Intraoperative infusion of lidocaine reduces postoperative fentanyl requirements in patients undergoing laparoscopic cholecystectomy

Background: Lidocaine has been shown to inhibit neural conduction and to have anti-inflammatory properties. The purpose of this study was to determine whether intraoperative lidocaine infusion reduces opioid consumption in the postanesthesia care unit (PACU). Methods: Fifty patients were enrolled in this prospective, randomized and observer-blinded study. At induction of anesthesia the control group (n = 25) received fentanyl 3 mu g.kg(-1) while the lindocaine group received fentanyl 1.5 mu g.kg(-1) and a bolus of lidocaine 1.5 mg.kg(-1) followed by a continuous infusion of lidocaine 2 mg.kg(-1).hr(-1). General anesthesia included propofol, rocuronium, and desflurane titrated to maintain blood pressure and heart rate within set parameters, and the bispectral index between 35 and 50. No supplemental opioids were given during surgery. All patients received acetaminophen, ketorolac, dexamethasone, droperidol and local anesthetics in the skin incision. Patients received fentanyl and ondansetron in the PACU. The primary outcome variable was the amount of fentanyl required in the PACU to establish and to maintain visual analogue scale pain scores < 3. Results: Most patients received fentanyl for pain relief in the PACU, but the cumulative mean dose was lower in the lidocaine group compared to the control group (98 +/- 54 mu g, vs 154 +/- 99 mu g, respectively, P = 0.018). Lidocaine infusion reduced by 10% the amount of desflurane required (P = 0.0 12). White-Song scores > 12 were attained by all patients in both groups within 30 min of their arrival in the PACU. Median time from arrival to the PACU to discharge home was similar in both groups, 167.5 min in the control group vs 180 min in the lidocaine group (P = 0.649). Conclusion: Intraoperative lidocaine infusion reduces opioid consumption in the PACU and intraoperative requirements of desflurane.