Olprinone is a selective phosphodiesterase 3 (PDE3) inhibitor. Olprinone is used as cardiotonic agent with positive inotropic and vasodilating effects. Olprinone has been reported to improve microcirculation and attenuate inflammation. Olprinone is often used to increase cardiac output after cardiopulmonary bypass (CPB). Olprinone was infused at a rate of 0.2 μg/kg/min when weaning from CPB was started. Olprinone has also shown potent antioxidative and anti-inflammatory effects in the meconium-induced oxidative lung injury.