Nitrous Oxide in Blood, Breath, and Urine After Different Exposures
Official title: Undersøgelse af Lattergaskoncentrationer i Blod, udåndingsluft og Urin Ved Forskellige Eksponeringer
Run by University of Aarhus · NCT07690358 · Data updated 2026-11-12
This study tests how nitrous oxide appears in blood, breath, and urine after three different exposures in adults.
Quick facts
| Study type | Interventional |
|---|---|
| Ages | 18 Years to 65 Years |
| Sex | All |
| Enrollment | 40 (estimated) |
| Sponsor | University of Aarhus Academic / other |
| Drugs / interventions | methotrexate |
| Locations | 1 site (Aarhus) |
| Status | Recruiting |
| Started | June 1, 2026 |
| Main results expected | December 31, 2026 |
| Study ends | December 31, 2026 |
| Registry record updated | July 8, 2026 |
| Trial ID | NCT07690358 on ClinicalTrials.gov |
Is this trial a fit for you?
✓Likely a good fit
Adults aged 18-65 who understand Danish, are willing to use contraception for 24 hours after exposure, and can provide informed consent.
✕Probably not a fit
Individuals with recent nitrous oxide use, substance use disorders, or significant medical conditions may not benefit from participation.
A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.
What this trial studies
Healthy adults are exposed to nitrous oxide in three ways: car cabin exposure with several cartridges, use of whipped cream propellant, and occupational exposure as a midwife. Concentrations in blood and urine are measured for up to 2 hours, and breath levels are tracked for up to 1 hour using gas chromatography, mass spectrometry, and an optical sensor. The study aims to characterize how quickly N2O appears and clears from each biospecimen under these exposure scenarios. Exclusion criteria limit participation to adults without recent nitrous oxide use or relevant health issues.
Why it matters
Potential benefit: If successful, the results could improve understanding of how nitrous oxide distributes in the body after common exposure scenarios, aiding forensic interpretation and safety guidelines.
How similar studies have gone: Previous work has demonstrated measurable N2O levels in biological samples; this study builds on that approach but with three distinct exposure types.
Who can join: the full rules
Show full inclusion / exclusion criteria
For arm 1, 2, and 3: Inclusion Criteria: * Age 18-65 years * Able to understand Danish * Willing to use effective contraception for 24 hours after the end of exposure (oral contraceptives, contraceptive implant, transdermal patch, vaginal ring, or injectable contraceptives) * Written informed consent Exclusion Criteria: * Current or past abuse of drugs, nitrous oxide (N₂O), or alcohol * A psychiatric disorder requiring medical treatment, including severe depression * A diagnosis of epilepsy * Symptoms of peripheral neuropathy * Significant cardiac or pulmonary disease * Previous allergic or adverse reaction to N₂O * Diving within the past 2 days * Inability to refrain from diving for 2 days after the study * Occupational exposure to N₂O * Use of N₂O within the past 3 months * Treatment with methotrexate, benzodiazepines, opioids, or other centrally depressant drugs * Recent intraocular gas injection * Known impaired liver or kidney function * Pregnant or breastfeeding women (fertile women, defined as amenorrhea for less than 12 months, must have a negative hCG pregnancy test prior to receiving the study intervention)
Where it's running
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Department of Forensic Medicine
Aarhus, Denmark Recruiting
Study contacts
- Study coordinator: Charlotte U Andersen, Associate Professor
- Email: cua@biomed.au.dk
- Phone: +4560128430
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How to take part
- Review the eligibility criteria above with your treating physician.
- Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
- Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.