Intravenous Lidocaine in Bariatric Surgery. (XYLOBAR)

Effect of Continuous Intravenous Lidocaine on Early Rehabilitation in Bariatric Surgery. A Randomized Double Blind Controlled Study

Although peroperative intravenous lidocaine has been shown to be useful in early recovery after colorectal surgery, its beneficial effect on the specific population of obese patients scheduled for bariatric surgery remained unknown. Investigators hypothesized that peroperative intravenous lidocaine could decrease postoperative opioid consumption and improve postoperative recovery

This is a prospective, double-blind, placebo-controlled, monocentric study. We plan to recruit 180 obese adult patients scheduled for bariatric surgery in a the french university hospital of Caen. Exclusion: contra-indications for any aminoamide local anesthetic (allergy, severe hepatic disease) and for intravenous lidocaine (porphyria, atrioventricular conduction disturbances, uncontrolled seizure disease), long term opioid consumption, need for a post-operative follow-up in an intensive care unit, combined surgical procedure excepting cholecystectomy, pregnancy. Patients will be randomly allocated to receive either a saline placebo or lidocaine continuous infusions during surgery. Morphinic consumption will be assessed from the end of the procedure until the third day after surgery. Secondary criteria will concern post-operative recovery, pain and postoperative nausea and vomiting, other medical and surgical complications, and toxicity. Plasma lidocaine concentrations will be measured in patients who had received lidocaine in order to determine the safety and efficiency of our infusion protocol. Our analysis will be a superiority one, alpha risk is 5% and beta risk is 20%, in intention to treat, with no intermediate analysis.

intravenous isotonic saline administration : bolus of 0.075 ml/kg (adjusted body weight) at induction of anesthesia followed by a continuous infusion (0.1 ml/kg/h, adjusted body weight) until the end of surgery decrease to 0.05 ml/kg (adjusted body weight) during 60 min in post anesthesia care unit. Speed of infusion were calculated to be equivalent to that of lidocaine speed of injection.

Intravenous Lidocaine (20mg/ml) : bolus of 1.5 mg/kg (adjusted body weight) at induction of anesthesia followed by a continuous infusion (2.0 mg/kg/h, adjusted body weight) until the end of surgery decrease to 1.0 mg/kg (adjusted body weight) during 60 min in post anesthesia care unit.

Inclusion Criteria: scheduled bariatric surgery Exclusion Criteria: any contra-indication for lidocaine administration pregnancy ASA class 4 psychiatric disorder chronic opioid consumption