients who underwent heart valve surgeries and combined interventions under CPB. Two groups of patients were created: control (53 patients); study (53 patients). Nitric oxide (40 ppm) was supplied to the oxygenator of the CPB machine and by inhalation for three days after surgery. At the stages and after the surgery, the concentration of diene (DC) and triene (TC) conjugates, Schiff bases (SB); erythrocyte catalase activity (CA) was studied; aggregation and electrophoretic mobility of erythrocytes were measured. Clinical outcomes of surgeries were studied. Results. In patients of the control group, statistically significant increase in the content of DC (by 1.2 times) and SB (by 2.0 times) was registered by the end of the surgery compared to the initial values. SB content did not return to the preoperative level even by the end of the third day after the operation. A sharp decrease in CA activity by the end of the operation (by 24.1%) and its further decrease during three postoperative days were marked. A statistically significant increase in erythrocyte aggregation was established, starting from 60 min of CB (by 18.0% higher than the initial one), reaching a maximum by the end of the operation (by 20.4% higher than the initial one) and remaining above the initial level throughout the postoperative period. The use of nitric oxide during and after the surgery made it possible to statistically significantly decrease the level of DC, TC, SB; increase the activity of erythrocyte catalase; reduce erythrocyte aggregation and increase their electrophoretic mobility both during CBP and in the postoperative period. Conclusion. Cardiopulmonary bypass stimulates the development of lipid peroxidation (LPO) processes and erythrocyte damage, which occur during surgery and continue in the immediate postoperative period. Nitric oxide, used both during cardiopulmonary bypass and during the three-day postoperative period, effectively prevents the activation of LPO processes, has an antioxidant effect, reduces erythrocyte aggregation and increases their electrophoretic mobility. The positive effect of nitric oxide is noted not only during cardiopulmonary bypass, but also during the postoperative period, which improves the clinical outcomes of heart surgery.