The Neural Mechanisms of Anesthesia and Human Consciousness (Part 6)

NCT ID: NCT02624401

Last Updated: 2017-03-27

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

COMPLETED

Clinical Phase

PHASE4

Total Enrollment

160 participants

Study Classification

INTERVENTIONAL

Study Start Date

2016-01-31

Study Completion Date

2017-03-13

Brief Summary

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Positron Emission Tomography (PET), Magnetic Resonance Imaging (MRI) and electroencephalography (EEG) studies will be carried out to reveal the neural correlates of consciousness. Consciousness of the subjects will be manipulated with anesthetic agents dexmedetomidine, propofol, S-ketamine and sevoflurane. One-hundred-and-sixty (160) healthy male subjects will be recruited to receive EC50 concentration of the anesthetic (40 dexmedetomidine, 40 propofol, 20 S-ketamine, 40 sevoflurane) or placebo (20) while being imaged for cerebral metabolic rate of glucose (CMRglu). Also genetic, immunological and metabolomics samples will be taken and analysed to find possible genetic factors explaining the variability in drug response and to find chemical fingerprints of acute drug effect.

Detailed Description

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The explanation of consciousness poses one of the greatest challenges to science and philosophy in the 21st century. It remains unclear what consciousness is and how it emerges from brain activity. Positron Emission Tomography (PET), Magnetic Resonance Imaging (MRI) and electroencephalography (EEG) studies will be carried out to reveal the neural correlates of consciousness. Consciousness of the subjects will be manipulated with anesthetic agents dexmedetomidine acting through α2-agonism, with propofol and sevoflurane both mainly acting through the enhancement of gamma-aminobutyric acid (GABA) system, and with S-ketamine acting through N-methyl-D-aspartate (NMDA) receptor antagonism. One-hundred-and-sixty (160) healthy male subjects will be recruited to receive EC50 concentration of either dexmedetomidine, propofol, S-ketamine or sevoflurane, or placebo while being imaged for cerebral metabolic rate of glucose (CMRglu). 40 subjects will receive dexmedetomidine, 40 subjects propofol, 20 subjects S-ketamine, 40 subjects sevoflurane and 20 subjects will receive placebo. Also genetic, immunological and metabolomics samples will be taken and analysed to find possible genetic factors explaining the variability in drug response and to find possible immunological and chemical fingerprints of acute drug effect.

Conditions

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Anesthesia Unconsciousness

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

BASIC_SCIENCE

Blinding Strategy

NONE

Study Groups

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Dexmedetomidine

Intravenous dexmedetomidine using target controlled infusion.

Group Type EXPERIMENTAL

Dexmedetomidine

Intervention Type DRUG

Intravenous infusion

Propofol

Intravenous propofol using target controlled infusion.

Group Type EXPERIMENTAL

Propofol

Intervention Type DRUG

Intravenous infusion

S-ketamine

Intravenous S-ketamine using target controlled infusion.

Group Type EXPERIMENTAL

S-ketamine

Intervention Type DRUG

Intravenous infusion

Sevoflurane

Inhalational sevoflurane using target controlled inhalation.

Group Type EXPERIMENTAL

Sevoflurane

Intervention Type DRUG

Inhalation

Placebo

Intravenous saline.

Group Type PLACEBO_COMPARATOR

Placebo

Intervention Type DRUG

Intravenous infusion of saline (Ringer's Acetate)

Interventions

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Dexmedetomidine

Intravenous infusion

Intervention Type DRUG

Propofol

Intravenous infusion

Intervention Type DRUG

S-ketamine

Intravenous infusion

Intervention Type DRUG

Sevoflurane

Inhalation

Intervention Type DRUG

Placebo

Intravenous infusion of saline (Ringer's Acetate)

Intervention Type DRUG

Other Intervention Names

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Dexdor Propofol-Lipuro Ketanest-S Sevorane

Eligibility Criteria

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Inclusion Criteria

1. Male
2. Age 18-30 years
3. Good general health i.e. American Society of Anesthesiologists (ASA) physical status I
4. Fluent in Finnish language
5. Right handedness
6. Written informed consent
7. Good sleep quality

