Assessing Covert Consciousness in Unresponsive Patients

NCT ID: NCT02659228

Last Updated: 2016-10-27

Basic Information

• Recruitment Status: UNKNOWN
• Clinical Phase: NA
• Total Enrollment: 60 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2016-12-31

Brief Summary

In this study, the investigators explore anesthesia as a tool for providing further insight into the level of consciousness of individuals with a clinical diagnosis of unresponsive wakefulness syndrome (UWS), but who possess some neurophysiological signatures of conscious awareness. This group, who could potentially be conscious, will herein be referred to as the target population. Our goal is to assess whether or not neurological patterns of consciousness in the target population respond to anesthesia in a similar manner to neurologically compromised individuals with known consciousness (e.g. those in minimally conscious state (MCS). In healthy controls, propofol-induced unconsciousness results in an elimination of the mismatch negativity event-related brain potential (ERP) and a diminished directed connectivity. The investigators hypothesize that at doses well below those required for surgery, anesthesia will have similar effects on these neural patterns in neurologically compromised patients with the potential for conscious awareness, but will not affect these patterns in those who lack consciousness.

Conditions

Consciousness Disorders

Study Design

• Allocation Method: NON_RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

Control 1 (negative control)

Individuals with a diagnosis of UWS without neural markers of consciousness

Group Type: PLACEBO_COMPARATOR

EEG recording

Intervention Type: DEVICE

EEG recording with anesthetic (DIPRIVAN)

Control 2 (positive control)

Individuals with a diagnosis of MCS, who are behaviourally responsive and who present neural markers of consciousness

Group Type: ACTIVE_COMPARATOR

EEG recording

Intervention Type: DEVICE

EEG recording with anesthetic (DIPRIVAN)

Target Population

Individuals with a clinical diagnosis of UWS, but who possess some neurophysiological signatures of conscious awareness

Group Type: EXPERIMENTAL

EEG recording

Intervention Type: DEVICE

EEG recording with anesthetic (DIPRIVAN)

Anesthetics, Intravenous

Intervention Type: DRUG

The participant will receive an intravenous infusion of propofol (DIPRIVAN Injectable Emulsion USP 1%, AstraZeneca).

Interventions

EEG recording

EEG recording with anesthetic (DIPRIVAN)

Intervention Type: DEVICE

Anesthetics, Intravenous

The participant will receive an intravenous infusion of propofol (DIPRIVAN Injectable Emulsion USP 1%, AstraZeneca).

Intervention Type: DRUG

Eligibility Criteria

Inclusion Criteria

• Patients admitted to the intensive care unit at Hamilton General Hospital who:

• Clinical status consistent with UWS (no responsiveness to commands)
• Clinical status consistent with MCS (minimal response to at least one command)
• Presence of an endotracheal tube (ETT) or a tracheostomy tube
• Between 18 and 50 years of age

Exclusion Criteria

• • Elevated intracranial pressure (ICP)

• Hepatic or renal failure
• Hemodynamic instability
• Active vasopressor therapy
• Previous open-head injury
• Previous intracranial pathology requiring neurosurgical interventions in the past 72 hours
• Anticipated ICU stay < 24 hours
• Documented allergy to propofol
• Pregnancy
• BMI > 35 kg/m2
• Anyone who is deemed medically unsuitable for this study by the attending intensivist
• Patients who are already in a medically-induced coma for intracranial hypertension or status epilepticus

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 50 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

McGill University

OTHER

Sponsor Role: collaborator

McMaster University

OTHER

Sponsor Role: collaborator

University of Michigan

OTHER

Sponsor Role: lead

Responsible Party

George Mashour

Bert N La De Professor of Anesthesiology Research

Responsibility Role: PRINCIPAL_INVESTIGATOR

Other Identifiers

13-784

Identifier Type: -

Identifier Source: org_study_id