The Effect of Intraoperative Ketamine and Magnesium Sulfate on Acute Pain and Opioid Consumption After Spine Surgery

Ketamine and magnesium in brain act as an n-methyl-d-aspartate receptor antagonist that has been shown to be useful in the reduction of acute postoperative pain and analgesic consumption in a variety of surgical interventions. we hypothesized that combination of low dose ketamine and magnesium would reduce early postoperative opiate consumption and analgesic requirement after 6 weeks. this was a randomized, prospective, controlled-placebo trial involving elective and eligible patients undergoing lumbar spine surgery. seventy patients in the treatment group were administered 0.5 mg/kg intravenous ketamine and 1 gram of magnesium as an intravenous bolus slowly during 3 minute before incision and 0.25 mg/kg/hr ketamine and 0,5 g/hr magnesium intravenous infusion during surgery. seventy patients in the placebo group received saline of equivalent volume. patients were observed for48 h postoperatively and followed up at 6 weeks. the primary outcome was 48h morphine consumption. the severity of pain was lower in the intervention group than in the placebo group during 48 hr post-operatively, morphine consumption in this group also decreased significantly during this period. intraoperative ketamine-magnesium reduces opiate consumption in the 48-h postoperative period. this combination may also reduce pain intensity throughout the postoperative period in this patient population.