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1.
Acta cir. bras ; 30(12): 831-837, Dec. 2015. tab, graf
Artigo em Inglês | LILACS | ID: lil-769499

RESUMO

ABSTRACT PURPOSE : To investigate the analgesic effect of acupuncture (AP) or micro-dose pharmacopuncture (PA), using carprofen or morphine, in bitches undergoing ovariohysterectomy (OHE). METHODS: Thirty five dogs were randomly assigned to five groups after sedation with acepromazine IM: AP, 0.5 mg.kg-1 of morphine subcutaneously (SC), 4 mg.kg-1 of carprofen SC, and PA with 0.05 mg.kg-1 of morphine or 0.4 mg.kg-1 of carprofen. Anaesthesia was induced with propofol and maintained with isoflurane. Pain was assessed after OHE by a blind observer for 24h, by dynamic visual analogue scale (DIVAS), Glasgow (CMPS-SF), Melbourne (UMPS) and Colorado University pain scale (CSU). Animals reaching 33% of the UMPS score received rescue analgesia with morphine IM. Non parametric data were analysed by Kruskal-Wallis or Friedman tests where applicable, followed by Dunn´s test. Parametric data were analysed by two way ANOVA, followed by Tukey test. RESULTS: There were no differences among groups in number of rescue analgesia. Except for the DIVAS score where animals treated with morphine had the lowest score compared with AP and carprofen, at 1h after surgery, there were no other differences among groups. CONCLUSION: Acupuncture or pharmacopuncture were equally effective as morphine or carprofen to control postoperative pain in bitches undergoing ovariohysterectomy.


Assuntos
Animais , Cães , Feminino , Analgesia por Acupuntura/veterinária , Analgésicos Opioides/uso terapêutico , Carbazóis/uso terapêutico , Histerectomia/veterinária , Morfina/uso terapêutico , Ovariectomia/veterinária , Dor Pós-Operatória/veterinária , Pontos de Acupuntura , Analgesia por Acupuntura/métodos , Anti-Inflamatórios não Esteroides/uso terapêutico , Histerectomia/efeitos adversos , Ovariectomia/efeitos adversos , Estudos Prospectivos , Medição da Dor/veterinária , Dor Pós-Operatória/terapia
2.
Acta Cir Bras ; 30(12): 831-7, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26735055

RESUMO

PURPOSE: To investigate the analgesic effect of acupuncture (AP) or micro-dose pharmacopuncture (PA), using carprofen or morphine, in bitches undergoing ovariohysterectomy (OHE). METHODS: Thirty five dogs were randomly assigned to five groups after sedation with acepromazine IM: AP, 0.5 mg.kg(-1) of morphine subcutaneously (SC), 4 mg.kg(-1) of carprofen SC, and PA with 0.05 mg.kg(-1) of morphine or 0.4 mg.kg(-1) of carprofen. Anaesthesia was induced with propofol and maintained with isoflurane. Pain was assessed after OHE by a blind observer for 24h, by dynamic visual analogue scale (DIVAS), Glasgow (CMPS-SF), Melbourne (UMPS) and Colorado University pain scale (CSU). Animals reaching 33% of the UMPS score received rescue analgesia with morphine IM. Non parametric data were analysed by Kruskal-Wallis or Friedman tests where applicable, followed by Dunn's test. Parametric data were analysed by two way ANOVA, followed by Tukey test. RESULTS: There were no differences among groups in number of rescue analgesia. Except for the DIVAS score where animals treated with morphine had the lowest score compared with AP and carprofen, at 1h after surgery, there were no other differences among groups. CONCLUSION: Acupuncture or pharmacopuncture were equally effective as morphine or carprofen to control postoperative pain in bitches undergoing ovariohysterectomy.


