Sildenafil in the Treatment of Postoperative Hypoxemia with High Resistance in Cyanotic Congenital Heart Disease

This study was designed to determine the effect of sildenafil treatment on postoperative hypoxemia with high resistance in cyanotic congenital heart disease. A total of 247 cases of cyanotic congenital heart disease were operated on from May 2006 to August 2014. Only 45 cases exhibited postoperative hypoxemia after symptomatic treatment. Sildenafil at doses of 0.30-5 mg/kg every 6 h was administered in 24 cases while the other 21 were administered a placebo (the control group). The partial pressure of oxygen in arterial blood (PaO₂), systolic blood pressure, pulmonary arterial pressure and positive inotropic drugs score were evaluated at four time points including before (T1), 1 h (T2) and 1 day (T3) after treatment and when the ventilator was disconnected (T4). Furthermore, we compared the mechanical ventilation time between the two groups. Finally, there was one death in the placebo group while the others were cured. Compared with the placebo group, in the sildenafil group, the PaO₂ rebounded faster and the pulmonary arterial pressure decreased significantly; furthermore, there were statistically significant differences from time point T2 between both groups (p<0.001). The systolic blood pressure rose slowly and there were statistically significant differences between both groups from time point T3 (p<0.001). The representations of the positive inotropic drug scores were obviously different between the two groups. The sildenafil group scores decreased soon and maintained this trend. The placebo group scores initially increased and then began to decline 1 day after treatment, but the final score was higher than that of the sildenafil group. Compared with the placebo group, in the sildenafil group, the respiratory and heart functions recovered rapidly and the patient’s stay on the mechanical ventilation was shorter (67.52±16.88 Vs. 44.25±13.39 h, p = 0.001). Therefore, sildenafil reduced pulmonary vascular resistance and obviously corrected the postoperative hypoxemia in cyanotic congenital heart disease.