Permanent Intraoperative Nitric Oxide Inhalation for Adults with High Pulmonary Hypertension during Heart Valve Surgery with Cardiopulmonary Bypass

Vladimir Pichugin ¹, Stepan Domnin ², Alexander Medvedev ¹, Alishir Gamzaev ², Ilgiz Seyfetdinov ²

¹ Nizhny Novgorod State Medical Academy, Nizhny Novgorod, Russia; ² Specialized Clinical Cardiosurgical Hospital, Nizhny Novgorod, Russia;

Date, time and location: 2018.05.26 13:30, Press Hall, 2F

Abstract

Objective. The aim of the study was to evaluate the effectiveness of permanent intraoperative NO inhalation in adults with high pulmonary hypertension during heart valves surgery with cardiopulmonary bypass.

Material and methods. The study included 67 patients (mean age 58.9 ± 1.9), underwent replacement or plastic correction of heart valves. The mean pulmonary artery pressure was 42.2 ± 1.5 mm Hg. All patients were randomized into three groups: the first (27) – control group; the second (15) group - intraoperative NO inhalation (20-25 ppm) before and after CPB; the third (25) group – permanent  NO inhalation (20-25 ppm) before, during and after CPB, during CPB - pulmonary artery perfusion and lungs ventilation with NO were performed. NO generator “TIANOX” (Russia) was used as a constant source of nitric oxide. This machine is able to generate NO directly from atmosphere air. A comparative evaluation included  hemodynamic changes, myocardial contractility function and  the functional lungs parameters.

Results. The onset of NO inhalation resulted in a significant decrease in mean pulmonary artery pressure, an average of 18.0%, the left ventricle contractility parameters were stable. Intraoperative NO inhalation was accompanied by a significantly lower alveolar-arterial oxygen difference during operation, a significantly higher oxygenation index from the onset of NO inhalation. A significantly higher oxygenation index, significantly lower intrapulmonary shunt parameter after CPB, and the preservation of the initial values ​​of pulmonary compliance at all stages of the operation were registered in third group. No adverse effects of permanent NO inhalation were observed.

Conclusion. The permanent intraoperative NO inhalation in combination with pulmonary artery perfusion and ventilation during CPB had a number of undeniable advantages over NO inhalation before and after CPB technique. The effectiveness of lungs protection during CPB was better in these patients, but larger randomized trials are needed for evaluation of this technique.