Assuntos
Analgesia por Acupuntura/veterinária , Analgésicos Opioides/uso terapêutico , Carbazóis/uso terapêutico , Histerectomia/veterinária , Morfina/uso terapêutico , Ovariectomia/veterinária , Dor Pós-Operatória/veterinária , Analgesia por Acupuntura/métodos , Pontos de Acupuntura , Animais , Anti-Inflamatórios não Esteroides/uso terapêutico , Cães , Feminino , Histerectomia/efeitos adversos , Ovariectomia/efeitos adversos , Medição da Dor/veterinária , Dor Pós-Operatória/terapia , Estudos Prospectivos
3.
Vet Anaesth Analg ; 38(3): 252-9, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21492391

RESUMO

OBJECTIVE: To compare the post-operative analgesic effects of butorphanol or firocoxib in dogs undergoing ovariohysterectomy. STUDY DESIGN: Prospective, randomized, blinded, clinical trial. ANIMALS: Twenty-five dogs >1 year of age. METHODS: Dogs received acepromazine intramuscularly (IM), 0.05 mg kg(-1) and either butorphanol IM, 0.2 mg kg(-1) (BG, n = 12) or firocoxib orally (PO), 5 mg kg(-1) (FG, n = 13), approximately 30 minutes before induction of anesthesia with propofol. Anesthesia was maintained with isoflurane. Ovariohysterectomy was performed by the same surgeon. Pain scores using the dynamic and interactive visual analog scale (DIVAS) were performed before and at 1, 2, 3, 4, 6, 8 and 20 hours after the end of surgery by one observer, blinded to the treatment. Rescue analgesia was provided with morphine (0.5 mg kg(-1)) IM and firocoxib, 5 mg kg(-1) (BG only) PO if DIVAS >50. Groups were compared using paired t-tests and Fisher's exact test (p < 0.05). Data are presented as mean ± SD. RESULTS: The BG required significantly less propofol (BG: 2.6 ± 0.59 mg kg(-1); FG: 5.39 ± 0.7 mg kg(-1)) (p < 0.05) but the anesthesia time was longer (BG: 14 ± 6, FG: 10 ± 4 minutes). There were no differences for body weight (BG: 7.9 ± 5.0, FG: 11.5 ± 4.6 kg), sedation scores, and surgery and extubation times (BG: 10 ± 2, 8 ± 5 minutes; FG: 9 ± 3, 8 ± 4 minutes, respectively) (p > 0.05). The FG had significantly lower pain scores than the BG at 1, 2 and 3 hours following surgery (p < 0.05). Rescue analgesia was administered to 11/12 (92%) and 2/13 (15%) dogs in the BG and FG, respectively (p < 0.05). CONCLUSION AND CLINICAL RELEVANCE: Firocoxib produced better post-operative analgesia than butorphanol. Firocoxib may be used as part of a multimodal analgesia protocol but may not be effective as a sole analgesic.


Assuntos
4-Butirolactona/análogos & derivados , Analgésicos Opioides/uso terapêutico , Butorfanol/uso terapêutico , Cães/cirurgia , Histerectomia/veterinária , Ovariectomia/veterinária , Dor Pós-Operatória/veterinária , Sulfonas/uso terapêutico , 4-Butirolactona/uso terapêutico , Animais , Feminino , Medição da Dor/veterinária , Dor Pós-Operatória/tratamento farmacológico , Método Simples-Cego
4.
J. vasc. bras ; 7(3): 231-238, set. 2008. ilus, graf
Artigo em Português | LILACS | ID: lil-500241

