Brazilian Journal of Anesthesiology
https://bjan-sba.org/article/doi/10.1590/S0034-70942008000300006
Brazilian Journal of Anesthesiology
Scientific Article

Comparação das alterações histológicas da medula espinal e neurológicas de cobaias após anestesia subaracnóidea com grandes volumes de bupivacaína racêmica, de mistura com excesso enantiomérico de 50% de bupivacaína (S75-R25) e de levobupivacaína

Comparison of histologic spinal cord and neurologic changes in guinea pigs after subarachnoid block with large volumes of racemic bupivacaine, 50% enantiomeric excess bupivacaine (S75-R25), and levobupivacaine

Paulo de Oliveira Vasconcelos Filho; Irimar de Paula Posso; Mariza Capelozzi; Vera Luiza Capelozzi

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Resumo

JUSTIFICATIVA E OBJETIVOS: A levobupivacaína apresenta menos efeitos colaterais sobre o sistema nervoso central do que os induzidos pela bupivacaína racêmica; entretanto, o efeito anestésico é menos intenso. Foi realizado estudo experimental para comparar efeitos adversos de grandes volumes de bupivacaína, de bupivacaína S75-R25 e de levobupivacaína quando injetados no espaço subaracnóideo de cobaias. MÉTODO: Quarenta cobaias foram divididas em quatro grupos. Anestesiadas com O2 a 100% e isoflurano a 2%, com posterior punção no espaço intervertebral L6-S1. Nos animais do Grupo I foram administrados 2 mL de solução fisiológica a 0,9%; no Grupo II, 2 mL de bupivacaína 0,5%; no Grupo III, 2 mL de bupivacaína S75-R25 0,5% e no Grupo IV, 2 mL de levobupivacaína 0,5%. Após o despertar, nos momentos 0, 60, 120 e 180 minutos, foi realizado exame neurológico, diariamente, por uma semana. Os animais foram sacrificados e submetidos à perfusão com paraformaldeído a 4%. Após a fixação, a medula espinal foi isolada por dissecção e analisada histologicamente para avaliação do grau de lesão medular. RESULTADOS: As cobaias do grupo-controle não apresentaram bloqueio nervoso. As do Grupo II apresentaram bloqueio sensitivo e motor por mais de 180 minutos. Nos Grupos III (S75-R25) e IV (levobupivacaína) houve bloqueios motor e sensitivo no momento 0 minuto; contudo, no momento 60 minutos o bloqueio motor era mínimo. Ao exame histológico, o Grupo I não apresentou alterações. No Grupo II foram encontradas alterações medulares intensas. Nos Grupos III e IV as alterações medulares foram pouco intensas. CONCLUSÕES: A levobupivacaína em grandes volumes causou pouco dano ao sistema nervoso, comparada com a bupivacaína. Entre levobupivacaína e bupivacaína S75-R25, não houve diferença estatística significativa.

Palavras-chave

ANESTÉSICOS, Local, ANESTÉSICOS, Local, ANESTÉSICOS, Local, ANIMAL, COMPLICAÇÕES, COMPLICAÇÕES, TÉCNICAS ANESTÉSICAS, Regional

Abstract

BACKGROUND AND OBJECTIVES: Levobupivacaine has less central nervous system side effects than racemic bupivacaine, but its anesthetic effect is not as intense. The objective of this experimental study was to compare the adverse effects of large volumes of bupivacaine, S75-R25 bupivacaine, and levobupivacaine injected in the subarachnoid space of guinea pigs. METHODS: Forty guinea pigs were divided in four groups. They were anesthetized with 100% O2 and 2% isoflurane, followed by puncture of the L6-S1 intervertebral space. In Group I, 2 mL of normal saline were injected; in Group II, 2 mL of 0.5% bupivacaine; in Group III, 2 mL of 0.5% S75-R25 bupivacaine, and in Group IV, 2 mL of 0.5% levobupivacaine. After the animal awakened, neurological exam was done at 0, 60, 120, and 180 minutes, and daily for one week. Animals were killed and underwent perfusion with 4% paraformaldehyde. After fixation, the spinal cord was isolated by dissection and analyzed histologically to evaluate the degree of spinal cord lesions. RESULTS: Guinea pigs in the control group did not present nervous block. Those in Group II presented sensitive and motor block for more than 180 minutes. Animals in Groups III (S75-R25) and IV (levobupivacaine) developed sensitive and motor blockade at moment 0, but at 60 minutes the motor blockade was minimal. Histologic exam in Group I showed no changes. In Group II, severe spinal cord changes were observed. In Groups III and IV, spinal cord changes were mild. CONCLUSIONS: Large volumes of levobupivacaine caused little damage in the central nervous system when compared with bupivacaine. Statistically significant changes were not observed between levobupivacaine and S75-R25 bupivacaine.

