Concentração eficaz mínima de bupivacaína em bloqueio do nervo femoral guiado por ultrassom após meniscectomia artroscópica de joelho: estudo randomizado, duplo-mascarado
Data
2015-03-31
Autores
Moura, Ed Carlos Rey 
Orientadores
Sakata, Rioko Kimiko
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Objetivos: Um dos requisitos para alta hospitalar é a analgesia adequada. O bloqueio do nervo periférico pode reduzir a necessidade de analgésicos sistêmicos; entretanto, pode ocorrer bloqueio motor, dependendo da concentração do anestésico local utilizado. Guiado por ultrassom, a concentração de anestésico local pode ser reduzido. O objetivo primário deste estudo foi obter a concentração analgésica eficaz mínima da bupivacaína no bloqueio femoral guiado por ultrassom para meniscectomia artroscópica de joelho. Métodos: Este estudo foi prospectivo, randomizado, duplo-cego. Um total de 52 pacientes foram submetidos a meniscectomia artroscópica do joelho e receberam bloqueio femoral guiada por ultrassom usando 22 ml de bupivacaína. A concentração de bupivacaína dada a um paciente foi determinada pela resposta do paciente anterior (a biased-coin design up?down sequential method). Se teve uma resposta negativa, a concentração de bupivacaína foi aumentada em 0,05% no próximo paciente. Se teve uma resposta positiva, o próximo paciente foi randomizado para receber a mesma concentração de bupivacaína (com uma probabilidade de 0,89) ou para receber uma concentração de 0,05% menor (com uma probabilidade de 0,11). Sucesso de bloqueio foi definida como dor <4 na escala numérica da intensidade da dor (0 = sem dor e 10 = pior dor imaginável) em três diferentes tempos de avaliação. Se dor > ou igual 4 o bloqueio foi caracterizado como um fracasso, porque provavelmente precisaria de drogas analgésicas mais potentes (opióides) e retardaria a alta precose do paciente, saindo do foco primário do estudo. Foram submetidos a anestesia geral com alfentanil 30 ug/Kg, propofol 2mg/Kg, manutenção com propofol, havendo necessidade poderia receber remifentanil. A complementação da analgesia pós-operatória foi com dipirona e se necessário, cetoprofeno e tramadol (50mg). Foram avaliados: intensidade de dor, duração da analgesia, dose de analgésico complementar e consumo de remifentanil. Resultados:. A CEM50 foi de 0,160% (IC 95%: 0,150-0,189) e a CEM90 foi de 0,271% (IC 95% : 0,196-0,300). O tempo para solicitação da primeira dose de analgésico foi de 463 ± 245,9 min, sendo que em concentrações superiores a 0,3% foi de 604,3 ± 255,2 min. Conclusões: A CEM da bupivacaína para analgesia em bloqueio femoral guiado por ultrassom em 50% dos pacientes foi de 0,160%, e em 90% dos pacientes, foi de 0,271%.
Objectives: One of the requirements for hospital discharge after meniscectomy is adequate analgesia. A femoral nerve block may reduce the need for systemic analgesics, however, motor block can occur. Guided by ultrasound can reduce the local anesthetic concentration required. The primary objective of this study was to obtain the lowest effective analgesic concentration (EC50 and EC90) of bupivacaine in ultrasound-guided femoral nerve block for arthroscopic knee meniscectomy. Methods: This was a randomized, double-blind study, and patients were distributed into groups using the "up-and-down" method. The first patient received 22 ml of 0.25% bupivacaine; upon negative response, the concentration of bupivacaine was increased by 0.05% in the next patient; upon positive response, the next patient randomly received either the same concentration or a 0.05% lower concentration. A total of 52 patients undergoing arthroscopic knee meniscectomy were evaluated. The patients received 0.01 mg/kg midazolam by IV 5 min before the block. They underwent general anesthesia with 30 mcg/kg alfentanil, 2 mg/kg propofol, and maintenance with propofol, and they received remifentanil if needed. Postoperative analgesia supplementation was performed with dipyrone and, if necessary, ketoprofen; tramadol was used (50 mg) if no relief was achieved. There was evaluated: bupivacain CEM 50 and CEM 90, pain intensity, duration of analgesia, supplementary analgesic dose during 24 hours, and remifentanil administration during surgery. Results: The minimum effective concentration in 50% of patients (MEC50) was 0.160 (95% CI: 0.150-0.189), and MEC90 was 0.271 (95% CI: 0.196-0.300). There was no difference in pain intensity for different concentrations of bupivacaine. Block success occurred in 45 patients, with no difference among bupivacaine concentrations. The length of time until request of the first analgesic dose was higher with bupivacaine concentration ? 0.3% (543.8 ± 283.8 min) than with 0.25% (391.3 ± 177.8 min) or < 0.25% (302.3 ± 210.1 min). Conclusions: The MEC50 of bupivacaine for analgesia in administering an ultrasound-guided femoral nerve block was 0.160 (95% CI: 0.150-0.189), and the MEC90 was 0.271 (95% CI: 0.196-0.300).
Objectives: One of the requirements for hospital discharge after meniscectomy is adequate analgesia. A femoral nerve block may reduce the need for systemic analgesics, however, motor block can occur. Guided by ultrasound can reduce the local anesthetic concentration required. The primary objective of this study was to obtain the lowest effective analgesic concentration (EC50 and EC90) of bupivacaine in ultrasound-guided femoral nerve block for arthroscopic knee meniscectomy. Methods: This was a randomized, double-blind study, and patients were distributed into groups using the "up-and-down" method. The first patient received 22 ml of 0.25% bupivacaine; upon negative response, the concentration of bupivacaine was increased by 0.05% in the next patient; upon positive response, the next patient randomly received either the same concentration or a 0.05% lower concentration. A total of 52 patients undergoing arthroscopic knee meniscectomy were evaluated. The patients received 0.01 mg/kg midazolam by IV 5 min before the block. They underwent general anesthesia with 30 mcg/kg alfentanil, 2 mg/kg propofol, and maintenance with propofol, and they received remifentanil if needed. Postoperative analgesia supplementation was performed with dipyrone and, if necessary, ketoprofen; tramadol was used (50 mg) if no relief was achieved. There was evaluated: bupivacain CEM 50 and CEM 90, pain intensity, duration of analgesia, supplementary analgesic dose during 24 hours, and remifentanil administration during surgery. Results: The minimum effective concentration in 50% of patients (MEC50) was 0.160 (95% CI: 0.150-0.189), and MEC90 was 0.271 (95% CI: 0.196-0.300). There was no difference in pain intensity for different concentrations of bupivacaine. Block success occurred in 45 patients, with no difference among bupivacaine concentrations. The length of time until request of the first analgesic dose was higher with bupivacaine concentration ? 0.3% (543.8 ± 283.8 min) than with 0.25% (391.3 ± 177.8 min) or < 0.25% (302.3 ± 210.1 min). Conclusions: The MEC50 of bupivacaine for analgesia in administering an ultrasound-guided femoral nerve block was 0.160 (95% CI: 0.150-0.189), and the MEC90 was 0.271 (95% CI: 0.196-0.300).
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Citação
MOURA, Ed Carlos Rey. Concentração eficaz mínima de bupivacaína em bloqueio do nervo femoral guiado por ultrassom após meniscectomia artroscópica de joelho: estudo randomizado, duplo-mascarado. 2015. 53 f. Dissertação (Mestrado em Ciência Cirúrgica Interdisciplinar) - Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), São Paulo, 2015.