Nitric Oxide in Cardiopulmonary Bypass for Renal Protection in Cardiac Surgery

The aim of this work is to study nephroprotective effects of nitric oxide (NO) supplementation to the cardiopulmonary bypass (CPB) circuit during cardiac surgery with normothermic CPB in adult patients. The prospective randomized study is performed in the settings of Federal Cardiology Center. A total of 96 adult patients who underwent cardiac surgery with CPB are enrolled in the study. Patients are randomized to two groups: main group receive NO treatment; control group undergoes sham procedure. In the main group, NO is supplied to the CPB line in a dose of 40 ppm throughout the entire CPB period. The primary endpoint is the frequency of acute kidney injury (AKI). The secondary endpoints are urine output during CPB; uNGAL level 4 h after surgery; plasma concentration of free hemoglobin (Hb); concentrations of NO metabolites (nitrite (NO2-) and nitrate (NO3-)) and the total concentration of metabolites of NO (NOx, μM/mL) in blood plasma in the intraoperative period; concentration of proinflammatory (TNF-α, IL-1β, -6, and -8) and anti-inflammatory mediators (IL-1ra, IL-4) in blood plasma in the intraoperative period. Cumulative fluid balance, diuresis, and Lasix doses are assessed within the first 48 h of the postoperative period. The dynamics of serum creatinine is assessed during the first week following the intervention.

Inclusion criteria

Age above 18 years; planned primary cardiac intervention with cardiopulmonary bypass including coronary artery bypass grafting, valve surgery, and surgical reconstructions of the left ventricle.

Exclusion criteria

Preoperative anemia; the intake of nephrotoxic drugs or the use of X-ray contrast within 72 h before surgery; active phase of endocarditis; emergency surgery; chronic kidney disease; hematologic diseases accompanied by hemolysis; complications of the surgery and the early postoperative period.