Keywords

ANESTHETICS, Local, ANESTHETICS, Local, ANESTHETICS, Local, ANESTHETIC TECHNIQUE, Regional, ANIMAL, COMPLICATIONS, COMPLICATIONS

References

Tetzlaff JE. The pharmacology of local anesthetics. Anesthesiol Clin North Am. 2000;18:217-233.

Ritchie JM, Greene NM. Local Anesthetics. The Pharmacological Basis of Therapeutics. 1990:311-329.

Stoelting RK. Anestésicos Locais. Manual de Farmacologia e Fisiologia na Prática Anestésica. 1997:100-114.

Stoelting RK. Anestésicos Locais. Manual de Anestesiologia Clínica. 1991:223-242.

Strichrtz GR, Cocino BG. Local Anesthetics. Anesthesia. 1990:437-465.

McClellan KJ, Spencer CM. Levobupivacaine. Drugs. 1998;56:355-362.

Foster RH, Markham A. Levobupivacaine: a review of its pharmacology and use as a local anaesthetic. Drugs. 2000;59:551-579.

Simonetti MPB, Valinetti EA, Ferreira FMC. Avaliação da atividade anestésica local da S(-) bupivacaína: estudo experimental in vivo no nervo ciático de rato. Rev Bras Anestesiol. 1997;47:425-434.

Kopacz DJ, Allen H, Thompson G. A comparison of epidural levobupivacaine 0.75% with racemic bupivacaine for lower abdominal surgery. Anesth Analg. 2000;90:642-648.

Vladimirov M, Nau C, Mok WM. Potency of bupivacaine stereoisomers tested in vitro and in vivo. Anesthesiology. 2000;93:744-755.

Simonetti MPB, Ferreira FMC. Does the D-isomer of bupivacaine contribute to the improvement of efficacy in neural block?. Reg Anaesth Pain Med. 1999;24(^ssuppl):43.

Simonetti MPB, Bird RA. Evaluation of new local anesthetics obtained through the manipulation of the enantiomeric ratio of bupivacaine on the central nervous system of the rat. Int Monitor. 2000;12:129.

Delfino J, Vale NB. Bupivacaína levógira a 0,5% pura versus mistura enantiomérica de bupivacaína (S75-R25) a 0,5% em anestesia peridural para cirurgia de varizes. Rev Bras Anestesiol. 2001;51:474-482.

Ben-David B, Rawa R. Complications of neuraxial blockade. Anesthesiol Clin North Am. 2002;20:669-693.

Munnur U, Suresh MS. Backache, headache, and neurologic deficit after regional anesthesia. Anesthesiol Clin North Am. 2003;21:71-86.

Beardsley D, Holman S, Gantt R. Transient neurological deficit after spinal anesthesia: local anesthetic maldistribution with pencil point needles?. Anesth Analg. 1995;81:314-320.

Lambert DH, Hurley RJ. Cauda equina syndrome and continuous spinal anesthesia. Anesth Analg. 1991;72:817-819.

Drasner K, Rigler M, Sessler DI. Cauda equina syndrome following intended epidural anesthesia. Anesthesiology. 1992;77:582-585.

Capelozzi M, Arantes FM, Paiva PSO. Spinal anesthesia increases pulmonary responsiveness to methacholine in guinea pigs. Anesth Analg. 1998;87:874-878.

Ready LB, Plumer MH, Haschke RH. Neurotoxicity of intrathecal local anesthetics in rabbits. Anesthesiology. 1985;63:364-70.

Bahar M, Rosen M, Vickers MDV. Chronic cannulation of the intradural or extradural space in the rat. Br J Anaesth. 1984;56:405-10.

Durant PAC, Yaksh TL. Epidural injections of bupivacaine, morphine, fentanil, lofentanil, and DADL in chronically implanted rats: A pharmacologic and pathologic study. Anesthesiology. 1986;64:43-53.

Kannai Y, Tateyama S, Nakamura T. Effects of levobupivacaine, bupivacaine and ropivacaine on tail-flick and motor function in rats following epidural or intrathecal administration. Reg Anesth Pain Med. 1999;24:444-452.

Cooper G, Schiller A. Guinea Pig Anatomy. 1980:152-153.

Ganem EM, Vianna PTG, Marques M. Efeitos da administração subaracnóidea de grandes volumes lidocaína a 2% e ropivacaína a 1% sobre a medula espinal e as meninges: Estudo experimental em cães. Rev Bras Anestesiol. 2003;53:351-360.

Myers RR, Sommer C. Methodology for spinal neurotoxicity studies. Reg Anesth. 1993;18:439-447.

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