Combined Administration of Nitric Oxide and Hydrogen into Extracorporeal Circuit of Cardiopulmonary Bypass as a Method of Organ Protection during Cardiac Surgery

The aim is to study the effect of combined introduction of nitric oxide and hydrogen into the extracorporeal circuit of cardiopulmonary bypass (CPB) for antioxidant activity and organ damage during cardiac surgery.Materials and Methods. The study included 91 patients who underwent heart surgery under CPB. The patients were randomized into 3 groups: group 1 comprised 30 patients (control); group 2 consisted of 33 patients with an isolated supply of nitric oxide (40 ppm) to the extracorporeal circuit; group 3 included 28 patients with a combined supply of nitric oxide (40 ppm) and hydrogen (1.2 ppm) into the extracorporeal circuit. The intensity of lipid peroxidation processes was studied by the content of diene conjugates (DC), triene conjugates (TC), Schiff bases (SB) in blood plasma; erythrocyte aggregation was also examined. The studies were carried out at the following stages: stage 1 (initial) - after induction of anesthesia; stage 2 - before CPB; stage 3 - 5 min after CPB initiation; stage 4 - at the 30th minute of CPB; stage 5 - at the 60th minute of CPB; stage 6 - at the 90th minute of CPB; stage 7 - at CPB termination; stage 8 - at the end of the operation.Results. The content of DC increased statistically significantly at the 90th minute of CPB to 1.093 +/- 0.573 rel. units (M +/- SD) in patients of group 1; to 0.322 +/- 0.047 rel. units in group 2; to 0.287 +/- 0.003 rel. units in group 3, while the DC content was statistically significantly lower in patients of groups 2 and 3 compared to group 1. A statistically significant increase in the content of TC compared to the initial value was observed at the 90th minute of CPB in group 1 (up to 0.334 +/- 0.114 rel. units), while the content of TC was statistically significantly lower in patients of groups 2 and 3. A statistically significant growth in the content of SB occurred at the 90th minute of CPB in patients of group 1 up to 33.324 +/- 15.640 rel. units. This indicator was statistically significantly lower in groups 2 and 3 relative to the patients of group 1. The dynamics of erythrocyte aggregation in patients of group 1 showed statistically significant growth of this indicator from the start of CPB to the end of the operation (from 44.8 +/- 1.4 to 73.1 +/- 2.2%). The statistically significant difference from the indicator at the beginning of the operation started at the 30th minute of CPB and lasted until the end of the operation. In patients of group 2, it decreased statistically significantly during CPB (from 56.5 +/- 2.3% before the CPB initiation to 47.4 +/- 1.2% at the CPB termination); in patients of group 3, it was decreasing from the 60th minute of CPB to the end of the operation and was statistically significantly lower than in patients of both groups 1 and 2. No postoperative complications were noted (acute heart failure, acute respiratory failure, multiple organ failure) in patients of groups 2 and 3. A statistically significant decrease in both the duration of mechanical ventilation and stay in the intensive care unit was registered in group 3 compared to group 2.Conclusion. The combined use of gaseous nitric oxide and hydrogen during CPB allowed a statistically significant decrease in the level of activation of lipid peroxidation and erythrocyte aggregation, which ensured a higher level of organ protection during cardiac surgery, faster activation of patients, and a shorter stay in the intensive care unit.