Brazilian Journal of Anesthesiology
https://bjan-sba.org/article/doi/10.1590/S0034-70942013000200004
Brazilian Journal of Anesthesiology
Scientific Article

Efeitos antinociceptivos, analgésicos e histopatológicos de dexmedetomidina e bupivacaína intratecal em rato

Anti-nociceptive, analgesic and pathohistological effects of intrathecal dexmedetomidine and bupivacaine in rats

Baş; ar Erdivanli; Murat Altun; Özlem K Sezen; Serhan A Çolakoğ; lu

http://dx.doi.org/10.1590/S0034-70942013000200004 Braz J Anesthesiol, vol.63, n2, p.183-187, 2013
PDF Português
PDF English
Downloads: 1
Views: 929

Resumo

JUSTIFICATIVA E OBJETIVOS: Este estudo investigou os efeitos analgésicos e nociceptivos da adição de dexmedetomidina à bupivacaína em anestesia do neuroeixo usando os testes de retirada da cauda (tail-flick [TF]) e da placa quente (hot-plate [HP]) e microscopia de luz para as alterações histopatológicas de nervos espinhais e raízes nervosas. MÉTODOS: Quarenta ratos Sprague-Dawley anestesiados, machos, foram cateterizados intratecalmente. Os valores basais dos testes TF e HP foram medidos antes e depois do cateterismo. Trinta e seis ratos cateterizados com sucesso foram distribuídos em quatro grupos. O Grupo B recebeu 10 µg de bupivacaína, o Grupo BD3 recebeu 10 µg de bupivacaína + 3 µg de dexmedetomidina, o Grupo BD10 recebeu 10 µg de bupivacaína + 10 µg de dexmedetomidina e o Grupo Controle recebeu 10 µL de líquido cefalorraquidiano artificial. Os testes TF e HP foram feitos entre cinco e 300 minutos a partir da administração das drogas. Vinte e quatro horas após a administração, os ratos foram sacrificados e retiradas as medulas espinhais e raízes nervosas para investigação patológica. RESULTADOS: Os valores basais dos testes TF e HP não foram estatisticamente diferentes entre os grupos (6,8 ± 0,15 s). As latências de TF e HP no Grupo Controle não apresentaram alteração significativa durante o estudo. Os resultados dos testes TF e HP mostraram que a adição de 3 e 10 µg de dexmedetomidina causou um aumento dose-dependente na duração e amplitude do efeito analgésico e nociceptivo de bupivacaína (TF: 37,52 ± 1,08%, 57,86 ± 1,16%, respectivamente; HP: 44,24 ± 1,15%, 68,43 ± 1,24%, respectivamente). CONCLUSÕES: Não houve alterações histopatológicas aparentes em pelo menos 24 horas após a administração intratecal da dose única de dexmedetomidina (3 µg e 10 µg). Dexmedetomidina adicionado à bupivacaína para raquianestesia melhora a analgesia e prolonga a duração do bloqueio.

Palavras-chave

ANESTESIA, Regional, raquianestesia, ANESTÉSICOS, Local, bupivacaína, ANALGÉSICOS, Dexmedetomidina, DOR; ANIMAL, Rato

Abstract

BACKGROUND AND OBJECTIVES: This study investigates analgesic and nociceptive effects of adding dexmedetomidine to bupivacaine neuraxial anesthesia through Tail-flick (TF) and Hot-plate (HP) tests and the pathohistological changes on spinal nerves and nerve roots through light microscopy. METHODS: Forty anesthetized, male Sprague-Dawley rats were intrathecally catheterized. Basal values of TF and HP tests were measured before and after catheterization. Thirty-six successfully catheterized rats were assigned to four groups. Group B received 10 µg bupivacaine, Group BD3 received 10 µg bupivacaine + 3 µg dexmedetomidine, Group BD10 received 10 µg bupivacaine + 10 µg dexmedetomidine and Control group received 10 µL volume of artificial cerebrospinal fluid. TF and HP tests were performed between the 5th and 300th minutes of drug administration. Twenty-four hours after administration of drugs, rats were sacrificed and spinal cord and nerve roots were removed for pathological investigation. RESULTS: Baseline values of the TF and HP tests were not statistically different among the groups (6.8 ± 0.15 s). TF and HP latencies in the Control group did not change significantly during the study. TF and HP test results showed that adding 3 and 10 µg dexmedetomidine caused a dosedependent increase in duration and amplitude of analgesic and nociceptive effect of bupivacaine (TF: 37.52 ± 1.08%, 57.86 ± 1.16% respectively, HP: 44.24 ± 1.15%, 68.43 ± 1.24% respectively). CONCLUSIONS: There were no apparent pathohistological changes at least 24 hours after the intrathecal administration of a single dose of dexmedetomidine 3 µg and 10 µg. Dexmedetomidine added to bupivacaine for spinal block improves analgesia and prolongs block duration.

