Motor Evoked Potentials and SedLine
Motor Evoked Potentials and SedLine
To determine if using usual clinical practice plus a depth of anesthesia monitor, SedLine, to
 guide anesthetic administration improves the quality and ease of MEP monitoring in patients
 undergoing corrective spinal procedures.
Motor Evoked Potential (MEP) monitoring during spine surgery is now used routinely. However
 it is affected by a variety of anesthetics including fluctuating and/or excessively deep or
 light levels of anesthesia. A common problem is maintaining an overall constancy and adequacy
 of anesthesia. Individual patients' responses to anesthesia can differ greatly from
 population means and can complicate the interpretation of MEPs. False alarms can have
 significant consequences. One strategy to minimize the anesthetic induced variability of
 MEPs, and thereby improve the monitoring overall, is to keep the patient's anesthetic state
 (or "depth") in a narrow range during surgery. This study tests whether using a commercially
 available depth of anesthesia monitor in addition to usual clinical practice improves the
 quality of MEPs.

 The hypothesis of this study is that the SedLine Monitor, which uses an EEG derived
 assessment of anesthetic depth, may facilitate MEP monitoring if it is kept within a narrow
 range during spine surgery. Because SedLine recommends maintaining their Index between 30 and
 40 during surgical anesthesia, this is the range used in the primary hypothesis.
Inclusion Criteria:

 -  Patients undergoing corrective spinal procedures, for whom MEP monitoring has been
 requested by the surgeon.

 -  18 yrs of age or older

 Exclusion Criteria:

 -  Minors, prisoners and those unable to consent for themselves.