The new nitric oxide generator for delivery to the extracorporeal circuit: technical and medical characteristics, experimental and clinical studies of its effectiveness and safety

A medical plasma-chemical apparatus for synthesizing nitric oxide (NO) has been developed for the first time. It is designed to deliver it directly into the extracorporeal circuit of heart-lung machine and extracorporeal membrane oxygenation (ECMO) machines. This paper presents the technical characteristics of the apparatus, the results of its experimental use, and clinical studies during CPB surgeries. In the apparatus’s plasma-chemical reactor, the primary synthesis of NO was achieved in the plasma of diffuse low-current (<1 A) microsecond-duration discharges uniformly distributed within the annular discharge gap. This ensured a long service life of the electrode system—up to 6.000 hours—and low levels of unwanted impurities. Experimental results showed that the oxygenator with a polypropylene hollow fiber membrane retained its mass-transfer properties in the presence of NO at a concentration of 500 ppm for 6 hours, with no signs of chemical interaction between polypropylene and NO. Analysis of the surface condition of hollow fiber membrane samples from oxygenators revealed a significantly lower incidence of fibrin deposits when NO was administered via CPB. Clinical studies have shown that administering NO to the extracorporeal circuit exerted an antioxidant effect, reduced oxidative stress, maintained high ATP levels in red blood cells, effectively prevented increased red blood cell aggregation, and had a protective effect on endothelial function during prolonged CPB. Perioperative administration of NO was associated with a statistically significant reduction in the incidence of acute kidney injury within 7 days postoperatively and a protective effect on the myocardium.