Addition of dexmedetomidine prolongs duration of vasodilation induced by sympathetic block with mepivacaine in dogs.
OBJECTIVE
The aim of this study was to examine the duration of vasodilation induced by sympathetic block with the addition of dexmedetomidine to mepivacaine.


METHODS
We measured right and left brachial artery blood flow (BABF) before and after stellate ganglion block used as a sympathetic block in dogs. The experimental protocol was designed as follows: (1) left stellate ganglion block using 1.0 mL 0.5% mepivacaine (n = 8), (2) left stellate ganglion block using the addition of dexmedetomidine 0.5 microg to 1.0 mL 0.5% mepivacaine (n = 8), and (3) left stellate ganglion block using the addition of dexmedetomidine 0.5 microg to 1.0 mL physiological saline solution (n = 8).


RESULTS
Left stellate ganglion block with mepivacaine alone increased left BABF significantly from 5 minutes through 50 minutes after the block (baseline, 100%; peak at 10 minutes after SGB, 181 +/- 27%; P <.01). Left stellate ganglion block with the addition of dexmedetomidine to mepivacaine induced a significant increase of left BABF from 5 minutes through 90 minutes after the block (baseline, 100%; peak at 10 minutes after SGB, 174 +/- 36%; P <.01). Left and right BABF did not change significantly after stellate ganglion block with dexmedetomidine only. Right BABF decreased significantly after left stellate ganglion block with mepivacaine alone or the addition of dexmedetomidine to mepivacaine throughout the study.


CONCLUSIONS
The addition of dexmedetomidine prolongs the duration of vasodilation induced by stellate ganglion block with mepivacaine used for sympathetic block in dogs.
Department of Anesthesiology, Dokkyo University School of Medicine, Tochigi, Japan.
Masatomo
M
Tezuka
Toshimitsu
T
Kitajima
Shigeki
S
Yamaguchi
Yoshiyuki
Y
Kimura
Shinsuke
S
Hamaguchi
D018712:Analgesics, Non-Narcotic / Q000494:pharmacology*; D000704:Analysis of Variance; D000779:Anesthetics, Local / Q000008:administration & dosage*; D000818:Animals; D001340:Autonomic Nerve Block / Q000379:methods*; D001783:Blood Flow Velocity / Q000187:drug effects; D001784:Blood Gas Analysis / Q000379:methods; D001794:Blood Pressure / Q000187:drug effects; D001916:Brachial Artery / Q000187:drug effects; D020927:Dexmedetomidine / Q000494:pharmacology*; D004285:Dogs; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D008619:Mepivacaine / Q000008:administration & dosage*; D013997:Time Factors; D014664:Vasodilation / Q000187:drug effects*
D018712:Analgesics, Non-Narcotic; D000779:Anesthetics, Local; D020927:Dexmedetomidine; D008619:Mepivacaine