Perioperative intravenous lidocaine infusion on postoperative pain relief in patients undergoing upper abdominal surgery.

Due to unpleasant nature and physiological consequences of postoperative pain, search of safe and effective modalities for its management has remained a subject of interest to clinical researchers. Analgesic action of lidocaine infusion in patients with chronic neuropathic pain is well known but its place in relieving postoperative pain is yet to be established. The study aimed to assess the effectiveness of perioperative intravenous lidocaine infusion on postoperative pain intensity and analgesic requirement. Sixty patients undergoing major upper abdominal surgery were recruited in this randomized double blinded study. Thirty patients received lidocaine 2.0% (intravenous bolus 1.5 mg/kg followed by an infusion of 1.5 mg/kg/h), and 30 patients received normal saline according to randomization. The infusion started 30 min before skin incision and stopped 1 h after the end of surgery. Postoperative pain intensity and analgesic (diclofenac) requirement were assessed at the interval 15 minutes for 1 hour then 4 hourly up to 24 hours. The pain intensity at rest and movement as well as the total postoperative analgesic (diclofenac) requirement were significantly lower (142.50 +/- 37.80 mg vs.185.00 +/- 41.31 mg, P<0.001) in lidocaine group. The extubation time was significantly longer in lidocaine group (14.43 +/- 3.50 minutes vs. 6.73 +/- 1.76 minutes, P<0.001). The time for the first dose of analgesic requirement was longer in lidocaine group (60.97 +/- 18.05 minutes vs.15.73 +/- 7.46 minutes, P<0.001). It can be concluded that perioperative infusion of low dose of lidocaine decreases the intensity of postoperative pain, reduces the postoperative analgesic consumption, without causing significant adverse effects in patients undergoing upper abdominal surgery.