Effect of Lidocaine 1% and 2% in the Tube Cuff on Postoperative Sore Throat and Cough

Eligible patients undergoing general anesthesia will be randomized and assigned to three groups: Group A: Endotracheal tube cuff inflation with air Group B: Endotracheal tube cuff inflation with Lidocaine 1% Group C: Endotracheal tube cuff inflation with Lidocaine 2% The induction of anesthesia will be made following a preoxygenation with a facial mask with 100% Oxygen. It consists on the intravenous injection of Sufentanil 5 mcg or Fentanyl 50mcg, Lidocaine 1mg/Kg, Propofol 2.5mg/kg, Rocuronium 0.6mg/kg or Cisatracurium 0.15mg/kg. Maintenance of anesthesia will be done by sevoflurane + nitrous oxide, and reinjections of morphinomimetics and curare will be made as needed (the total doses will be noted at the end of the intervention). The intubation is made by a N° 7.5 tube in men and a N° 7 tube in women. Cuff inflation will be done upon placement of the endotracheal tube. The cuff's pressure will be monitored at several intervals of the intervention and kept < or = 20 centimeter of water (cmH2O). The volume of lidocaine used will never exceed 5 mg / kg for the patient to be protected from the local toxicity of the local anesthetic in case of accidental rupture of the balloon. All patients will receive Paracetamol every 6 hours for the first 24 hours after the end of surgery.