RESUMO

CONTEXTO: A cirurgia videolaparoscópica (CVL) vem evoluindo como alternativa cirúrgica menos invasiva para o tratamento da doença aterosclerótica oclusiva aorto-ilíaca e do aneurisma da aorta abdominal. Poucos estudos avaliaram objetivamente a curva de aprendizado com essa técnica em cirurgia vascular. OBJETIVO: Avaliar objetivamente os tempos e a evolução de cada passo cirúrgico e demonstrar a exeqüibilidade dessa técnica. MÉTODOS: Entre outubro 2007 e janeiro de 2008, dois cirurgiões vasculares iniciantes na CVL operaram, após cursos e treinamentos, seis porcos consecutivos, com dissecção aórtica e interposição de um enxerto de dácron em um segmento da aorta infra-renal abdominal, com técnica totalmente laparoscópica. RESULTADOS: Todos os tempos cirúrgicos foram decrescentes ao longo do estudo, apresentando redução de 45,9% no tempo total de cirurgia, 85,8% no tempo de dissecção da aorta, 81,2% na exposição da aorta, 55,1% no clampeamento total, 71% na confecção da anastomose proximal e 64,9% na anastomose distal. CONCLUSÃO: O presente estudo mostrou que os resultados técnicos satisfatórios da CVL vascular ocorreram somente após longa curva de aprendizado, que foi decrescente ao longo do tempo, à medida que aumentou a experiência e vivência com os materiais e com a visão não-estereoscópica. Essa técnica pode ser realizada com perfeição por cirurgiões vasculares desde que façam cursos especializados, com treinamento em simuladores e animais, e desde que busquem constante aprimoramento a fim de conseguir resultados similares aos obtidos com a cirurgia convencional.


BACKGROUND: Laparoscopic aortic surgery (LAS) is evolving as a minimal invasive alternative technique for the treatment of abdominal aortic aneurysms and peripheral aortoiliac arterial disease. Few articles have objectively evaluated the technique learning curve in vascular surgery. OBJECTIVE: The aim of the present experimental study was to demonstrate surgical feasibility and evaluate each surgical step of LAS. METHODS: Between October 2007 and January 2008, two beginning surgeons attended laparoscopic courses and operated on six consecutive pigs with a total laparoscopic retroperitoneal aortic dissection and interposition of a Dacron tube graft in the infrarenal aortic segment. Both anastomoses were performed under total laparoscopic technique. RESULTS: All surgical time curves decreased along time: 45.9% in total surgical time, 85.8% in dissection time, 81.2% in aortic exposure, 55.1% in total cross-clamping, 71% in proximal anastomosis and 64.9% in distal anastomosis. CONCLUSION:This experimental study showed that satisfactory results with LAS were only reached after a long learning curve. However, this learning curve decreased along time, as experience with the technique, materials and non-stereoscopic vision improved. Vascular surgeons should attend practical courses and should have training opportunities in simulators and animals to achieve results similar to those of conventional surgery.


Assuntos
Animais , Cobaias , Anastomose Cirúrgica , Aorta/cirurgia , Doenças Vasculares/cirurgia , Doenças Vasculares/veterinária
5.
Acta Cir Bras ; 23(1): 55-64, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18278394

RESUMO

PURPOSE: To compare the hemodynamic repercussions following a toxic dose of levobupivacaine and bupivacaine intravascularly injected in swines. METHODS: Large White pigs were anesthetized with thiopental, tracheal intubation was performed and mechanical ventilation was instituted. Hemodynamic variables were recorded with invasive pressure monitoring and pulmonary artery catheterization (Swan-Ganz catheter). After a 30-minute resting period, the animals were randomly divided into two groups in a double-blinded fashion and received a bolus injection of 4 mg/kg of either agent for intoxication. Hemodynamic results were then evaluated at 1, 5, 10, 15, 20 and 30 minutes. RESULTS: Levobupivacaine had greater hemodynamic repercussions than racemic bupivacaine. These results disagree with those found when the levorotatory isomer of bupivacaine was used in humans, but are in agreement with recently reported findings in animals. CONCLUSION: Levobupivacaine was shown to be more toxic in pigs than racemic bupivacaine when large doses are injected intravenously.


Assuntos
Anestésicos Locais/toxicidade , Bupivacaína/toxicidade , Cardiopatias/induzido quimicamente , Hemodinâmica/efeitos dos fármacos , Animais , Bupivacaína/análogos & derivados , Sistema Cardiovascular/efeitos dos fármacos , Pressão Venosa Central/efeitos dos fármacos , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Feminino , Humanos , Levobupivacaína , Masculino , Distribuição Aleatória , Suínos , Resistência Vascular/efeitos dos fármacos
6.
Acta cir. bras ; 23(1): 55-64, Jan.-Feb. 2008. ilus, tab
Artigo em Inglês | LILACS | ID: lil-474141

