Paraspinal Muscle Relaxation in Spine Surgery
Condition: Paraspinal Muscle Relaxation in Spine Surgery
Study type: Interventional

Summary: 
      During anesthesia, neuromuscular blocking agents (NMBA) are routinely used for relaxation of
      muscles necessary for the conduction of the surgical procedure. Train-of-four (TOF) test is
      based on supramaximal stimulation of peripheral nerve resulting in four twitches: T1 to T4.
      The assessment of the NMBA blockade is performed routinely by measurement of the amplitude of
      compound muscle action potential (CMAP) and calculation of percentage of CMAP decrement from
      T1 to T4.

      Train-of-four monitoring is routinely performed during spine surgery by stimulation of the
      ulnar nerve. Furthermore motor evoked potentials (MEPs) are routinely used in intraoperative
      neuromonitoring to assess the whole motor pathway from the cortical level down to the distal
      muscle. During anesthesia MEPs are routinely evoked by transcranial electrical stimulation
      with single or short train stimuli. In clinical practice even though full muscle relaxation
      of the hand by NMBA can be observed, utilizing the TOF test, remaining muscle tonus can be
      observed at the paraspinal musculature during spine surgery.

      The goals of this study are to determine (1) if any differences between muscle relaxation of
      the hand and foot (measured by TOF test and MEPs) and MEPs of the paraspinal musculature
      occur; (2) how much more NMBA must be administered to achieve full muscle relaxation of the
      paraspinal musculature in comparison to the hand or foot.
    

Detailed description: 
      Muscle relaxation during surgery will be performed using intraoperative boli intermediate
      duration non-depolarizing NMBA, rocuronium (0.3 mg/kg) until TOF 0 at the hand is achieved.
      TOF measurements will be performed at baseline 5 minutes after induction. Moreover, TOF
      measurements will be performed 5 minutes after each rocuronium bolus. When TOF 0 at the hand
      is achieved the MEPs of the paraspinal musculature will be measured. When there is remaining
      muscle tonus of the paraspinal musculature another bolus of rocuronium is administered until
      no MEPs can be measured for the paraspinal musculature.
    

Intervention name(s): Anesthesia with non-depolarizing NMBA Rocuronium; TOF measurement; MEP measurement
Intervention type(s): Drug; Diagnostic Test; Diagnostic Test
Intervention description(s): 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.
Intervention MeSH terms: Rocuronium
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Treatment