Study protocol
MUSCLE RELAXATION
Standard anaesthesia monitoring and study instrumentation were established upon arrival in the operating theatre. Anaesthesia was induced with sufentanil or remifentanil, lidocaine and propofol. The airway was maintained with either a laryngeal mask or tracheal intubation after muscle relaxation with rocuronium. Anaesthesia was maintained with either propofol (6 to 7 mg kg