RESUMO

PURPOSE: To compare the hemodynamic repercussions following a toxic dose of levobupivacaine and bupivacaine intravascularly injected in swines. Methods: Large White pigs were anesthetized with thiopental, tracheal intubation was performed and mechanical ventilation was instituted. Hemodynamic variables were recorded with invasive pressure monitoring and pulmonary artery catheterization (Swan-Ganz catheter). After a 30-minute resting period, the animals were randomly divided into two groups in a double-blinded fashion and received a bolus injection of 4 mg/kg of either agent for intoxication. Hemodynamic results were then evaluated at 1, 5, 10, 15, 20 and 30 minutes. RESULTS: Levobupivacaine had greater hemodynamic repercussions than racemic bupivacaine. These results disagree with those found when the levorotatory isomer of bupivacaine was used in humans, but are in agreement with recently reported findings in animals. CONCLUSION: Levobupivacaine was shown to be more toxic in pigs than racemic bupivacaine when large doses are injected intravenously.


OBJETIVO: Comparar as repercussões hemodinâmicas da levobupivacaína e bupivacaína após uma dose tóxica intravascular em suínos. MÉTODOS: Porcos Large-White foram anestesiados com tiopental, entubados e mantidos em ventilação controlada mecânica. Parâmetros hemodinâmicos foram registrados através de pressão invasiva e cateterização da artéria pulmonar (cateter de Swan-Ganz). Após 30 minutos de repouso, os animais foram divididos aleatoriamente em dois grupos e receberam injeção endovenosa em duplo-cego de 4 mg/kg de um ou outro agente anestésico simulando uma intoxicação. Foram avaliados resultados hemodinâmicos aos 1, 5, 10, 15, 20 e 30 minutos. RESULTADOS: Levobupivacaína teve maiores repercussões hemodinâmicas que a bupivacaína racêmica. Estes resultados discordam daqueles encontrados com o isômero levógiro em humanos, mas estão de acordo com resultados recentemente informados em animais. CONCLUSÃO: Levobupivacaína mostrou ser agente mais tóxico em suínos do que a bupivacaína racêmica quando grandes doses são injetadas por via intravascular.


Assuntos
Animais , Feminino , Humanos , Masculino , Anestésicos Locais/toxicidade , Bupivacaína/toxicidade , Cardiopatias/induzido quimicamente , Hemodinâmica/efeitos dos fármacos , Bupivacaína/análogos & derivados , Sistema Cardiovascular/efeitos dos fármacos , Pressão Venosa Central/efeitos dos fármacos , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Distribuição Aleatória , Suínos , Resistência Vascular/efeitos dos fármacos
7.
Rev Assoc Med Bras (1992) ; 53(6): 502-5, 2007.
Artigo em Português | MEDLINE | ID: mdl-18157363

RESUMO

BACKGROUND: Racemic bupivacaine has been the local anaesthetic of choice in regional blocks due to quality and duration of anesthesia. However its cardiovascular toxicity has been a source of concern and research has been made for lesser impact drugs. One choice is its levogyre isomer, levobupivacaine, apparently less cardiotoxic due a lower affinity to the heart sodium channels. In Brazil, a drug containing 75% of levogyre isomer and 25% of dextrogyre isomer, called enantiomeric excess mixture, is available. This study intends to evaluate haemodynamic effects of the intravascular injection of a toxic dose of both agents in swine. METHODS: Large White pigs were anaesthetized with thiopental, intubated and placed on mechanical ventilation. Haemodynamic monitoring was performed with an invasive blood pressure and Swan-Ganz catheter on a pulmonary artery. After a 30 minute rest period, animals were randomly divided in two groups and the intoxication was performed on a double-blind method with 4 mg.kg-1 of one of the drugs. Haemodynamic parameters were then evaluated at 1, 5, 10, 15, 20 and 30 minutes. RESULTS: The enantiomeric excess mixture caused greater haemodynamic effects than the racemic bupivacaine. These results diverge from those found in humans with levogyre isomer but are similar to recent results reported in animals. Care should be taken when extrapolating data obtained in swine to humans and further research is necessary. CONCLUSION: When high doses are injected in swine, the enantiomeric excess mixture was more toxic than the racemic bupivacaine.


