NCT07263399

Effect of Hydrogen Gas on Hyperbaric Oxygen Toxicity

Effect of Hydrogen Gas on Hyperbaric Oxygen Toxicity - A Randomized Controlled Cross-Over Trial

• Status: Not Yet Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 32 (estimated)
• Sponsor: Blekinge Institute of Technology · Academic / Other
• Sex: All
• Age: 20 Years – 64 Years
• Healthy volunteers: Accepted

Summary

The goal of this trial is to investigate whether adding a small fraction of hydrogen gas to an oxygen-enriched breathing mixture can reduce pulmonary oxygen toxicity (POT) in healthy and active divers from the Swedish Armed Forces. The main questions it aims to answer are: * Does hydrogen gas reduce oxidative stress and changes in pulmonary function associated with prolonged hyperbaric oxygen exposure? * What are the underlying pathophysiological mechanisms of pulmonary oxygen toxicity? Researchers will compare oxygen-enriched breathing gas with 1-2% hydrogen to oxygen-enriched gas with 1-2% nitrogen (control) to see if hydrogen provides protective effects against POT during hyperbaric exposure. Participants will: * Complete two hyperbaric exposure sessions (hydrogen vs. nitrogen), each lasting 240 minutes at 1.75 ATA * Undergo pulmonary function tests and sampling of blod and urin before and after each session * Serve as their own controls in a double-blind, randomized, crossover study design

Conditions

• Oxygen Toxicity
• Oxidative Stress
• Hyperoxia
• Hyperbaric Oxygen
• Healthy Subjects (HS)
• Diving Medicine
• Hydrogen-oxygen Gas

Interventions

Type	Name	Description
OTHER	Inhaled Hydrogen-Enriched Oxygen Gas	Participants will inhale a gas mixture consisting of 98-99% oxygen and 1-2% hydrogen via a breathing circuit during a single hyperbaric exposure. The exposure will be conducted at a partial pressure of 1.75 ATA for 240 minutes. The intervention aims to evaluate the protective effect of hydrogen gas against pulmonary oxygen toxicity.
OTHER	Inhaled Nitrogen-Enriched Oxygen Gas	Participants will inhale a gas mixture consisting of 98-99% oxygen and 1-2% nitrogen via a breathing circuit during a single hyperbaric exposure. The exposure will be conducted at a partial pressure of 1.75 ATA for 240 minutes. The intervention aims to evaluate the protective effect of hydrogen gas against pulmonary oxygen toxicity.

Timeline

• Start date: 2026-01-01
• Primary completion: 2029-12-01
• Completion: 2030-12-01
• First posted: 2025-12-04
• Last updated: 2025-12-04

Locations

2 sites across 1 country: Sweden