A (+)-CETAMINA NÃO APRESENTA EFEITO PREEMPTIVO QUANDO USADA EM DOSES SUBANESTÉSICAS, EM ANESTESIA GERAL PARA COLECISTECTOMIA CONVENCIONAL

THE S-KETAMINE DIDN’T PRESENT NOTHING EFFECT PREEMPTIVE WHEN USED IN SUB-ANESTHETIC DOSES, IN GENERAL ANESTHESIA FOR CONVENTIONAL CHOLECYSTECTOMY

Kleber Machareth de Souza1, Luiz César Anzoategui2, Francisco Otaviano Ilgenfritz1, Luiz Gustavo Orlandi de Souza3, Ricardo Correa Gonzales3

1 - Anestesiologista do Serviço de Anestesiologia da Santa Casa de Campo Grande - MS.

2 - Anestesiologista Responsável pelo CET/SBA - Santa Casa de Campo Grande - MS.

3 - ME2 do CET – Santa Casa de Campo Grande - MS.

RESUMO

Justificativa e Objetivos: O enantiômero S(+) da cetamina apresenta superioridade quanto à potência analgésica e menor incidência de efeitos colaterais quando comparado à mistura racêmica. Recentes estudos têm tentado demonstrar que o enantiômero S(+) da cetamina pode ser capaz de promover analgesia preemptiva, melhorando não somente a qualidade da analgesia pós-operatória, como também sendo capaz de produzir efeito poupador opióide. A promoção de analgesia preemptiva vem sendo motivo de grande controvérsia entre diversos autores no que se refere à concepção conceitual do processo de combate à nocicepção, tendo sido proposto o termo analgesia preventiva ao invés de analgesia preemptiva, uma vez que segundo alguns autores o efeito analgésico em si seria semelhante em ambas as técnicas, seja preemptiva, seja preventiva. A S(+) cetamina também foi capaz de reduzir o consumo global de agentes anestésicos quando utilizada em regime de infusão contínua durante todo o período pós-operatório. Tanto o efeito analgésico preemptivo, como a capacidade de reduzir o consumo global de agentes anestésicos no período transoperatório associados a S(+) cetamina, vêm sendo obtidos com a administração de doses subanestésicas e subanalgésicas, tanto no período pré-operatório como no período transoperatório. Método: Avaliou-se durante o referido estudo a dor pós-operatória, pela escala analógica visual (EAV), o consumo de opióide como medicação analgésica de resgate. Ao final do procedimento administrou-se morfina (0,1 mg.kg-1) por via venosa visando controle inicial da dor pós-operatória. Resultados: Idade, sexo, índice de massa corpórea e grau de analgesia foram analisados estatisticamente no presente estudo. Para analisar o comportamento do consumo de isoflurano e alfentanil, e escala de dor ao longo do tempo (oito avaliações) separadamente por grupo de tratamento e cetamina S(+) foi realizada a Análise de Variância para medidas repetidas. O teste de comparações múltiplas de Bonferroni (paramedidas repetidas) foi aplicado para identificar quais os momentos que diferem entre si. O teste de comparações múltiplas é um teste complementar à Análise de Variância, para verificar se a evolução do consumo (ou escala de DOR) ao longo do tempo é diferente entre os dois grupos de tratamento foi realizada a Análise de Variância para medidas repetidas com um fator. O critério de determinação de significância adotado foi o nível de 5%,  ou seja, quando o valor de p = 0,05. Conclusão: Não houve diferenças estatisticamente significativas no escore da dor quando comparados ambos os grupos.

Unitermos: Colecistectomia, analgesia pré e pós-operatória, anestesia geral, analgesia preemptiva, cetamina-S(+).

ABSTRACT

Justification and Objectives: The enantiomer S-ketamine, it presents superiority as for the analgesic potency and smaller incidence of side effects when compared to the racemic mixture. Recent present studies in the literature have been trying to demonstrate that the enantiomer S-Ketamine it can be capable to promote preemptive analgesia, getting better not only quality of the postoperative analgesia, as well as being capable to produce reduction in consumption of opioids. The promotion of preemptive analgesia is being great reason controversy among several authors in what for refers to the conceptual conception of the combat process the nociception, having been proposed the term preventive analgesia instead of preemptive analgesia, once second some authors the analgesic effect in itself would be similar in both techniques, being preemptive analgesia, or preventive analgesia. S-Ketamine was also capable, during accomplished studies, of global reduction consumption of anesthetic agents when used in regime of continuous infusion during the whole postoperative period. So much the effect preemptive analgesic, as the capacity in global reducing consumption of anesthetic agents in per operative period associate S-ketamine, it has been obtained with the administration of sub-anesthetic and sub-analgesic doses, so much in the preoperative period, as in the intraoperative period. Method: Twenty-four patient were separated in two groups of 12 patient submitted to the conventional cholecystectomy. The technique anesthetic pattern was accomplished with propofol (2,5 mg/Kg), alfentanil (25µg/Kg), lidocaine (1 mg/Kg) and rocuronium (0,6 mg/Kg). The maintenance of the anesthesia was accomplished with oxygen to 100%, isoflurane through universal vaporizer and alfentanil in continuous infusion (0,25 the 1 µg/kg/min). During the maintenance of the anesthesia chose initially, when necessary, for the gradual reduction for the infusion rhythms of the alfentanil in fractional doses previous described, associated to the reduction if necessary for the administration of the isoflurane through the use of universal vaporizer. In the group S-ketamine, S-ketamine (0,1 mg/kg) was intravenous administered during anesthetic induction and maintenance with S-ketamine (5 µg/kg/min) in continuous venous infusion during the whole surgical procedure. In the group placebo, it proceeded the administration of physiologic solution for 0,9% instead of S-ketamine in syringes and infusion pumps strictly similar in both groups. It was evaluated during referred study the postoperative pain, through scale analogical visual (EAV), the opioid consumption as medication analgesic rescue, the isoflurane consumption through the evaluation of the graduate universal vaporizer and the alfentanil. To the end of the procedure morphine was managed (0,1 mg.kg-1) for IV, aiming at initial control of postoperative pain. Result: Age, sex, index of corporal mass and analgesia degree were analyzed statistically in the present study To analyze the behavior of the consumption of isoflurane, alfentanil, and scale of PAIN along the time (eight evaluations) separately for treatment group (Distilled Water and S-ketamine) the Variance Analysis was accomplished for repeated measures. The Test of Multiple Comparisons of Bonferroni (for repeated measures) it was applied to identify which the moments it differ amongst themselves. The test of multiple comparisons is a  complementally test the Analysis Variance, to verify the evolution of the consumption (or scale of pain) along the time that it is different among the two treatment groups, the Analysis Variance was accomplished for repeated measures with a factor. The criterion of determination of adopted significance was the level of 5%, in other words, when the value of p = 0,05. Conclusion: When it looked for if it evaluates the isoflurane consumption and alfentanil comparatively along the time it can be observed that there were not differences significant statistically between both the groups. However it was observed that both anesthetic agents, isoflurane and alfentanil, presented a consumption increase in the final period of the procedure in the group Distilled Water when compared to the group S-ketamine. In relation to the profile of pain, being used the Analogical Scale Numeric Visual as quantitative method of evaluation, a better profile was observed, in than refers to the analgesic control in the postoperative period, in the group S-ketamine, in spite of there not being differences significant statistically in the score of pain when compared both groups.

Keywords: Cholecystectomy, analgesia intra and postoperative, anesthesia general, analgesia preemptive and S-ketamine.

Endereço para correspondência:

Kleber Machareth de Souza

E-mail: kleber.machareth@terra.com.br