Exclusion Criteria

1. Chronic medication
2. History of alcohol and/or drug abuse
3. Strong susceptibility for allergic reactions
4. Serious nausea in connection with previous anesthesia
5. Strong susceptibility for nausea
6. Any use of drugs or alcohol during the 48 hours preceding anesthesia
7. Use of caffeine products 10-12 hours prior the study
8. Smoking
9. Clinically significant previous cardiac arrhythmia / cardiac conduction impairment
10. Clinically significant abnormality in prestudy laboratory tests
11. Positive result in the drug screening test
12. Blood donation within 90 days prior to the study
13. Participation in any medical study with an experimental drug or device during the preceding 60 days
14. The study subject has undergone a prior PET or SPECT study
15. Any contraindication to magnetic resonance imaging (MRI)
16. Hearing impairment
17. Detected unsuitability based on MRI scanning results if available before the PET scanning
18. Sleep disorder or severe sleep problem
Minimum Eligible Age

18 Years

Maximum Eligible Age

30 Years

Eligible Sex

MALE

Accepts Healthy Volunteers

Yes

Sponsors

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University of California, Irvine

OTHER

Sponsor Role collaborator

University of Michigan

OTHER

Sponsor Role collaborator

Yale University

OTHER

Sponsor Role collaborator

University of Helsinki

OTHER

Sponsor Role collaborator

University of Turku

OTHER

Sponsor Role lead

Responsible Party

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Harry Scheinin

Adjunct Professor

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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Harry Scheinin, MD

Role: PRINCIPAL_INVESTIGATOR

Turku PET Centre, University of Turku, Turku, Finland

Locations

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Turku PET Centre

Turku, , Finland

Site Status

Countries

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Finland

References

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Langsjo JW, Alkire MT, Kaskinoro K, Hayama H, Maksimow A, Kaisti KK, Aalto S, Aantaa R, Jaaskelainen SK, Revonsuo A, Scheinin H. Returning from oblivion: imaging the neural core of consciousness. J Neurosci. 2012 Apr 4;32(14):4935-43. doi: 10.1523/JNEUROSCI.4962-11.2012.

Reference Type BACKGROUND
PMID: 22492049 (View on PubMed)

Langsjo JW, Revonsuo A, Scheinin H. Harnessing anesthesia and brain imaging for the study of human consciousness. Curr Pharm Des. 2014;20(26):4211-24.

Reference Type BACKGROUND
PMID: 24025060 (View on PubMed)

Nummela A, Laaksonen L, Scheinin A, Kaisti K, Vahlberg T, Neuvonen M, Valli K, Revonsuo A, Perola M, Niemi M, Scheinin H, Laitio T. Circulating oxylipin and bile acid profiles of dexmedetomidine, propofol, sevoflurane, and S-ketamine: a randomised controlled trial using tandem mass spectrometry. BJA Open. 2022 Dec 12;4:100114. doi: 10.1016/j.bjao.2022.100114. eCollection 2022 Dec.

Reference Type DERIVED
PMID: 37588789 (View on PubMed)

Nummela AJ, Laaksonen LT, Laitio TT, Kallionpaa RE, Langsjo JW, Scheinin JM, Vahlberg TJ, Koskela HT, Aittomaki V, Valli KJ, Revonsuo A, Niemi M, Perola M, Scheinin H. Effects of dexmedetomidine, propofol, sevoflurane and S-ketamine on the human metabolome: A randomised trial using nuclear magnetic resonance spectroscopy. Eur J Anaesthesiol. 2022 Jun 1;39(6):521-532. doi: 10.1097/EJA.0000000000001591. Epub 2021 Sep 22.

Reference Type DERIVED
PMID: 34534172 (View on PubMed)

Laaksonen L, Kallioinen M, Langsjo J, Laitio T, Scheinin A, Scheinin J, Kaisti K, Maksimow A, Kallionpaa RE, Rajala V, Johansson J, Kantonen O, Nyman M, Siren S, Valli K, Revonsuo A, Solin O, Vahlberg T, Alkire M, Scheinin H. Comparative effects of dexmedetomidine, propofol, sevoflurane, and S-ketamine on regional cerebral glucose metabolism in humans: a positron emission tomography study. Br J Anaesth. 2018 Jul;121(1):281-290. doi: 10.1016/j.bja.2018.04.008. Epub 2018 May 8.

Reference Type DERIVED
PMID: 29935583 (View on PubMed)

Other Identifiers

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LOC-2016

Identifier Type: -

Identifier Source: org_study_id

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