The First Clinical Application of a Therapy Device for Nitric Oxide Synthesis from Atmospheric Air

Abstract

Precapillary pulmonary hypertension (PH) is a difficult problem in the perioperative period of cardiac surgery. In these situations, there is a high risk of PH decompensation with the development of right ventricular failure and cardiogenic shock. In the intensive care of precapillary PH, pulmonary vasodilators are of great importance. Inhaled nitric oxide (NO) is known as the “gold standard” of intensive therapy for decompensation of precapillary PH, including in the postoperative period of cardiac surgery. In modern medical practice, NO is produced in chemical factories and delivered to hospitals in cylinders. The high cost of NO, feeding and dosing devices, and possible difficulties in the purchase and delivery of cylinders are important limitations of the widespread use of this therapy. The world’s first NO inhalation therapy device, which synthesizes NO by the method of nitrogen oxidation in a nonequilibrium plasma of a pulsed, periodic, diffuse electric discharge in air, was invented in Russia. The aim of this study was to evaluate the clinical efficacy and safety of the method of synthesis of NO from atmospheric air in the postoperative period of cardiac surgery. A total of 110 patients were enrolled in the single-center cohort study with retrospective controls. The results of the application of the method of synthesis of NO from atmospheric air using the AIT-NO-01 device (the main group) were compared with those obtained from the retrospective control group when using a device (NOxBOX Mobile, Bedfont, UK) for dosing NO from cylinders. A total of 55 patients were included in the main group and 55 in the retrospective control group. Inclusion criteria were having undergone cardiac surgery, mean pulmonary artery pressure (PAPm) ≥25 mmHg, and pulmonary artery wedge pressure (PAWP) ≤15 mmHg. All patients underwent surgical interventions of the heart. In order to control the effectiveness of NO inhalation therapy, a complex of hemodynamic parameters as well as indicators of the clinical course of the postoperative period were evaluated. There were no significant differences between the comparison groups in terms of the baseline characteristics of the patients, pulmonary circulation parameters, and the structure of the surgical procedures. After 1 h of NO inhalation in the main group, there was a 35% decrease in pulmonary vascular resistance (PVR) and a 16% decrease in PAPm. In the control group, there was a decrease in PVR by 40% and a decrease in PAPm by 19%. Inhalation of NO did not affect the systemic circulation hemodynamics both in the main and in the control groups. The median duration of mechanical ventilation (MV) was 7.3 (4.5; 13.8) h, and the median length of stay in the ICU was 23.2 (21.3; 46) h in the main group. In the retrospective control group, the median duration of MV was 8.2 (5; 14.1) h, and the length of ICU stay was 24 (22, 45.3) h; no differences were found between the two groups. NO synthesized from room air significantly reduced PVR and PAPm in patients with precapillary pulmonary hypertension after cardiac surgery. There were no significant differences in the effect on pulmonary circulation, clinical data, and side effects between the methods of synthesis of NO from room air and dosing from balloons.