Prostacyclin (epoprostenol): its effect on canine splanchnic blood flow during hemorrhagic shock

Prostacyclin (epoprostenol, prostaglandin I2) is a vasodilator of the splanchnic circulation during normotensive states. To confirm the persistence of its effects after hemorrhagic shock, six anesthetized, previously splenectomized, adult mongrel dogs were subjected to hemorrhagic shock using a modified Wigger's technique in which a mean arterial pressure of 30 mm Hg was maintained until 25% of the shed blood spontaneously returned. The animals were randomly resuscitated with normal saline solution or a similar volume of saline solution containing prostacyclin. Organ blood flow was calculated by measuring the distribution of radioactively tagged microspheres. During shock, blood flows to the liver, small intestine, pancreas, and carcass were reduced. During a 60-minute infusion, prostacyclin selectively caused a significant increase in hepatic arterial blood flow. This improvement in arterial blood flow may prove beneficial in the clinical management of hemorrhagic shock.