Induction of Dreaming With EEG and Anesthesia in Healthy Adults

Official title

Comparison of Ketamine Versus Saline During Sedation in Patients With Major Depressive Disorder: a Double-blind Trial

Overview

This open-label, randomized crossover study in healthy adults tests two propofol protocols to produce distinct experiential states. One induces brief loss of responsiveness with spontaneous emergence, intended to elicit dream reports; the other maintains light sedation without loss of responsiveness, intended to elicit non-dream experiences while participants remain responsive. The main goals are to (a) measure the protocol-concordant experiential report rate (how often each method produces its intended experience), (b) explore EEG correlates of these experiences in the two states, and (c) describe their phenomenology (what they are like). We will also examine short-term changes in well-being and sleep related to these experiences. Participants complete four sessions (two of each method) with EEG and routine monitoring, immediate post-session interviews, and brief questionnaires and daily sleep/dream logs before and after anesthesia sessions.

Interventions

• Drug Propofol - Emergence-from-LOR Protocol
  Intravenous propofol infusion that meets the criteria: (1) maintenance of spontaneous ventilation, (2) sedation level corresponding to a Patient State Index (PSI) no lower than 25; and (3) loss of responsiveness (LOR) defined by the Richmond Agitation Sedation Scale (RASS) = -5 \[unarousable\]. Anesthesia is then maintained at that level for 30 minutes, followed by spontaneous emergence.
• Drug Propofol - Light Sedation Protocol
  Intravenous propofol infusion titrated stepwise to reach a state where participants are sedated but have behavioral responsiveness. Sedation is maintained at this level for 30 minutes.

Primary outcome measures

• Protocol-concordant experiential report [Time frame: Assessed within 5 minutes of return of responsiveness (LOR protocol) or within 5 minutes of session end (light-sedation protocol).]

Secondary outcome measures (12)

• EEG correlates of protocol-concordant experiential outcome [Time frame: Matched-duration EEG windows during the 30-minute maintenance period: pre-emergence window prior to return of responsiveness in the LOR protocol, and a time-matched window during maintenance in the no-LOR protocol.]
• Phenomenology of anesthesia experiences (analysis of narrative reports) [Time frame: Interview immediately post-session]
• Phenomenology of anesthesia experiences (self-ratings) [Time frame: Interview immediately post-session]
• Dream vs dream-like experiences (within-anesthesia) - phenomenological differences [Time frame: Interview immediately post-session]
• Home dreams vs anesthesia dreams - phenomenological differences [Time frame: Home dream logs (2 weeks pre-session and 2 weeks post-session) vs anesthesia interview (immediate post-session).]
• Safety outcomes [Time frame: From pre-anesthesia baseline to post-anesthesia discharge]
• Changes in daily mood [Time frame: Baseline (2-week pre-session average) to follow-up (2-week post-session average)]
• Change in well-being: life satisfaction [Time frame: Baseline (2-weeks pre-anesthesia) to follow-up (2-weeks post-anesthesia)]
• Change in well-being: peace of mind [Time frame: Baseline (2-weeks pre-anesthesia) to follow-up (2-weeks post-anesthesia)]
• Change in sleep quality [Time frame: Baseline (2-week pre-session) to follow-up (2-week post-session)]
• Change in dream outcomes [Time frame: Baseline (2-week pre-session) to follow-up (2-week post-session).]
• Change in well-being: harmony in life [Time frame: Baseline (2-weeks pre-anesthesia) to follow-up (2-weeks post-anesthesia)]

Eligibility criteria

Inclusion criteria

• Male or female, 18 to 70 years of age, inclusive, at screen.
• Able to read, understand, and provide written, dated informed consent prior to screening. Participants will be deemed likely to comply with study protocol and communicate with study personnel about adverse events and other clinically important information.
• In sufficiently good health to proceed with a low risk elective procedure, characterized using the American Society of Anesthesiologists (ASA) physical status classification system as Class 1 or 2.
• If female, a status of non-childbearing potential or use of an acceptable form of birth control
• Body mass index between 17-35 kg/m2.

