The effects of magnesium sulfate infiltration on perioperative opioid consumption and opioid-induced hyperalgesia in patients undergoing robot-assisted laparoscopic prostatectomy with remifentanil-based anesthesia.

Background: Opioids not only exert an antinociceptive effect, but also modulate central N-methyl-D-aspartate (NMDA) receptors, resulting in hyperalgesia and acute opioid tolerance. This study was aimed to investigate the effect of the NMDA receptor antagonist, magnesium in preventing remifentanil-induced hyperalgesia.

Methods: For this study, 75 patients scheduled for robot-assisted laparoscopic prostatectomy were randomly allocated into three groups of patients whose incision sites were infiltrated: Group M, with 25% magnesium sulfate 80 mg/kg; Group S, with the same volume of saline under remifentanil-based anesthesia, and Group D, with the same volume of saline under desflurane based anesthesia.