Prostacyclin levels during orthotopic liver transplantation

Many anesthesia providers involved in orthotopic liver transplantation (OTL) have become increasingly aware of the incidence of hypotension immediately following revascularization of the donor liver. Postreperfusion syndrome (PRS) is usually characterized by a decrease in systemic blood pressure of at least 30 torr with a duration of 5 minutes or more. Several researchers have suggested that the etiology of this hypotension may be related to acute hyperkalemia, acidosis, hypothermia, reflex systemic vasodilation, or some yet unidentified prostaglandin liberated from the gut at reanastomosis. The potential role of prostacyclin as the primary etiologic agent responsible for this syndrome was studied. Serum prostacyclin measurements were obtained in seven patients 1 minute before and 5 minutes after revascularization. Coincident measures were taken of preselected cardiovascular parameters. Five patients demonstrated increased levels of prostacyclin during clamping of the portal vein and four experienced significant hypotension at reperfusion. In the five patients demonstrating hypotension, a decrease in heart rate and systemic vascular resistance and an increase in cardiac output and PCWP was noted. It is concluded that one or more endogenous prostacyclins may play an important role in the etiology of postreperfusion syndrome.