A prospective, double-blinded, randomized controlled trial to evaluate the efficacy of intravenous nefopam on postoperative opioid consumption after laparoscopic liver surgery

INTERVENTION: 20 mg of nefopam diluted in 0.9%NSS up to 100 ml IV drip in 30 minutes at the end of surgery and then 60 mg of nefopam diluted in 0.9%NSS up to 500 ml IV continuous for 24 hours,receiving placebo as intravenous 100 ml of normal saline and then 500 ml of normal saline continuous infusion for 24 h Active Comparator Drug,Placebo Comparator No treatment Nefopam,Control CONDITION: Nefopam, Laparoscopic liver surgery, Postoperative pain, Opioid consumption Patients after laparoscopic liver surgery ; Nefopam, Laparoscopic liver surgery, Postoperative pain, Opioid consumption PRIMARY OUTCOME: Cumulative morphine consumption in 24 hours At 24 hours postoperatively Data from IV PCA machine SECONDARY OUTCOME: Postoperative pain score At 0, 1, 6, 12, 24, 48 hours postoperatively Numeric rating scale,Incidence of adverse effects During 24 hours postoperatively Dry mouth, profuse sweating, nausea, and vomiting INCLUSION CRITERIA: 1. Age 18‐65 years old 2. Patient who undergoing laparoscopic liver surgery 3. ASA classification I‐III