Brazilian Journal of Anesthesiology
https://bjan-sba.org/article/doi/10.1590/S0034-70942001000500003
Brazilian Journal of Anesthesiology
Scientific Article

Concentração analgésica mínima da bupivacaína durante infusão peridural contínua após bloqueio subaracnóideo no período pós-operatório de cirurgias ortopédicas da perna, tornozelo e pé

Minimum analgesic concentration of bupivacaine after continuous epidural infusion following spinal anesthesia in the postoperative period of leg, ankle and foot surgery

Getúlio Rodrigues de Oliveira Filho; Nilton Gesser; Márcia Regina Ghellar; Ranulfo Goldschmidt; Adilson José Dal Mago

http://dx.doi.org/10.1590/S0034-70942001000500003 Braz J Anesthesiol, vol.51, n5, p.385-393, 2001
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Resumo

JUSTIFICATIVA E OBJETIVOS: A concentração analgésica mínima de um anestésico local (CAM-AL) corresponde à concentração efetiva em 50% das pacientes durante o primeiro estágio do trabalho de parto. Pode ser utilizada para determinar a potência relativa de diferentes agentes e estimar o efeito de drogas analgésicas co-administradas no espaço peridural. O objetivo deste estudo foi o de determinar a CAM-AL da bupivacaína para analgesia peridural de cirurgias ortopédicas. MÉTODO: Foi aplicada a técnica de alocação seqüencial não aleatória duplamente encoberta a 23 adultos submetidos a cirurgias ortopédicas sobre a perna, tornozelo ou pé. A anestesia constou de bloqueio subaracnóideo lombar com bupivacaína hiperbárica. Um cateter peridural colocado em L4-L5 foi avançado 3 a 5 cm em direção cefálica. No período pós-operatório imediato, foram administrados 20 ml de bupivacaína seguida de infusão de 0.15 ml.kg-1.h-1, na concentração apropriada. Escores analógicos visuais de dor e de Bromage foram registrados após 4, 8 e 12 horas. A concentração foi considerada eficaz quando os escores de dor foram inferiores a 10 mm em todas as avaliações. A concentração inicial foi de 0,3% e diminuiu ou aumentou 0,1% caso a resposta do paciente anterior tenha sido ineficaz ou eficaz, respectivamente. A CAM-AL foi calculada pela fórmula de Massey e Dixon. RESULTADOS: A CAM-AL da bupivacaína (limites de 95% de confiança) foi de 0,16% (0,11% e 0,21%). Bloqueio motor intenso foi observado na maioria dos pacientes. CONCLUSÕES: Para uma taxa de infusão de 0.15 ml.kg-1.h-1, a CAM-AL da bupivacaína foi de 0,16%. No entanto, o modelo utilizado pode não ter sido adequado para a avaliação dos efeitos motores das concentrações testadas.

Palavras-chave

ANALGESIA, ANESTÉSICOS, Local, TÉCNICAS ANESTÉSICAS, Regional, TÉCNICAS ANESTÉSICAS, Regional

Abstract

BACKGROUND AND OBJECTIVES: Minimum analgesic concentration of a local anesthetic (MAC-LA) is the effective concentration for 50% of patients (EC50) during the first stage of labor. It may be used to determine relative analgesic potency and to estimate the effects of co-administered epidural analgesics. This study aimed at determining epidural bupivacaine's MAC-LA for orthopedic surgery. METHODS: A double-blind non randomized sequential allocation method for MAC calculation was applied to 23 adult patients undergoing orthopedic leg, ankle or foot surgeries. Anesthesia was obtained with lumbar spinal hyperbaric bupivacaine. An epidural catheter placed at L4-L5 level was inserted 3 to 5 cm in the cephalad direction. Postoperatively, a 20 ml epidural bupivacaine bolus followed by 0.15 ml.kg-1.h-1 infusion were administered at the appropriate concentration. Pain and Bromage scores were recorded after 4, 8 and 12 hours. Bupivacaine concentration was considered effective when visual analog pain scores were below 10 mm in all evaluations. Initial concentration was 0.3% and was subsequently decreased or increased by 0.1% for next patient when previous response was effective or ineffective, respectively. MAC-LA was calculated by Dixon and Massey's formula. RESULTS: Bupivacaine's MAC-LA (95% confidence limits) was 0.16% (0.11% and 0.21%). Intense motor blockade was observed in most patients. CONCLUSIONS: For a 0.15 ml.kg-1.h-1 infusion rate, bupivacaine's MAC-LA was 0.16%. However, the model may have not been suitable for the evaluation of motor effects of tested concentrations.