Assuntos
Anestésicos Locais/toxicidade , Bupivacaína/toxicidade , Sistema Cardiovascular/efeitos dos fármacos , Hemodinâmica/efeitos dos fármacos , Anestesia Intravenosa , Anestésicos Locais/química , Animais , Bupivacaína/química , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Feminino , Masculino , Estereoisomerismo , Suínos
8.
Rev. bras. anestesiol ; 57(1): 63-73, jan.-fev. 2007. graf
Artigo em Português | LILACS | ID: lil-440118

RESUMO

JUSTIFICATIVA E OBJETIVOS: Até recentemente, a bupivacaína tem sido o anestésico de escolha nos bloqueios locorregionais em razão da qualidade da anestesia proporcionada e pela sua duração. Apesar disso, sua toxicidade cardiovascular preocupa os anestesiologistas que procuram novas opções farmacológicas com menor grau desse inconveniente. Uma destas é o seu isômero levógiro, a levobupivacaína, que por uma menor afinidade aos receptores dos canais de sódio da célula cardíaca, seria menos cardiotóxica. Em nosso meio está disponível a apresentação contendo 75 por cento do isômero levógiro e 25 por cento do isômero dextrógiro, denominada mistura com excesso enantiomérico de 50 por cento. O objetivo deste estudo foi avaliar as repercussões hemodinâmicas da injeção intravascular de dose tóxica desses três agentes, buscando encontrar qual deles tem menor impacto em caso de acidente. MÉTODO: Suínos da raça Large White foram anestesiados com tiopental, intubados e ventilados mecanicamente, sendo em seguida instalada monitorização hemodinâmica com cateter de Swan-Ganz e pressão invasiva para estudo das variáveis hemodinâmicas. Após repouso, foram divididos de forma aleatória em três grupos e realizada intoxicação duplamente encoberta com um dos agentes na dose de 4 mg.kg-1. Os resultados hemodinâmicos foram avaliados durante 30 minutos. Aos resultados foram aplicados testes estatísticos para comparação entre os grupos. RESULTADOS: A mistura com excesso enantiomérico de 50 por cento e a levobupivacaína causaram maiores repercussões hemodinâmicas do que a mistura racêmica, sendo estas mais pronunciadas com o primeiro agente. Esses resultados se opõem aos encontrados em humanos, sobretudo quando da utilização do isômero levógiro puro, mas estão de acordo com resultados recentes também em animais. Extrapolar dados obtidos em suínos para seres humanos exige muita cautela e novos estudos são necessários. CONCLUSÕES: Em suínos, a mistura com excesso...


BACKGROUND AND METHODS: Until recently, bupivacaine had been the anesthetic of choice for loco-regional blocks due to the quality and duration of the anesthesia. But its cardiovascular toxicity is a source of concern for anesthesiologists who seek new pharmacological options with a smaller degree of this problem. Its levorotatory isomer, levobupivacaine, that would be less cardiotoxic due a smaller affinity for the receptors of the sodium channels of the cardiac cell, is one of these options. In Brazil, a presentation containing 75 percent of the levorotatory isomer and 25 percent of the dextrorotatory isomer, called 50 percent enantiomeric excess mixture is available. The aim of this study was to evaluate the hemodynamic repercussions of the intravascular injection of a toxic dose of those three agents to determine which one has the least impact in the case of an accident. METHODS: Large White pigs were anesthetized with thiopental, intubated, and placed on mechanical ventilation. Hemodynamic monitoring was achieved with a Swan-Ganz catheter and invasive blood pressure. After a period of rest, the animals were randomly divided in three groups. The intoxication was performed, on a double-blind fashion, with 4 mg.kg-1 of one of the drugs. Hemodynamic parameters were evaluated during 30 minutes. Analytical tests were used to compare the results among the groups. RESULTS: The 50 percent enantiomeric excess mixture and levobupivacaine had greater hemodynamic repercussions than the racemic mixture, which were more pronounced with the first drug. These results go against those found in humans, especially regarding the pure levorotatory isomer, but are similar to recent results reported in animals. One should be careful when extrapolating the data obtained in pigs to humans and further studies are necessary. CONCLUSIONS: In pigs, the 50 percent enantiomeric excess mixture, in particular, and levobupivacaine were more toxic when administered...


