[Synergistic effect between dexmedetomidine and 0.75% ropivacaine in epidural anesthesia]. / Efeito sinérgico entre a dexmedetomidina e a ropivacaína 0,75% na anestesia peridural.

ABSTRACT

BACKGROUND: This study aimed to evaluate clinical characteristics of epidural anesthesia performed with 0.75% ropivacaine associated with dexmedetomidine. METHODS: Forty patients scheduled for hernia repair or varicose vein surgeries under epidural anesthesia participated in this study. They were assigned to Control Group (n = 20), 0.75% ropivacaine, 20 ml (150 mg); and Dexmedetomidine Group (n = 20), 0.75% ropivacaine, 20 ml (150 mg), plus dexmedetomidine, 1 mg x kg-1. The following variables were studied total analgesic block onset time, upper level of analgesia, analgesic and motor block duration time, intensity of motor block, state of consciousness, hemodynamics, postoperative analgesia and incidence of side-effects. RESULTS: Epidural dexmedetomidine did not affect onset time or upper level of anesthesia (p > 0.05) however it prolonged sensory and motor block duration time (p < 0.05) and postoperative analgesia (p < 0.05), and also resulted in a more intense motor block, l (p < 0.05). Values of bispectral index were lower in Dexmedetomidine Group (p < 0.05). There was no difference in incidence of hypotension and bradycardia (p > 0.05). Occurrence of side-effects (shivering, vomiting and SpO2 < 90%) was low and similar between groups (p > 0.05). CONCLUSION: There is clear synergism between epidural dexmedetomidine and ropivacaine, further this drug association does not bring about additional morbidity.