Exclusion criteria

• Female of childbearing potential who is not willing to use one of the specified forms of birth control during the study.
• Female that is pregnant or breastfeeding.
• Female with a positive pregnancy test at screening or baseline.
• Current diagnosis of a Substance Use Disorder (SUD; Abuse or Dependence, as defined by DSM-V) rated "moderate" or "severe", or Alcohol Use Disorder rated "moderate" or "severe". The following categories of SUD will NOT be excluded: nicotine dependence; alcohol or substance use disorder rated "mild"; alcohol or substance use disorder of any severity in remission, either early (3-12 months) or sustained (>12 months) time frames.
• Current diagnosis of Axis I disorders other than Dysthymic Disorder, Generalized Anxiety Disorder, Social Anxiety Disorder, Panic Disorder, Agoraphobia, Specific Phobia, or Bipolar II Disorder
• History of schizophrenia or schizoaffective disorders, or any history of psychotic symptoms
• History of anorexia nervosa, bulimia nervosa, or eating disorder not otherwise specified, within five years of screening.
• In the judgment of the investigator, the subject is at significant risk for suicidal behavior during the course of his/her participation in the study.
• A neurological disorder including:

• Has dementia, delirium, amnestic, or any other cognitive disorder.
• Lifetime history of surgical procedures involving the brain or meninges,
• encephalitis, meningitis, degenerative central nervous system disorder (e.g., Alzheimer's or Parkinson's Disease), epilepsy, mental retardation
• any other disease/procedure/accident/intervention associated with significant injury to or malfunction of the central nervous system (CNS),
• history of significant head trauma within the past two years.
• A cardiovascular disorder including:

• uncontrolled hypertension
• Congestive heart failure NYHA Criteria >Stage 2
• Atrial fibrillation or resting heart rate <50 or >105 beats per minute at screening or randomization
• Any conduction abnormalities including AV nodal block of any type or intraventricular conduction delay.
• QTcF (Fridericia-corrected) >= 450 msec at screening or randomization
• any cardiovascular disorder that would merit categorization of patient as ASA Class 3 or higher
• A pulmonary/respiratory disorder including:

• diagnosed Obstructive Sleep Apnea or STOPBANG score of 3 or higher
• History of difficult airway in surgical setting
• any pulmonary / respiratory disorder that would merit categorization of patient as ASA Class 3 or higher
• Clinically significant liver disease, determined by LFTs within the past 6 months.
• Clinically significant kidney disease determined by creatinine / GFR within the past 6 months.
• Symptomatic gastroesophageal reflux disease, hiatal hernia, or other gastrointestinal disorder placing patient at risk for aspiration or that would merit categorization of patient as ASA Class 3 or higher
• Any endocrine disorder including:

• uncontrolled diabetes, type 1 or 2
• History of hypothyroidism and has been on a stable dosage of thyroid replacement medication for less than six months prior to screening. (Subjects on a stable dosage of thyroid replacement medication for at least six months or more prior to screening are eligible for enrollment.)
• History of hyperthyroidism which was treated (medically or surgically) less than six months prior to screening.
• Other endocrine disorder that would merit categorization of patient as ASA Class 3 or higher
• Patients taking any of the following daily medications:

• opioids including buprenorphine and methadone
• naltrexone or other opioid antagonist
• clonidine
• Any other clinically significant abnormal laboratory result at the time of the screening exam.
• Has a clinically significant abnormality on the screening physical examination that might affect safety, study participation or confound interpretation of study results, including any condition that would merit categorization of patient as ASA Class 3 or higher.
• Participation in any clinical trial with an investigational drug or device that conflicts with this trial, within the past month or concurrent to study participation.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Randomized

Model

Crossover

Masking

Open label

Primary purpose

Basic science

Study locations

United States · 1 center

• Stanford University — Stanford

Publications

• Chow HS, Hack LM, Kawai M, Heifets BD. Anesthetic-Induced Intraoperative Dream Associated With Remission of a Psychiatric Disorder: A Case Report. A A Pract. 2022 Aug 10;16(8):e01613. doi: 10.1213/XAA.0000000000001613. eCollection 2022 Aug 1. PMID 35952341
• Hack LM, Sikka P, Zhou K, Kawai M, Chow HS, Heifets B. Reduction in Trauma-Related Symptoms After Anesthetic-Induced Intra-Operative Dreaming. Am J Psychiatry. 2024 Jun 1;181(6):563-564. doi: 10.1176/appi.ajp.20230698. Epub 2024 Mar 13. No abstract available. PMID 38476046

Identifiers

NCT: NCT07198711 · 55215

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