JUSTIFICATIVA Y OBJETIVOS: La bupivacaína ha sido hasta hace poco tiempo el anestésico por elección en los bloqueos loco-regionales en razón de la calidad de la anestesia proporcionada y por su duración. A pesar de eso, su toxicidad cardiovascular preocupa a los anestesiólogos que buscan nuevas opciones farmacológicas con un menor grado de ese inconveniente. Una de ellas es su isómero levógiro, la levobupivacaína, que por una menor afinidad con los receptores de los canales de sodio de la célula cardiaca, sería menos cardiotóxica. En nuestro medio está disponible la presentación que contiene un 75 por ciento del isómero levógiro y un 25 por ciento del isómero dextrógiro, denominada mezcla con exceso enantiomérico de 50 por ciento. El objetivo de este estudio fue el de evaluar las repercusiones hemodinámicas de la inyección intravascular de dosis tóxica de esos tres agentes, buscando encontrar cuál de ellos registra un menor impacto en caso de accidente. MÉTODO: Cerdos de la raza Large White fueron anestesiados con tiopental, intubados y ventilados mecánicamente, siendo a continuación instalada la monitorización hemodinámica con catéter de Swan-Ganz y presión invasiva para estudio de las variables hemodinámicas. Después del reposo, fueron divididos aleatoriamente en tres grupos y realizada intoxicación doble encubierta con uno de los agentes en dosis de 4 mg.kg-1. Los resultados hemodinámicos fueron evaluados durante 30 minutos. A los resultados se les aplicó pruebas estadísticas para la comparación entre los grupos. RESULTADOS: La mezcla con exceso enantiomérico de 50 por ciento y la levobupivacaína causaron mayores repercusiones hemodinámicas que la mezcla racémica, siendo esas más fuertes con el primer agente. Esos resultados se oponen a los ya encontrados en humanos, particularmente cuando se utiliza el isómero levógiro puro, pero están a tono con los resultados recientes también obtenidos en animales. Rebasar los datos obtenidos...


Assuntos
Animais , Bupivacaína/toxicidade , Hemodinâmica , Suínos
9.
Rev Bras Anestesiol ; 57(1): 63-73, 2007 Feb.
Artigo em Inglês, Português | MEDLINE | ID: mdl-19468619

RESUMO

BACKGROUND AND METHODS: Until recently, bupivacaine had been the anesthetic of choice for loco-regional blocks due to the quality and duration of the anesthesia. But its cardiovascular toxicity is a source of concern for anesthesiologists who seek new pharmacological options with a smaller degree of this problem. Its levorotatory isomer, levobupivacaine, that would be less cardiotoxic due a smaller affinity for the receptors of the sodium channels of the cardiac cell, is one of these options. In Brazil, a presentation containing 75% of the levorotatory isomer and 25% of the dextrorotatory isomer, called 50% enantiomeric excess mixture is available. The aim of this study was to evaluate the hemodynamic repercussions of the intravascular injection of a toxic dose of those three agents to determine which one has the least impact in the case of an accident. METHODS: Large White pigs were anesthetized with thiopental, intubated, and placed on mechanical ventilation. Hemodynamic monitoring was achieved with a Swan-Ganz catheter and invasive blood pressure. After a period of rest, the animals were randomly divided in three groups. The intoxication was performed, on a double-blind fashion, with 4 mg kg(-1) of one of the drugs. Hemodynamic parameters were evaluated during 30 minutes. Analytical tests were used to compare the results among the groups. RESULTS: The 50% enantiomeric excess mixture and levobupivacaine had greater hemodynamic repercussions than the racemic mixture, which were more pronounced with the first drug. These results go against those found in humans, especially regarding the pure levorotatory isomer, but are similar to recent results reported in animals. One should be careful when extrapolating the data obtained in pigs to humans and further studies are necessary. CONCLUSIONS: In pigs, the 50% enantiomeric excess mixture, in particular, and levobupivacaine were more toxic when administered intravenously than racemic bupivacaine.

