Performing cardiac surgery under cardiopulmonary bypass (CPB) and circulatory arrest (CA) provokes the development of complications caused by tissue metabolism, microcirculatory disorders, and endogenous nitric oxide (NO) deficiency. This study aimed to investigate the potential mechanisms for systemic organoprotective effects of exogenous NO during CPB and CA based on the assessment of dynamic changes in glycocalyx degradation markers, deformation properties of erythrocytes, and tissue metabolism in the experiment. A single-center prospective randomized controlled study was conducted on sheep, n = 24, comprising four groups of six in each. In two groups, NO was delivered at a dose of 80 ppm during CPB (“CPB + NO” group) or CPB and CA (“CPB + CA + NO”). In the “CPB” and “CPB + CA” groups, NO supply was not carried out. NO therapy prevented the deterioration of erythrocyte deformability. It was associated with improved tissue metabolism, lower lactate levels, and higher ATP levels in myocardial and lung tissues. The degree of glycocalyx degradation and endothelial dysfunction, assessed by the concentration of heparan sulfate proteoglycan and asymmetric dimethylarginine, did not change when exogenous NO was supplied. Intraoperative delivery of NO provides systemic organoprotection, which results in reducing the damaging effects of CPB on erythrocyte deformability and maintaining normal functioning of tissue metabolism.

This study aimed to assess the safety and potential efficacy of high-dose inhaled nitric oxide therapy for the prevention of postoperative pneumonia in cardiac surgery patients. A prospective randomised controlled pilot study included 74 patients with moderate risk of postoperative pneumonia after elective cardiac surgery under cardiopulmonary bypass. Patients were randomised into two groups. The main group (NO-group) (n = 37) received inhaled nitric oxide at a dose of 200 ppm for 30 minutes 2 times a day for 5 days or until pneumonia developed. The control group received conventional postoperative care (n = 37). The primary endpoint was the incidence of postoperative pneumonia during in-hospital stay. Preventive nitric oxide inhalations were associated with a reduced incidence of postoperative nosocomial pneumonia (2 (5.4%) cases in the main group (NO-group) vs. 9 (24.3%) cases in the control group, p = 0.046; OR = 0.178, 95% CI = 0.036-0.89)). There was no decrease in either peak expiratory flow, or peak inspiratory flow in comparison with the preoperative values in the NO-group. Inhaled nitric oxide therapy is safe. It did not lead to an increase in the incidence of acute kidney injury. High-dose inhaled nitric oxide therapy is safe and effective for the prevention of postoperative nosocomial pneumonia in cardiac surgery.

Introduction: Organoprotective effects of perioperative nitric oxide delivery towards the heart and kidneys have been demonstrated many times in cardiac surgery but information about its ability to prevent respiratory complications is extremely limited. Objective: This study aimed at evaluation of the efficacy and the safety of perioperative nitric oxide delivery for preventing respiratory complications during cardiac surgeries involving cardiopulmonary bypass in patients with an increased risk of adverse respiratory events and the identification of the risk factors towards postoperative acute respiratory. Methods: A prospective randomised controlled study included 132 cardiac surgical patients with increased risk of postoperative respiratory failure who were divided into two groups. The main group received nitric oxide at a concentration of 80 ppm throughout the operation and the first 6 hours at the postoperative period. The primary endpoint was the ratio of the partial pressure of oxygen in arterial blood to the fraction of inspired oxygen in 24 hours after the operation. Results: Patients receiving perioperative nitric oxide demonstrated significant improvements in oxygenation (paO2/FiO2 ratio, p < 0.001) in 24 hour post-surgery period that was associated with a decrease in pulmonary shunt fraction (p < 0.001), a decline of acute respiratory failure incidence (p = 0.042), and postoperative pneumonia (p = 0.013). Delivery of nitric oxide did not entail an increase in methemoglobin concentration above 5% and nitrogen dioxide above 3 ppm. In 24 h after surgery, revealed cases of acute respiratory failure were associated with blood transfusion (p = 0.033), as well as an excess of cardiopulmonary bypass duration of more than 97 min and mechanical ventilator duration of more than 628 min. Conclusion: Perioperative delivery of 80 ppm nitric oxide in cardiac surgeries involving cardiopulmonary bypass is safe and effective since it results in improved pulmonary oxygenating function and decreased pulmonary complications. In patients with an increased risk of adverse respiratory events, identified risk factors of acute respiratory failure include blood transfusion, prolonged cardiopulmonary bypass, and extended mechanical ventilation. Received 23 September 2024. Revised 2 October 2024. Accepted 7 October 2024. FundingThe study was carried out within the framework of the state assignment under the topic of basic scientific research No. 122123000017-3. Conflict of interestsThe authors declare no conflict of interest. Contribution of the authorsConception and study design: N.O. Kamenshchikov, I.V. Kravchenko, Yu.K. Podoksenov, B.N. KozlovData collection and analysis: I.V. Kravchenko, M.A. Tyo, E.A. Churilina, M.S. Kozulin, A.M. Gusakova, T.P. KalashnikovaStatistical analysis: I.V. Kravchenko, Yu.K. PodoksenovDrafting the article: I.V. Kravchenko, Yu.K. PodoksenovCritical revision of the article: N.O. Kamenshchikov, B.N. KozlovFinal approval of the version to be published: I.V. Kravchenko, Yu.K. Podoksenov, M.A. Tyo, T.P. Kalashnikova, E.A. Churilina, M.S. Kozulin, A.M. Gusakova, B.N. Kozlov, N.O. Kamenshchikov

