Anesthesiologic Management Effect on Perioperative Outcome in Scoliosis Surgery
Anesthesiologic Management Effect on Perioperative Outcome in Scoliosis Surgery
Alteration of evoked potentials is described in cases with using inhalation anaesthetics.
 Muscle relaxants are contraindicated in case of motor evoked potentials except for initial
 dose for intubation of the patient. Dominant anaesthetic method for procedures with measuring
 motor evoked potentials is total intravenous anaesthesia (TIVA). Bispectral index (BIS)
 monitoring is one of the possible options for comprehensive monitoring of the depth of
 general anaesthesia. It helps to optimize the management of anaesthesia, so it reduces the
 risk of perioperative awakenings due to shallow anaesthesia or inadequate depth of
 anaesthesia associated with the risk of cognitive dysfunction, as well as investigators
 expect worse interpretation of motor evoked potentials. At the same time, it shortens the
 time to wake up from general anaesthesia after hours-long surgery. BIS monitoring allows
 optimizing the depth of anaesthesia and leads to improve quality and interpretation of motor
 evoked potentials. The depth of TIVA managed by BIS affects the reproducibility of motor
 evoked potentials.
SCOL study is designed as a prospective observational study. We will monitor patients with
 scoliosis suitable for TIVA with BIS monitoring after the approval by the ethical committee
 of the University Hospital Brno and the Faculty of Medicine of Masaryk University in Brno,
 Czech Republic. The study period is planned from 1st September 2020 to 31st December 2024.
 Anaesthesia will be maintained following standardized local protocol for scoliosis surgery,
 include preoperative preparation and premedication. General anaesthesia will be performed in
 TIVA mode,combining propofol and remifentanil with titration to the target BIS value. Motor
 evoked potentials will be measured and evaluated by members of operating team
 perioperatively. The evocation of reproducible motor evoked potential and the actual value of
 amplitude and latency at different BIS levels (40 - 60) will be monitored. Motor evoked
 potentials (MEP) reproducibility will be based on standardized orthopaedic practice,
 according to the amplitude, latency of the MEP. The reproducibility will be monitored in
 defined surgery phases: before skin incision at the different BIS levels, next after screw
 application, rod applications, after distraction and the last one before wound suturing. At
 the same time, the BIS value is recorded.

 In addition to the MEP reproducibility, investigators will measure the amplitude and latency
 value. These parameters and actual BIS value will be monitored in each patient after the
 recovery from neuromuscular blockade (TOF ratio value above 90%) to eliminate the influence
 of neuromuscular blockade on neurophysiology monitoring. Due to individual variability in the
 MEP latency and amplitude in these patients, the initial MEP value will be set as the default
 (100%), and other values will be expressed as a percentage.

 Other monitored parameters in this study will be blood loss, blood derivates and transfusion
 products administered to the patient in first 24 hours after surgery, the time between the
 end of the surgery and extubation, neurological complications, number of surgical revisions
 and a total length of hospitalization.

 The annual number of scoliosis operations at the University hospital Brno is around 130
 patients. It is the largest surgery centre in Central Europe.
Inclusion Criteria:

 -  Patients indicated for scoliosis surgery with perioperative MEP monitoring

 Exclusion Criteria:

 -  Scoliosis surgery without perioperative MEP monitoring

 -  Contraindication for perioperative MEP monitoring

 -  Contraindication of using propofol (soy, egg lecithin or peanuts allergy,...) or other
 drugs used for anaesthesia

 -  The inability of attachment of BIS electrodes to the standard position