Intravenous sildenafil for perioperative management of patients with pulmonary artery hypertension in congenital heart surgery − a prospective randomized study

Background In congenital heart disease (CHD), pulmonary artery hypertension is complicated by dysfunctional endogenous production of nitric oxide by pulmonary endothelium. Elevated activity of phosphodiesterase type 5 has also been demonstrated in such cases, and is amplified by cardiopulmonary bypass in postoperative children. Treatment with pulmonary vasodilators like milrinone, oral sildenafil, inhaled nitric oxide, and epoprostenol has been used with varying degrees of success. The current study aimed to investigate the efficacy and safety of intravenous sildenafil in postoperative children with increased pulmonary vascular resistance due to CHD.Methodology and results A prospective, randomized controlled trial was conducted in which 100 children of CHD with pulmonary artery hypertension were studied. All were randomly divided in two groups (S=sildenafil and C=control). Group-S patients received intravenous sildenafil (1.6 mg in 24 h), while in group C, similar amount of placebo (normal saline) infusion over 24 h started after removing aortic cross-clamp. In both the groups, the rest of the anesthetic and inotropic management was similar as per the institute’s protocol. Intravenous sildenafil more effectively improved PO2 : FiO2 (P : F) ratio (P<0.0001), reduced pulmonary artery systolic pressure (P<0.0001), ventilation time (in h) (S=21.36±4.11, C=30.14±11.01, P<0.0001), length of ICU stay (in h) (S=68.74±10.11, C=87.56±27.78, P<0.0001), and length of hospital stay (in days) (S=10.5±1.23, C=12.46±1.99, P<0.0001).Conclusion Intravenous sildenafil is a safe and effective pulmonary vasodilator in the perioperative setting in children with CHD.