Methods: Oral sildenafil (1 mg/kg, 4 times daily) was added to the treatment of 18 of 21 patients who had started iNO therapy intraoperatively, on the postoperative first day. The medical records of the patients were retrospectively evaluated with respect to the clinical status of rebound pulmonary artery hypertension, entubation time, duration of intensive care unit stay, and early and late mortality.

Results: Early mortality was seen in four (22.2%) of 18 patients with the sildenafil treatment protocol. Two (11.1%) deaths were due to low cardiac output on the postoperative first day, and the remaining two (11.1%) deaths were due to severe rebound pulmonary hypertensive crisis on the postoperative sixth and ninth days. In 14 (77.8%) of the patients, no rebound pulmonary hypertensive crisis was seen after the discontinuation of iNO with the oral sildenafil treatment.

Conclusion: The prophylactic use of sildenafil to facilitate iNO withdrawal can be beneficial in the prevention of rebound pulmonary hypertension following congenital cardiac surgery. Randomized controlled trials are needed to evaluate the safety and efficacy of the prophylactic use.