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Synchronous Effect of Anesthetics on fMRI, EEG and Clinical Responses

  • identifier


  • Recruitment Status


  • First Posted

    April 26, 2019

  • Last update posted

    May 6, 2019

Study Description

Brief summary:

Background: The mechanisms of action of intravenous anesthetics are unclear and the current monitors have limitations. This signifies difficulties when assessing the correct dosage due to the considerable inter-individual variability of the patients, particularly in the elderly or seriously ill. It is necessary to customize the administration of anesthetics as underdosage can lead to the patient awareness during aggressive procedures, and over-dosage can cause serious complications and even augment mortality. Objective: To design a new monitoring system of the levels of consciousness and analgesia in anesthetized subjects which is more accurate than those currently employed. It will be based on the synchronic changes of functional magnetic resonance (fMR) and electroencephalograph (EEG) readings, and clinical responses. Methodology: Thirty healthy volunteers will be given propofol and remifentanil in different combinations, and painful stimuli will be also applied. The principal variable will be fMR images obtained by echo-planar imaging sequences. Real time will be correlated with cortical connectivity maps (connectome), EEG parameters (qCON, qNOX), clinical responses, and concentrations of anesthetics measured by pharmacokinetic and pharmacodynamic models (TCI).

  • Condition or Disease:Sedative Overdose
  • Intervention/Treatment: Drug: Propofol
    Drug: Remifentanil
  • Phase: Phase 1/Phase 2

Detailed Description

Main goal: Develop a system for monitoring the effect of anesthetics on consciousness and pain, based on synchronous changes in functional neuroimaging, EEG and clinical responses. Secondary objectives: - Analyze the changes produced in the cortical connectivity map during the induction of anesthesia to understand the process of "advancement". - Know more accurately the neuronal circuits involved in propofol-induced sleep. - Study if the application of a known painful stimulus modifies in any way (clinical, EEG or by RMf) the LOC that has just been reached. - Establish propofol dosing guidelines adjusted to each patient, studying if they reach the LOC at "sedative" or "hypnotic" doses. - Establish remifentanil dosing guidelines, adjusted to each patient, studying the concentration of remifentanil to which the pain response in neuroimaging is inhibited (activation deactivation neuronal in fMRI). - Validate existing mathematical models in relation to plasma and brain concentrations of propofol and remifentanil. - Validate the value of clinical signs to predict whether a patient feels the painful stimulus received.

Study Design

  • Study Type: Interventional
  • Actual Enrollment: 30 participants
  • Intervention Model: Sequential Assignment
  • Intervention Model Description: Volunteers recieving propofol and then remifentanil.
  • Masking: None (Open Label) ()
  • Primary Purpose: Basic Science
  • Official Title: Synchronous Effect of Anesthetics on fMRI, EEG and Clinical Responses. Development of a More Precise System for Monitoring Anesthetic Effect.
  • Actual Study Start Date: September 2016
  • Actual Primary Completion Date: March 2019
  • Actual Study Completion Date: April 2019

Arms and interventions

Arm Intervention/treatment
Experimental: Volunteers recibing propofol and remifentanil
Volunteers receive propofol to the loss of consciousness. Then they receive remifentanil during 12 min (pain stimuli in their finger also)
Drug: Propofol

Drug: Remifentanil

Outcome Measures

  • Primary Outcome Measures: 1. Time and dose of propofol at loss of conciousness (LOC) [ Time Frame: 10-15 min ]
    Volunteers stop tightening pneumatic pear. We register time and dose of propofol when the volunteer stops tightening pneumatic pear.
  • 2. Register EEG and neuroimage during remifentanil administration. [ Time Frame: 10-15 min ]
    After LOC, volunteers receive increasing doses of remifentanil and painful stimuli in the nail bed. If apnea, stop infusion remifentanil Volunteers receive increasing doses of remifentanil and painful stimuli in the nail bed. If apnea, stop infusion remifentanil. We registered time, dose, saturation and breathing frecuency in every volunteer.

Eligibility Criteria

  • Ages Eligible for Study: 18 to 50 Years (Adult)
  • Sexes Eligible for Study: All
  • Accepts Healthy Volunteers: Yes


Inclusion Criteria:

- Healthy adult volunteers (ASA 1 physical state) who agree to participate voluntarily
in the study, previous information about it by the Principal Investigators (IP).

Exclusion Criteria:

- Psychological, psychiatric or neurological disorders. Consumption of drugs.
Alterations cutaneous or anatomical cranial. Idiomatic or communication barrier.
Allergy to propofol, remifentanil or to some of its excipients. Body mass index (BMI)
30 kg / m2. Pregnancy. Airway or ventilation criteria hard. Absence of
accompanying adult at the end of the study.

Contacts and Locations



Sponsors and Collaborators

Parc de Salut Mar

More Information

  • Other Publications

    Borrat X, Ubre M, Risco R, Gambús PL, Pedroso A, Iglesias A, Fernandez-Esparrach G, Ginés À, Balust J, Martínez-Palli G. Computerized tests to evaluate recovery of cognitive function after deep sedation with propofol and remifentanil for colonoscopy. J Clin Monit Comput. 2019 Feb;33(1):107-113. doi: 10.1007/s10877-018-0134-3. Epub 2018 Mar 27.

  • Responsible Party: Parc de Salut Mar
  • Identifier: NCT03928366 History of Changes
  • Other Study ID Numbers: UNLOCK
  • First Posted: April 26, 2019 Key Record Dates
  • Last Update Posted: May 6, 2019
  • Last Verified: April 2019
  • Individual Participant
    Data (IPD) Sharing

  • Plan to Share IPD: Yes
  • Plan Description: Participants will be introduced to the fMRI The head will be set to try to prevent involuntary movements associated with the LOC. Routine by pulse oximetry, non-invasive blood pressure (NIBP) and electrocardiogram (ECG). It will be administered oxygen at 2 liters / min by nasal cannula with capnography line and transcutaneous CO2 will be monitored. Volunteers will not be premedicated. EEG activity and fMRI images, as detailed in the section "Study variables". Each series of acquisitions will consist of a "resting state" (rs-fMRI), in which the subject will be asked to close their eyes and leave the mind ramble without further slogans, and also a series of tasks in which the participant will be exposed to a sequence of perceptive and nociceptive stimuli in order to objectify the effect of the drug on the nervous system central. The BOLD signal extracted from the RMf images will allow to study the dynamics of the metabolic changes and neurons in the brain with a temporal resolution.
  • Supporting Materials: Study Protocol
  • Time Frame: 3 years
  • Access Criteria: volunteers without exclusion criteria
  • Studies a U.S. FDA-regulated Drug Product: No
  • Studies a U.S. FDA-regulated Device Product: No
  • Keywords provided by Parc de Salut Mar: Propofol, remifentanil, hypnosis, EEG, fMRI,
  • Additional relevant MeSH terms: Drug Overdose