[Effect of dexmedetomidine in acute postoperative pain relief is independent of suppressing the hyperalgesia induced by remifentanil].

OBJECTIVE: To explore the effect of dexmedetomidine in acute postoperative pain and remifentanil-induced hyperalgesia. METHODS: From January 2011 to June 2012, 120 patients scheduled for elective abdominal surgery under general anesthesia were included in this study. All patients received intravenous remifentanil infusion during operation, and dexmedetomidine was given after anesthesia induction. The postoperative mechanical pain threshold, pain visual analog scale (VAS) score, morphine consumption, and score of sedation (Ramsay) was recorded. RESULTS: Relatively large-dose intraoperative remifentanil resulted in lower mechanical pain threshold and higher dose of postoperative morphine consumption. Dexmedetomidine reduced postoperative morphine consumption significantly, and increased Ramsay scores, but had no effect on mechanical hyperalgesia. CONCLUSION: Dexmedetomidine can alleviate the acute postoperative pain effectively, but the effect is not dependent on inhibiting remifentanil-induced hyperalgesia.