Comparison of 0.25% levobupivacaine, 0.25% bupivacaine, and 0.125% bupivacaine for duration and magnitude of action in peripheral arterial blood flow induced by sympathetic block in dogs.

Abstract

The aim of this study is to compare 0.25% levobupivacaine with 0.25% bupivacaine and 0.125% bupivacaine to examine the duration and magnitude of vasodilative effect induced by sympathetic block. We measured mean arterial pressure (MAP), heart rate (HR), and right and left brachial-artery blood flow (BABF) before and after cervicothoracic sympathetic block in 24 dogs. The experimental protocol was designed as follows: (1) left cervicothoracic sympathetic block with 1.0 mL of 0.25% levobupivacaine (n = 8), (2) left cervicothoracic sympathetic block with 1.0 mL of 0.25% bupivacaine (n = 8), and (3) left cervicothoracic sympathetic block with 1.0 mL of 0.125% bupivacaine (n = 8). MAP and HR did not change significantly throughout the study in either group. Left cervicothoracic sympathetic block with 0.25% levobupivacaine increased left BABF significantly from 5 minutes through 80 minutes after the block (baseline, 100%; peak at 10 minutes after the block, 185 +/- 35%; P <.01). Left cervicothoracic sympathetic block with 0.25% bupivacaine increased left BABF significantly from 5 minutes through 100 minutes after the block (baseline, 100%; peak at 10 minutes after the block, 251 +/- 47%; P < .01). Left cervicothoracic sympathetic block with 0.125% bupivacaine increased left BABF significantly from 5 minutes through 80 minutes after the block (baseline, 100%; peak at 10 minutes after the block, 155 +/- 20%; P < .01). 0.25% Levobupivacaine may have a lower potency compared with 0.25% bupivacaine in sympathetic block in dogs.