ObjectiveTo explore the hemodynamic effects of inhaled nitric oxide (iNO) on postoperative hemodynamic in patients with cyanotic congenital heart disease (CHD) combined with decreased pulmonary blood flow.MethodsFrom 2014 to 2018, there were 1 764 patients who received corrective repair of cyanotic CHD with decreased pulmonary blood flow in the Department of Pediatric Cardiac Surgery of Fuwai Hospital. We included 61 patients with the ratio of right ventricular systolic pressure to systolic blood pressure (SBP) ≥75% after weaning from cardiopulmonary bypass. There were 41 males and 20 females, with the age of 20.5 (9.0, 39.0) months and weight of 12.5±7.8 kg. The patients were divided into two groups: a conventional group (33 patients, conventional therapy only) and a combined therapy group (28 patients, iNO combined with conventional therapy). The hemodynamics during the first 24 hours after iNO therapy and the in-hospital outcomes of the two groups were investigated and compared.ResultsThere was no statistical difference between the two groups in demographic characteristics and surgical parameters (P>0.05). The hemodynamic effects of iNO within 24 hours included the decrease in the vasoactive inotropic score (VIS, 21.6±6.6 vs. 17.3±7.2, P=0.020) along with the increase in blood pressure (SBP: 73.7±9.7 mm Hg vs. 90.8±9.1 mm Hg, P<0.001) , the decrease in central venous pressure (10.0±3.1 mm Hg vs. 7.9±2.1 mm Hg, P=0.020), the decrease in lactate (2.2±1.7 mmol/L vs. 1.2±0.5 mmol/L, P<0.001) and increase in urine output [2.8±1.7 mL/(kg·h) vs. 4.9±2.2 mL/(kg·h), P<0.001]. The decrease of VIS at 24 h after the surgery in the conventional therapy group was not statistically significant (22.1±7.9 vs. 20.0±8.5, P=0.232). Besides, we discovered that the need for renal replacement therapy (RRT) was less in the combined therapy group than that in the conventional therapy group, especially in the moderate complicated surgery [risk adjustment in congenital heart surgery (RACHS-1) ≤3] subgroup (9.5% vs. 40.7%, P=0.016).ConclusionIn pediatric patients after corrective repair of cyanotic and pulmonary blood follow decreased CHD with increased pulmonary vascular resistance, iNO combined with conventional therapy can improve the hemodynamics effectively. Compared with the conventional therapy, the combined therapy with iNO can decrease the VIS and the need for RRT, which is beneficial to the postoperative recovery of patients.