Paraspinal Muscle Relaxation in Spine Surgery

Non- depolarizing NMBA Rocuronium will be used until full paraspinal muscle Relaxation. Muscle relaxation during surgery will be performed using intraoperative boli intermediate duration non-depolarizing NMBA, rocuronium (0.3 mg/kg) until good surgical conditions are achieved.

TOF (Train-of-four) measurements will be performed at baseline 5 minutes after induction after the effect of succinylcholine will have run off. Moreover, TOF measurements will be performed 5 minutes after each rocuronium bolus

MEPs (motor evoked potentials) are routinely obtained after intubation and before surgery, then every 10min during the critical preparation and closing phases of surgery and every 5min during the correction phase. In addition MEPs will be measured after the administration of the NMBA rocuronium. Baseline values for amplitudes and latencies are obtained directly prior to the start of the correction phase of the surgery.