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Detection of Consciousness by EEG and Auditory Evoked Potentials

This study has been completed.
Information provided by (Responsible Party):
Gerhard Schneider, Technische Universität München Identifier:
First received: October 29, 2012
Last updated: October 31, 2012
Last verified: October 2012
The objective of the present investigation is to analyze EEG and auditory evoked potentials at the transition from consciousness to unconsciousness and vice versa. A set of electroencephalographic and auditory evoked potential parameters should be identified that allows separation of consciousness from unconsciousness (reflected by responsiveness/unresponsiveness to command). The study is based on data of 80 patients undergoing general anesthesia with remifentanil and either sevoflurane or propofol.

Condition Intervention Phase
Electroencephalography/ Drug Effect
Drug: Propofol / Remifentanil
Drug: Sevoflurane / Remifentanil
Phase 4

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Diagnostic
Official Title: Detection of Consciousness by EEG and Auditory Evoked Potentials

Resource links provided by NLM:

Further study details as provided by Technische Universität München:

Primary Outcome Measures:
  • Changes in EEG- and AEP-parameters during loss- and return of consciousness [ Time Frame: 1 day ]

Secondary Outcome Measures:
  • Impact of muscle activity on EEG- and AEP-parameters [ Time Frame: 1 day ]
  • Influence of anesthetics on EEG- and AEP-parameters [ Time Frame: 1 day ]

Enrollment: 80
Study Start Date: January 2001
Study Completion Date: April 2003
Primary Completion Date: November 2001 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
No Intervention: Propofol or Sevoflurane
General anesthesia
Drug: Propofol / Remifentanil
General anesthesia: Loss of consciousness and standard clinical practice
Drug: Sevoflurane / Remifentanil
General anesthesia: Loss of consciousness and standard clinical practice

Detailed Description:
During the past years, monitoring of anesthetic effects on the main target of anesthesia, the brain, has gained increasing attention. Monitoring of the spontaneous electroencephalogram (EEG) and of auditory evoked potentials (AEP) has been suggested. Even if EEG and AEP reflect effects of anesthetic drugs, a visual interpretation is not expedient. As a consequence, several processing methods have been suggested that reduce the electroencephalogram to a numerical value. In the current study, a set of EEG- and AEP parameters based on different analysis methods is tested with respect to the parameters ability in separating consciousness (reflected by responsiveness to command) from unconsciousness at the transition between these stages. Therefore data of 80 unpremedicated patients undergoing general anesthesia with remifentanil and either sevoflurane or propofol is used. The study period is from induction of anesthesia until patients follow command after surgery and includes a reduction of the hypnotic agent after tracheal intubation until patients follow command. The isolated forearm technique is applied before muscle relaxants are given to maintain the ability to squeeze hand to command.

Ages Eligible for Study:   Child, Adult, Senior
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • American Society of Anesthesiologists (ASA) physical status 1-2
  • Adult patients

Exclusion Criteria:

  • Patients with contraindications to the study drugs
  • psychiatric or neurologic disease
  • drug abuse or medication known to affect the central nervous system
  • pregnancy
  • indication for rapid sequence induction
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Please refer to this study by its identifier: NCT01720615

Technische Universität München, Klinikum rechts der Isar, Department of Anesthesiology
Munich, Bavaria, Germany
Sponsors and Collaborators
Technische Universität München
Study Chair: Eberhard F Kochs, MD Klinikum rechts der Isar, Technische Universität München
  More Information

Responsible Party: Gerhard Schneider, Dr. med., Technische Universität München Identifier: NCT01720615     History of Changes
Other Study ID Numbers: 2001
Study First Received: October 29, 2012
Last Updated: October 31, 2012

Keywords provided by Technische Universität München:
General anesthesia

Additional relevant MeSH terms:
Central Nervous System Depressants
Physiological Effects of Drugs
Hypnotics and Sedatives
Anesthetics, Intravenous
Anesthetics, General
Analgesics, Opioid
Sensory System Agents
Peripheral Nervous System Agents
Platelet Aggregation Inhibitors
Anesthetics, Inhalation processed this record on April 28, 2017