Measuring the Effects of Dexmedetomidine on Somatosensory Evoked and Muscular Evoked Potential During Neurosurgery in Pediatric Patients
Somatosensory evoked potential (SSEP) and motor evoked potential (MEP) have become an
integral component in intraoperative care of patients and have resulted in a high degree of
sensitivity in predicting neurologic outcomes. According to Padberg, Nuwer and Ecker ,SSEP
and MEP monitoring allows surgical interventions to occur early and thus decreases the
incidence of postoperative neurologic deficits.
These measurements are done during surgery under general anesthesia and it is known that
anesthetic agents have a dose-dependent adverse effect on the ability to record evoked
potential responses. All anesthesia agents seem to interfere with the measurements
especially in higher doses.
In 1999, dexmedetomidine, a highly specific and selective alpha-2-adrenergic agonist with
sedative, anxiolytic and analgesic effects, got FDA approved for adult patients for
sedation. Since then, it has also been widely used off-label in various settings; it is
described as a successful adjunct for surgical procedures in adolescents and adult
populations where SSEP/ MEP monitoring is beneficial. Several small and retrospective
studies have shown that dexmedetomidine does not appear to interfere with neurophysiological
monitoring when used in FDA approved doses.
In pediatric patients, dexmedetomidine is also used off-label and has been shown to be
beneficial. In fact, at Doernbecher Childen's Hospital, the use of dexmedetomidine has
become a standard in pediatric procedures involving SSEP and MEP measurements. To the best
of our knowledge, prospective studies in pediatric patients with SSEP monitoring while using
dexmedetomidine have not been completed.
If dexmedetomidine does not interfere the SSEP/MEP reading, it might be an advantageous
adjunct to use in these settings. Propofol has a small risk of a serious side effect called
propofol infusion syndrome. Propofol infusion syndrome is potentially life threatening, with
the development of a profound lactate acidosis. It is seen when large doses of propofol
(usually from a prolonged infusion) are given in the pediatric population.
Endpoint Classification: Safety Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Prevention
Significant improvement of MEP and SSEP readings during neurosurgery for pediatric patients while using dexmedetomidine as an adjunct to general anesthesia and therefore improvement in clinical decision making.
Changes in latency and amplitude of SSEP and changes in amplitude and morphology of MEP while using different anesthetic combinations including isoflurane, propofol and dexmedetomidine.
30 - 60 minutes of SSEP and MEP measurements intraoperatively
Heike Gries, MD, PhD
Oregon Health and Science University
United States: Institutional Review Board
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