10.
Rev. Assoc. Med. Bras. (1992) ; 53(6): 502-505, 2007. graf
Artigo em Português | LILACS | ID: lil-470426

RESUMO

OBJETIVOS: A bupivacaína racêmica tem sido o anestésico local de escolha nos bloqueios regionais pela qualidade e duração de sua anestesia. Sua cardiotoxicidade é motivo de preocupações, e pesquisas têm sido realizadas para encontrar drogas com menor impacto. Seu isômero levógiro, a levobupivacaína, seria menos cardiotóxico pela menor afinidade aos receptores dos canais de sódio do coração, e é uma opção. Em nosso país, uma apresentação contendo 75 por cento do isômero levógiro e 25 por cento do isômero dextrógiro, denominada mistura enantiomérica, está disponível. O objetivo deste estudo foi comparar as repercussões hemodinâmicas da injeção intravascular de uma dose tóxica destes dois agentes em suínos. MÉTODOS: Suínos da raça Large White foram anestesiados com tiopental, entubados e ventilados mecanicamente, sendo, em seguida, instalada monitorização hemodinâmica com pressão invasiva e cateter de Swan-Ganz numa artéria pulmonar. Após repouso de 30 minutos, os animais foram divididos aleatoriamente em dois grupos, e foi realizada em duplo-cego intoxicação com um dos agentes na dose de 4 mg/kg. Os resultados hemodinâmicos foram avaliados então a um minuto, aos cinco, 10, 15, 20 e 30 minutos. RESULTADOS: A mistura enantiomérica causou maiores repercussões hemodinâmicas do que a bupivacaína racêmica. Estes resultados se opõem aos encontrados em humanos com o isômero levógiro, mas estão de acordo com achados recentes em animais. Extrapolar resultados de animais para seres humanos requer cautela, e novas pesquisas são necessárias. CONCLUSÃO: Em suínos, a mistura enantiomérica mostrou-se mais tóxica do que a bupivacaína racêmica, quando grandes doses são injetadas por via endovenosa.


BACKGROUND: Racemic bupivacaine has been the local anaesthetic of choice in regional blocks due to quality and duration of anesthesia. However its cardiovascular toxicity has been a source of concern and research has been made for lesser impact drugs. One choice is its levogyre isomer, levobupivacaine, apparently less cardiotoxic due a lower affinity to the heart sodium channels. In Brazil, a drug containing 75 percent of levogyre isomer and 25 percent of dextrogyre isomer, called enantiomeric excess mixture, is available. This study intends to evaluate haemodynamic effects of the intravascular injection of a toxic dose of both agents in swine. METHODS: Large White pigs were anaesthetized with thiopental, intubated and placed on mechanical ventilation. Haemodynamic monitoring was performed with an invasive blood pressure and Swan-Ganz catheter on a pulmonary artery. After a 30 minute rest period, animals were randomly divided in two groups and the intoxication was performed on a double-blind method with 4 mg.kg-1 of one of the drugs. Haemodynamic parameters were then evaluated at 1, 5, 10, 15, 20 and 30 minutes. RESULTS: The enantiomeric excess mixture caused greater haemodynamic effects than the racemic bupivacaine. These results diverge from those found in humans with levogyre isomer but are similar to recent results reported in animals. Care should be taken when extrapolating data obtained in swine to humans and further research is necessary. CONCLUSION: When high doses are injected in swine, the enantiomeric excess mixture was more toxic than the racemic bupivacaine.


Assuntos
Animais , Feminino , Masculino , Anestésicos Locais/toxicidade , Bupivacaína/toxicidade , Sistema Cardiovascular/efeitos dos fármacos , Hemodinâmica/efeitos dos fármacos , Anestesia Intravenosa , Anestésicos Locais/química , Bupivacaína/química , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Estereoisomerismo , Suínos
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