Keywords

Bupivacaine, Dexmedetomidine, Pain Measurement, Rats, Sprague-Dawley, Anesthesia, Spinal

Referencias

GR Charles BB. Local anesthetics. Miller's anesthesia. 2005:573-604.

Sakura S. Research on local anesthetic neurotoxicity using intrathecal and epidural rat models. J Anesth. 2007;21(4):533-534.

Sakura S, Kirihara Y, Muguruma T. The comparative neurotoxicity of intrathecal lidocaine and bupivacaine in rats. Anesth Analg. 2005;101(2).

Bharti N, Madan R, Mohanty P. Intrathecal midazolam added to bupivacaine improves the duration and quality of spinal anaesthesia. Acta Anaesthesiol Scand. 2003;47(9):1101-1105.

Karaman S, Kocabas S, Uyar M. The effects of sufentanil or morphine added to hyperbaric bupivacaine in spinal anaesthesia for caesarean section. Eur J Anaesthesiol. 2006;23(04):285-291.

Tan PH, Chia YY, Lo Y. Intrathecal bupivacaine with morphine or neostigmine for postoperative analgesia after total knee replacement surgery. Can J Anesth. 2001;48(6):551-556.

Togal T, Demirbilek S, Koroglu A. Effects of s (+) ketamine added to bupivacaine for spinal anaesthesia for prostate surgery in elderly patients. Eur J Anaesthesiol. 2004;21(3):193-197.

Kanazi G, Aouad M, Jabbour Khoury S. Effect of low dose dexmedetomidine or clonidine on the characteristics of bupivacaine spinal block. Acta Anaesthesiol Scand. 2006;50(2):222-227.

Yoshitomi T, Kohjitani A, Maeda S. Dexmedetomidine enhances the local anesthetic action of lidocaine via an -2a adrenoceptor. Anesth Analge. 2008;107(1).

Yaksh TL, Rudy TA. Chronic catheterization of the spinal subarachnoid space. Physiol Behav. 1976;17(6):1031-1036.

Reed D, Withrow C, Woodbury D. Electrolyte and acidbase parameters of rat cerebrospinal fluid. Exp Brain Res. 1967;3(3):212-219.

Silva G, Feeney C, Mills L. A novel and rapid method for culturing pure rat spinal cord astrocytes on untreated glass. J Neurosci Meth. 1998;80(1):75-79.

Bancroft JD, Cook HC, Turner DR. Book manual of histological techniques. 1984:18-22.

Weil A. A rapid method for staining myelin sheaths. Arch Neurol Psychiatr. 1928;20(2):392.

Ishii H, Kohno T, Yamakura T. Action of dexmedetomidine on the substantia gelatinosa neurons of the rat spinal cord. Eur J Neurosci. 2008;27(12):3182-3190.

Gupta R, Verma R, Bogra J. A comparative study of intrathecal dexmedetomidine and fentanyl as adjuvants to bupivacaine. J Anaesthesiol, Clinical Pharmacology. 2011;27(3).

Brummett CM, Hong EK, Janda AM. Perineural dexmedetomidine added to ropivacaine for sciatic nerve block in rats prolongs the duration of analgesia by blocking the hyperpolarization-activated cation current. Anesthesiology. 2011;115(4).

Calasans Maia JA, Zapata Sudo G, Sudo RT. Dexmedetomidine prolongs spinal anaesthesia induced by levobupivacaine 0.5% in guinea pigs. J Pharm Pharmacol. 2005;57(11):1415-1420.

Brummett CM, Padda AK, Amodeo FS. Perineural dexmedetomidine added to ropivacaine causes a dose-dependent increase in the duration of thermal antinociception in sciatic nerve block in rat. Anesthesiology. 2009;111(5).

South SM, Edwards SR, Smith MT. Antinociception versus serum concentration relationships following acute administration of intravenous morphine in male and female sprague-dawley rats: differences between the tail flick and hot plate nociceptive tests. Clin Exp Pharmacol Physiol. 2009;36(1):20-28.

Esmaoglu A, Yegenoglu F, Akin A. Dexmedetomidine added to levobupivacaine prolongs axillary brachial plexus block. Anesth Analg. 2010;111(6).

5dd42b800e8825e429c63493 rba Articles
Links & Downloads
2352-2291 (Electrónico) 0104-0014 (Impreso)
Braz J Anesthesiol ©2024 Todos los derechos reservados.

Braz J Anesthesiol

Share this page
Page Sections