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Influence of Dexmedetomidine on the Evoked Potentials During Spine Surgery

This study has been completed.
Hospira, Inc.
Information provided by (Responsible Party):
University of Washington Identifier:
First received: June 28, 2007
Last updated: September 12, 2012
Last verified: September 2012

The purposes of this study are:

  1. To evaluate the safety and efficacy of Dexmedetomidine as an adjunct for anesthesia during spine surgery and
  2. To investigate the influence of Dexmedetomidine on the evoked potentials.

Condition Intervention
Spine Surgery
Drug: Dexmedetomidine
Drug: Normal Saline

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Influence of Dexmedetomidine on the Evoked Potentials During Spine Surgery

Resource links provided by NLM:

Further study details as provided by University of Washington:

Primary Outcome Measures:
  • Change in evoked potentials [ Time Frame: Duration of surgery ]

Enrollment: 40
Study Start Date: February 2008
Study Completion Date: May 2010
Primary Completion Date: May 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Dexmedetomidine
Dexmedetomidine infusion
Drug: Dexmedetomidine

10 minutes loading dose of 0.9 mcg/kg

Maintenance dose of 0.6 mcg/kg/hour

Other Name: Dexmedetomidine hydrochloride
Placebo Comparator: Placebo
Normal Saline infusion
Drug: Normal Saline

10 minutes loading dose of 0.9 mcg/kg

Maintenance dose of 0.6 mcg/kg/hour

Other Name: 0.9% Sodium Chloride

Detailed Description:

Use of evoked potentials can significantly improve neurologic outcome after major spine surgery. Modalities of evoked potentials commonly used are Somato-Sensory Evoked Potentials (SSEP's), Motor Evoked Potentials (MEP's), and Visual Evoked Potentials (VEP's).

Dexmedetomidine (DEX) is an alpha-2 agonist and has been FDA approved as an adjunct sedative agent to general anesthesia. It has been purported to reduce the amount of anesthetic required and potentiate the analgesic effect of opiates. In addition, DEX was shown to have minimal effect on SSEP's and VEP's in both rats and humans. Any decrease in the dose of general anesthesia that improves the monitoring of evoked potentials, supports DEX as an adjunct.

It is known that all anesthetic agents can interfere with the recording of evoked potentials. The choice of anesthetic however, depends on the modality of neurophysiologic monitoring planned for the patient. Total intravenous anesthesia (TIVA) and Sevoflurane, a low dose inhalational anesthetic are the usual agents for spine surgery. Both have a dose-related depressant effect on the quality of evoked potentials. As a result, it is common practice for the anesthesiologist to adjust the depth of anesthesia to improve signaling. The use of either anesthetic must accompany continuous infusion of Propofol and an opioid, Remifentanil or Fentanyl. The anesthesiologist then decides whether DEX should be as an adjunct. In our experience, DEX did not impair evoked potentials. In fact, it improved the quality of signals in a few patients. Yet, there are no published data of such effects in medical literature.

We hypothesize that Dexmedetomidine will not influence evoked potentials when used as an adjunct to general anesthesia. Our study is prospective, randomized, double-blinded and will be carried out on a set of anesthetics. We will first evaluate DEX as an adjunct in TIVA, then as an adjunct to Sevoflurane. The probable benefit of DEX may avoid the use of potent inhaled anesthetics which would improve VEP's monitoring. Quality recording of evoked potentials can enhance our ability to detect iatrogenic injury to the spinal cord and vision.


Ages Eligible for Study:   18 Years to 80 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Adult spine surgery patients requiring evoked potentials monitoring.

Exclusion Criteria:

  • Age younger than 18 and older than 80 years
  • Patients with moderate neurological deficit
  • ASA grade above 3
  • Any chronic psychiatric disorder
  • Body mass index (BMI) above 35
  • Patients with cortical blindness, cataracts, retinal or optic neuropathy, glaucoma, untreated diabetes, active hepatitis, active coronary artery disease, untreated arrhythmias and patients with renal or hepatic insufficiency
  Contacts and Locations
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Please refer to this study by its identifier: NCT00494832

United States, Washington
Harborview Medical Center
Seattle, Washington, United States, 98104
University of Washington Medical Center
Seattle, Washington, United States, 98195
Sponsors and Collaborators
University of Washington
Hospira, Inc.
Principal Investigator: Irene Rozet, MD University of Washington
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: University of Washington Identifier: NCT00494832     History of Changes
Other Study ID Numbers: 31416-A
064705 A01 ( Other Identifier: University of Washington )
Study First Received: June 28, 2007
Last Updated: September 12, 2012

Keywords provided by University of Washington:
Evoked potentials
Spine surgery

Additional relevant MeSH terms:
Hypnotics and Sedatives
Central Nervous System Depressants
Physiological Effects of Drugs
Analgesics, Non-Narcotic
Sensory System Agents
Peripheral Nervous System Agents
Adrenergic alpha-2 Receptor Agonists
Adrenergic alpha-Agonists
Adrenergic Agonists
Adrenergic Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action processed this record on March 29, 2017