# Promising novel therapy with hydrogen gas for emergency and critical care medicine.
> 救急・集中治療領域における水素ガスの医療応用に関するレビュー


## Abstract

Hydrogen gas has been reported to exert beneficial effects across a broad spectrum of conditions, ranging from acute disorders such as ischemia-reperfusion injury and hemorrhagic shock to chronic conditions including metabolic syndrome, rheumatoid arthritis, and neurodegenerative diseases. Antioxidant and anti-inflammatory mechanisms have been proposed, yet the precise molecular target of hydrogen gas remains unidentified. This review summarizes findings from research conducted through an industry-academia collaborative center focused on hydrogen medicine, covering areas such as acute myocardial infarction, cardiopulmonary arrest syndrome, contrast-induced acute kidney injury, and hemorrhagic shock within the context of emergency and critical care medicine.

### Mechanism

Hydrogen gas is proposed to act via antioxidant and anti-inflammatory pathways, though its specific molecular target has not yet been identified.

## Bibliographic

- **Authors**: Sano M, Suzuki M, Homma K, Hayashida K, Tamura T, Matsuoka T, et al.
- **Journal**: Acute Med Surg
- **Year**: 2018
- **PMID**: [29657720](https://pubmed.ncbi.nlm.nih.gov/29657720/)
- **DOI**: [10.1002/ams2.320](https://doi.org/10.1002/ams2.320)
- **PMC**: [PMC5891106](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5891106/)
- **Study type**: review
- **Delivery route**: inhalation
- **Effect reported**: not assessed

## Delivery context

For inhalation applications of molecular hydrogen, the lower flammability limit (LFL) deserves careful handling. The classical 4% figure applies to closed-system mixtures; the practical inhalation-environment threshold is 10%. Even pure-hydrogen output (the UFL 75% paradox) passes through the flammable range at the air–gas boundary. High-concentration (66% / 100%) inhalers are documented in the Japanese Consumer Affairs Agency accident-information database and are not recommended.

## Safety notes

For inhalation applications of molecular hydrogen, the lower flammability limit (LFL) deserves careful handling. The classical 4% figure applies to closed-system mixtures; the practical inhalation-environment threshold is 10%. Even pure-hydrogen output (the UFL 75% paradox) passes through the flammable range at the air–gas boundary. High-concentration (66% / 100%) inhalers are documented in the Japanese Consumer Affairs Agency accident-information database and are not recommended.

See also:
- [Inhalation concentration and LFL / UFL](https://h2-papers.org/en/safety-notes/inhalation-concentration)
- [Consumer Affairs Agency accident cases](https://h2-papers.org/en/safety-notes/accident-cases)
- [LFL / UFL terminology](https://h2-papers.org/en/safety-notes/lfl-ufl-explained)
- [Inhalation safety threshold lineage](https://h2-papers.org/en/safety-notes/lineage)

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> **Cite as**: H2 Papers — PMID 29657720. https://h2-papers.org/en/papers/29657720
> **Source**: PubMed PMID [29657720](https://pubmed.ncbi.nlm.nih.gov/29657720/)