The objective was to study the effect of the delivery of exogenous nitric oxide on the severity of apoptosis, pyroptosis, and necroptosis of the renal parenchyma after simulating cardiopulmonary bypass and cardiopulmonary bypass with circulatory arrest.Materials and Methods. 24 Altai breed rams were randomized into 4 equal groups. In the CPB and CPB+NO groups, we simulated cardiopulmonary bypass without circulatory arrest. In the CPB+CA and CPB+CA+NO groups, we simulated cardiopulmonary bypass with circulatory arrest. In the CPB+NO, CPB+CA+NO groups, NO was given perioperative in concentration of 80 ppm. In the CPB, CPB+CA groups, we supplied a standard oxygen-air mixture without NO.Results. In the CPB+CA+NO group, the TNF-α concentration was statistically significantly lower: 899 [739; 1019] ng/g compared to the CPB+CA group 1716 [1284; 2201] ng/g, p = 0.026. The remaining markers of programmed cell death did not differ between groups.Conclusions. Perioperative nitric oxide delivery reduces the expression of the extrinsic pathway of apoptosis of renal parenchyma cells in simulating operations with artificial circulation and circulatory arrest. Perioperative nitric oxide delivery at a dose of 80 ppm does not increase the processes of apoptosis, pyroptosis, and necroptosis in renal parenchyma.

HighlightsFor the first time, the incidence and timing of the development of postoperative pneumonia in patients undergoing surgical reconstruction of the aortic arch in the post-covid period were studied. Risk factors for pneumonia and predictors of the severe course of the disease in this cohort of patients were identified. The results obtained will make it possible to differentiate patients at risk of developing pneumonia from the general population of patients undergoing surgical reconstruction of the aortic arch for targeted perioperative prevention of this complication. AbstractAim. To study the incidence of nosocomial pneumonia (NP) after aortic arch surgery, and to determine the impact of perioperative factors on the risk for its development and severity of its course.Methods. A retrospective analysis of 66 case histories of patients who underwent aortic arch surgery in 2022 was carried out. The incidence and timing of the development of pneumonia were revealed, the severity of its course was assessed. The impact of the main demographic, clinical, perioperative factors on the risk for the pneumonia development and the severity of its course was studied.Results. The incidence of pneumonia after aortic arch surgery was 24.2%. A relationship between smoking (OR 1.17; 95% CI [0.23; 1.43], p = 0.007), smoking index (OR 0.99; 95% CI [0.92; 1.07], p = 0.002) and the risk of NP developing as well as between the duration of mechanical ventilation and the severity of NP was found with a univariate logistic regression analysis (OR 1.26; 95% CI [1.0; 1.59], p = 0.049).Conclusion. The risk for NP development in patients who underwent thoracic aortic surgery is associated with smoking and smoking intensity in the preoperative period. The predictor of the severe course of NP is the duration of mechanical ventilation.

INTRODUCTION: Acute kidney injury (AKI) is a common and serious complication after cardiac surgery performed under cardiopulmonary bypass (CPB). Patients with chronic kidney disease (CKD) are particularly vulnerable to cardiac surgery-associated AKI. Nitric oxide (NO) has great potential for implementing multi-organ protection in cardiac surgery. OBJECTIVES: To test the hypothesis that perioperative nitric oxide conditioning has a good safety profile and reduces the incidence of acute kidney injury during cardiac surgery under cardiopulmonary bypass in patients with chronic kidney disease. MATERIAL AND METHODS: An interim analysis of the results of the single-center prospective randomized controlled trial DEFENDER was conducted. Currently, the study included 96 patients with CKD who underwent cardiac surgery under CPB. Patients was randomized into 2 equal groups consisting of 48 people each. In the experimental group, during the operation and 6 hours after it, 80 ppm NO was delivered through the ventilator and CPB circuits. In the control group, during the operation and 6 hours after it, a standard oxygen-air mixture without NO was delivered through the ventilator and CPB circuits. The end points of the study were: the difference between groups in the incidence of AKI, the incidence of postoperative complications, outcomes and the safety profile of NO therapy. RESULTS: In the experimental group, the incidence of AKI was significantly lower compared to the control group (16,7 и 35,4 %, p = 0.036). In the experimental group, nitrogen dioxide concentration in the gas-air mixture and methemoglobin level were not above the reference range. The groups did not differ in the frequency of blood transfusions, the amount of postoperative bleeding, or the number of platelets on the first day after surgery. CONCLUSIONS: Perioperative nitric oxide conditioning has a good safety profile and reduces the incidence of acute kidney injury during cardiac surgery with CPB in patients with chronic kidney disease.