Definition A decrease in prostaglandin E2 (PGE2), along with exposure to oxygenated blood, causes the ductus arteriosus to close after birth. PGE1 (0.1 ug/kg/min) maintains ductus patency (and in some cases can reopen a closed duct), by directly acting on vascular smooth muscle. PGE1 is essential in patients with HLHS, AS, interupted arch, in which […]