- A manometer to control the tracheal tube cuff pressure Before anesthesia induction, patients will breathe 100% oxygen till expired oxygen concentration reach 90%. Intravenous anesthesia will be then performed with propofol (1.5-2.5 mg kg -1) as hypnotic, sufentanil (0.2 mcg kg-1) and atracurium (0.5 mg kg-1) as muscle relaxant. Cis-atracurium or vecuronium as middle acting muscle relaxant or SUNCCYNILCHOLINE as short acting muscle relaxant will be authorized. According to the randomization, the blade used for orotracheal intubation will be metal or plastic. The metal blade is reusable and the plastic blade is disposable. When the BIS or the entropy will reach 40-60 and 25-35, respectively, with efficient face mask ventilation (good thoracic amplitude following by capnography cycles), no response to the TOF at the corrugator Supercilia, the laryngoscopy will be performed according to the orotracheal intubation algorithm. Tracheal tube sizes will be 7 mm for female and 7.5 for males. Tracheal tube cuff will be standard.