Concentrations of Nitrous Oxide in Blood, Exhaled Air and Urine After Various Types of Exposure.

July 7, 2026 updated by: University of Aarhus

Undersøgelse af Lattergaskoncentrationer i Blod, udåndingsluft og Urin Ved Forskellige Eksponeringer

The study examines the concentrations of nitrous oxide that are achieved in blood, exhaled air, and urine after three different exposures to nitrous oxide:

inhalation of three or four cartridges of nitrous oxide released in a car cabin in a switched-off car, consumption of 100 g of whipped cream in which nitrous oxide is used as a propellant, and exposure through work as a midwife in a delivery room.

The concentrations in blood and exhaled air are measured for up to 1 hour after exposure, and in urine for up to 2 hours after exposure. The concentrations in blood and urine are measued with gas chromatography and mass spectrometry, while the concentration in exhaled air is measured by a sensor using an NDIR sensor (Olythe, France).

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

40

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

  • Name: Charlotte U Andersen, Associate Professor
  • Phone Number: +4560128430
  • Email: cua@biomed.au.dk

Study Locations

  • Denmark
      • Aarhus, Denmark, 8200
        • Recruiting
        • Department of Forensic Medicine
        • Contact:
          • Charlotte U Andersen, Associate Professor
          • Phone Number: +4560128430
          • Email: cua@biomed.au.dk

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

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)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Passive exposure in car, 3 cartridges
A person sits for 15 minutes after releasing 4 x 8.4 g of nitrous oxide into the cabin
Other: Nitrous Oxide 99 %
Passive exposure to Nitrous Oxide
Experimental: Passive exposure in car, 4 cartridges
A person sits for 15 minutes after releasing 4 x 8.4 g of nitrous oxide into the cabin
Other: Nitrous Oxide 99 %
Passive exposure to Nitrous Oxide
Experimental: Whipped cream, 100 g
A person ingests 100 g of whipped cream with nitrous oxide as propellant
Other: Nitrous Oxide 99 %
Passive exposure to Nitrous Oxide
Active Comparator: Environmental exposure
concentrations of nitrous oxide are measured after exposure through work as a midwife in a delivery room
Other: Nitrous Oxide + Oxygen Gas
Midwifes are exposed through work in a delivery room

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Detection time of Nitrous Oxide in blood
Time Frame: From end of exposure to 1 hour after end of exposure
The time after exposure in which Nitrous Oxide can be detected in blood
From end of exposure to 1 hour after end of exposure

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Aarhus

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 1, 2026

Primary Completion (Estimated)

December 31, 2026

Study Completion (Estimated)

December 31, 2026

Study Registration Dates

First Submitted

June 29, 2026

First Submitted That Met QC Criteria

July 7, 2026

First Posted (Actual)

July 8, 2026

Study Record Updates

Last Update Posted (Actual)

July 8, 2026

Last Update Submitted That Met QC Criteria

July 7, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 1-10-72-156-25

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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