Influence of Dexmedetomidine on the Evoked Potentials During Spine Surgery

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00494832
Recruitment Status : Completed
First Posted : July 2, 2007
Last Update Posted : September 14, 2012
Hospira, now a wholly owned subsidiary of Pfizer
Information provided by (Responsible Party):
University of Washington

Brief Summary:

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 or disease Intervention/treatment Phase
Spine Surgery Drug: Dexmedetomidine Drug: Normal Saline Not Applicable

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.

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 40 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Influence of Dexmedetomidine on the Evoked Potentials During Spine Surgery
Study Start Date : February 2008
Actual Primary Completion Date : May 2010
Actual Study Completion Date : May 2010

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
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

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

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 80 Years   (Adult, Older Adult)
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

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): 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, now a wholly owned subsidiary of Pfizer
Principal Investigator: Irene Rozet, MD University of Washington

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 )
First Posted: July 2, 2007    Key Record Dates
Last Update Posted: September 14, 2012
Last Verified: September 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