Comparison of stellate ganglion block with intravascular infusion of prostaglandin E1 on brachial artery blood flow in dogs.

We sought to determine whether sympathetic blockade or infusion of prostaglandin E1 (PGE1) is better for vasodilation. We measured brachial artery blood flow (BABF) in 10 mongrel dogs using an ultrasonic time flowmeter to compare the effects of stellate ganglion block (SGB) and intravascular infusion of PGE1. The experimental protocol was designed as follows: 1) intravenous (IV) infusion of PGE1 at a rate of 10 ng x kg(-1) x min(-1) for 10 min, 2) IV infusion of PGE1 at a rate of 150 ng x kg(-1) x min(-1) for 10 min, 3) intraarterial infusion of PGE1 at a rate of 0.1 ng x kg(-1) x min(-1) for 10 min, 4) SGB with 0.5% mepivacaine 1.0 mL was used as a sympathetic blockade. These procedures were successively performed on each dog. Mean arterial pressure (MAP), heart rate (HR), and BABF were measured before and after each procedure for 40 min. MAP and HR did not change significantly after the procedures. BABF increased significantly after IV infusion of PGE1 150 ng x kg(-1) x min(-1), intraarterial infusion of PGE1 and SGB, reaching maximums of 157%, 174%, and 171% 10 min after IV infusion of PGE1 150 ng x kg(-1) x min(-1), intraarterial infusion of PGE1 and SGB compared with the prevalues, respectively. These data indicate that sympathetic blockade may produce the same vasodilation as IV infusion of PGE1 150 ng x kg(-1) x min(-1) and intraarterial infusion of PGE1 0.1 ng x kg(-1) x min(-1). Intravascular infusion of PGE1 could provide clinically equivalent vasodilation without the complications associated with SGB.