Keywords

ANALGESIA, ANESTHETICS, Local, ANESTHETIC TECHNIQUES, Regional, ANESTHETIC TECHNIQUES, Regional

References

Columb MO, Lyons G. Determination of the minimum local analgesic concentrations of epidural bupivacaine and lidocaine in labor. Anesth Analg. 1995;81:833-837.

Capogna G, Celleno D, Fusco P. Relative potencies of bupivacaine and ropivacaine for analgesia in labour. Br J Anaesth. 1999;82:371-373.

Polley LS, Columb MO, Naughton NN. Relative analgesic potencies of ropivacaine and bupivacaine for epidural analgesia in labor: implications for therapeutic indexes. Anesthesiology. 1999;90:944-950.

Columb MO, Polley LS, Wagner DS. Reduction in the minimum local analgesic concentration (MLAC) of bupivacaine by epidural sufentanil is dose dependent.. European J Anaesthesiol. 1997;14:549-550.

Polley LS, Columb MO, Wagner DS. Dose-dependent reduction of the minimum local analgesic concentration of bupivacaine by sufentanil for epidural analgesia in labor. Anesthesiology. 1998;89:626-632.

Polley LS, Columb MO, Lyons G. The effect of epidural fentanyl on the minimum local analgesic concentration of epidural chloroprocaine in labor. Anesth Analg. 1996;83:987-990.

Polley LS, Columb MO, Naughton NN. Effect of intravenous vs epidural fentanyl on the minimum local analgesic concentration (MLAC) of epidural bupivacaine in labor. Anesthesiology. 1999;90:25A.

Dixon WJ, Massey FJ. Introduction to Statistical Analysis. 1983:428-439.

Wulf HF. Up-down sequential allocation technique to investigate the influence of opioids on the efficacy of epidural local anesthetics in labor pain. Anesthesiology. 1999;90.

Columb MO, Polley LS. Up-down sequential allocation technique to investigate the influence of opioids on the efficacy of epidural local anesthetics in labor pain. Anesthesiology. 1999;90:1788-1789.

Columb MO, Lyons G, Polley LS. Bupivacaine requirements for labor analgesia. Anesthesiology. 1999;90:73A.

Capogna G, Celleno D, Lyons G. Minimum local analgesic concentration of extradural bupivacaine increases with progression of labour.. Br J Anaesth. 1998;80:11-13.

Galindo A, Benavides O, De Munos SO. Comparison of anesthetic solutions used in lumbar and caudal peridural anesthesia. . .

Arendt-Nielsen L, Oberg B, Bjerring P. Quantitative assessment of extradural bupivacaine analgesia.. Br J Anaesth. 1990;65:633-638.

Axelsson K, Nydahl PA, Philipson L. Motor and sensory blockade after epidural injection of mepivacaine, bupivacaine and etidocaine: a double-blind study. Anesth Analg. 1989;69:739-747.

Lund C, Hansen OB, Kehlet H. Effect of epidural 0.25% bupivacaine on somatosensory evoked potentials to dermatomal stimulation. Reg Anesth. 1989;14:72-77.

Galindo A, Hernandez J, Benavides O. Quality of spinal extradural anaesthesia: the influence of spinal nerve root diameter. Br J Anaesth. 1975;47:41-47.

Oliveira Fº GR, Pederneiras SG, Ghellar MR. Qualidade da anestesia das raízes L4, L5 e S1 com bupivacaína 0,5% epidural: efeitos da associação de fentanil por via epidural ou venosa. Rev Bras Anestesiol. 1996;46:CBA013.

Rygnestad T, Borchgrevink PC, Eide E. Postoperative epidural infusion of morphine and bupivacaine is safe on surgical wards. Organisation of the treatment, effects and side-effects in 2000 consecutive patients.. Acta Anaesthesiol Scand. 1997;41:868-876.

Scott DA, Beilby DS, McClymont C. Postoperative analgesia using epidural infusions of fentanyl with bupivacaine. A prospective analysis of 1,014 patients.. Anesthesiology. 1995;83:727-737.

Bogod DG, Rosen M, Rees GA. Extradural infusion of 0.125% bupivacaine at 10 m.h-1 to women during labour.. Br J Anaesth. 1987;59:325-330.

Stienstra R, Dahan A, Alhadi BZ. Mechanism of action of an epidural top-up in combined spinal epidural anesthesia. Anesth Analg. 1996;83:382-386.

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