NCT02624401

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

• Status: Completed
• Phase: Phase 4
• Study type: Interventional
• Enrollment: 160 (actual)
• Sponsor: University of Turku · Academic / Other
• Sex: Male
• Age: 18 Years – 30 Years
• Healthy volunteers: Accepted

Summary

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

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

• Anesthesia
• Unconsciousness

Interventions

Type	Name	Description
DRUG	Dexmedetomidine	Intravenous infusion
DRUG	Propofol	Intravenous infusion
DRUG	S-ketamine	Intravenous infusion
DRUG	Sevoflurane	Inhalation
DRUG	Placebo	Intravenous infusion of saline (Ringer's Acetate)

Timeline

• Start date: 2016-01-01
• Primary completion: 2017-03-13
• Completion: 2017-03-13
• First posted: 2015-12-08
• Last updated: 2017-03-27

Locations

1 site across 1 country: Finland