Effect of Nitrous Oxide on EEG

Study Overview
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Brief Summary
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Our recent preclinical observations suggest that monitoring of slow electroencephalogram (EEG) oscillations may be used to predict the efficacy of rapid-acting antidepressants such as ketamine or nitrous oxide. In this project we will carry out critical clinical research on healthy volunteers and study the effects of nitrous oxide on EEG. Results will be used for the design of clinical trials on depressed individuals. The project will be done in collaboration between neuroscientists at the University of Helsinki and clinicians at the Tampere University Hospital.

Official Title
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The Effect of Nitrous Oxide on EEG, a Randomized, Double-blinded Study

Conditions
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Nitrous Oxide, Electroencephalography, Anesthetic, Inhalation

Intervention / Treatment
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* Drug: Nitrous Oxide


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: informed consent obtained age between 18 - 40 male body mass index 18 - 27 Exclusion Criteria: Age < 18 or > 40 Alcohol Use Disorders Identification Test (AUDIT) >6 points Drug Abuse Screening Test 20 (DAST-20) > 0 points Beck Depression Inventory (BDI) > 11 points Symptom Check List 90 (SCL-90) over mean values of Finnish population in any dimensions of the SCL-90 or the global severity index Any respiratory disorder including sleep apnea Any heart illness Epilepsy Known vitamin B12 deficiency

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Intermittent nitrous oxide<br>10 minutes of 50% nitrous oxide + 10 min 100% oxygen + 10 min 50% nitrous oxide + 10 min 100% oxygen | Drug: Nitrous Oxide<br>* 50% nitrous oxide<br>|
| Experimental: Continuous nitrous oxide<br>20 min 50% nitrous oxide + 20 min 100% oxygen | Drug: Nitrous Oxide<br>* 50% nitrous oxide<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Slow wave activity | Delta wave in EEG | During nitrous oxide administration | 
| Slow wave activity | Delta wave in EEG | Following 20 minutes after nitrous oxide administration | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Self-reported psychiatric symptoms | Symptom Check List 90 (SCL-90) is a self-reported questionnaire measuring psychological stress. Results are normed, meaning that test scores can be compared to Finnish reference values. In this study we measure if there is an increase in self-reported psychiatric symptoms after nitrous oxide administration. | Baseline, 20 minutes after nitrous oxide | 
| Side effects - anxiety | Self reported anxiety on a 0 (no at all) to 5 (very much) scale | Baseline, 20 minutes after nitrous oxide | 
| Side effects - restlessness | Self reported restlessness on a 0 (no at all) to 5 (very much) scale | Baseline, 20 minutes after nitrous oxide | 
| Side effects - mood elevation | Self reported mood elevation on a 0 (no at all) to 5 (very much) scale | Baseline, 20 minutes after nitrous oxide | 
| Side effects - nausea | Self reported nausea on a 0 (no at all) to 5 (very much) scale | Baseline, 20 minutes after nitrous oxide | 
| Side effects - tension | Self reported tension on a 0 (no at all) to 5 (very much) scale | Baseline, 20 minutes after nitrous oxide | 
| Side effects - uneasiness | Self reported uneasiness on a 0 (no at all) to 5 (very much) scale | Baseline, 20 minutes after nitrous oxide | 
| Side effects - tiredness | Self reported tiredness on a 0 (no at all) to 5 (very much) scale | Baseline, 20 minutes after nitrous oxide | 
| Side effects - numbness | Self reported numbness on a 0 (no at all) to 5 (very much) scale | Baseline, 20 minutes after nitrous oxide | 
| Side effects - dizziness | Self reported dizziness on a 0 (no at all) to 5 (very much) scale | Baseline, 20 minutes after nitrous oxide | 
| Side effects - agitation | Self reported agitation on a 0 (no at all) to 5 (very much) scale | Baseline, 20 minutes after nitrous oxide | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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EEG, Slow wave activity, Nitrous oxide, N-methyl-D-aspartate-receptor blockade, Delta wave, Self-reported psychiatric symptoms