Inhaled prostacyclin following surgical repair of congenital heart disease--a pilot study

BACKGROUND: The development of additional therapies for the treatment of pulmonary hypertension would be a significant advancement in the treatment of congenital heart disease. Recently, studies have found inhaled prostacyclin (PGI2) is an effective pulmonary vasodilator, comparable with nitric oxide. In this prospective interventional pilot study, we examined the physiologic effects of inhaled PGI2 in children with congenital heart disease and pulmonary hypertension. METHODS: Six children (median age 6 months, range 5 to 21 months) with congenital heart disease and preoperative pulmonary hypertension (mean pulmonary artery pressure [MPAP] greater than 50% systemic) received a 15-minute course of inhaled PGI2 intraoperatively postrepair. The inhaled PGI2 was delivered by aerosolizing the IV formulation (Flolan, Glaxo-Wellcome) to achieve a dose of 50 ng/kg/min. Physiologic parameters measured during the medication period were compared with measurements taken during two 15-minute baseline periods before and after the medication period. RESULTS: Inhaled PGI2 significantly reduced the mean pulmonary artery pressure from 25 +/- 3 to 21 +/- 3 (p < 0.01) and improved the PaO2/FiO2 ratio from 275 +/- 181 to 433 +/- 285 (p = 0.01). There were no significant changes in systemic blood pressure, heart rate, or cardiac index. CONCLUSIONS: Children with congenital heart disease and pulmonary hypertension may benefit from inhaled PGI2. Inhaled PGI2 reduced pulmonary blood pressures and improved oxygenation in this small study. PGI2 acts through cyclic adenosine monophosphate mediated pulmonary vasodilation, a mechanism different from nitric oxide. In children with inadequate response to nitric oxide, inhaled PGI2 may be a useful alternative pulmonary vasodilator.