Effect of nitric oxide delivery on energy supply of renal tissue in cardiopulmonary bypass: an experimental study

Introduction. Acute kidney injury is a common complication of cardiac surgery with cardiopulmonary bypass. Ischemic-reperfusion injury, systemic inflammation, oxidative stress, and other factors that occur during cardiopulmonary bypass lead to disruption of energy supply and death of kidney tissue cells. Delivery of nitric oxide is a promising method of nephroprotection during cardiosurgical operations with cardiopulmonary bypass. Aim: To study the parameters of energy supply of the renal tissue during cardiopulmonary bypass with nitric oxide delivery in the experiment. Material and Methods. A prospective controlled experimental study was performed on 12 rams. Animals were included in 2 equal groups at a ratio of 1:1. In the main group, nitric oxide was delivered at a dose of 80 ppm immediately after tracheal intubation and within 90 minutes of cardiopulmonary bypass (main group, n = 6). In the control group, mechanical ventilation and cardiopulmonary bypass were performed according to standard protocols (control group, n = 6). Biopsy specimens of kidney tissue were taken 1 hour after weaning from cardiopulmonary bypass. Energy supply was assessed (according to the tissue concentration of adenosine triphosphate (ATP) and lactate). Results. Delivery of nitric oxide was not accompanied by tissue perfusion aberration during cardiopulmonary bypass (CPB). The level of free hemoglobin in both groups was statistically significantly higher 1 hour after cardiopulmonary bypass compared with the stages of intubation – p < 0.000... and the beginning of CPB – p < 0.000... The ATP value significantly differed between groups and amounted in the control group 3.7 ± 0.62 nmol/g; in the main group 6.8 ± 1.11 nmol/g, р = 0.00011. The lactate concentration did not differ statistically significantly between the groups and amounted to: in the control group 12.9 ± 3.71 nmol/g; in the main group 10.2 ± 2.14 nmol/g, р = 0.1502. Conclusion: Delivery of nitric oxide improved the parameters of energy supply of the renal tissue during cardiopulmonary bypass in the experiment.