# Inhalation of molecular hydrogen prevents ischemia-reperfusion liver damage during major liver resection.
> 大規模肝切除術における分子状水素吸入による虚血再灌流肝障害の予防


## Abstract

This animal study examined the antioxidant, anti-inflammatory, and anti-apoptotic potential of inhaled molecular hydrogen during major liver resection in a domestic pig model. Twelve pigs were divided equally into a hydrogen inhalation group and a conventional anesthesia control group. Warm ischemia was maintained for 120 minutes, followed by 120 minutes of reperfusion. Histological assessment using the Suzuki scoring system revealed statistically significant reductions in hepatic damage in the hydrogen group. Among biochemical markers, gamma-glutamyl-transferase (GMT) showed a statistically significant difference between groups, while hepatic transaminases, alkaline phosphatase, lactate dehydrogenase, and lactate did not differ significantly. Plasma oxidative damage markers varied considerably between groups. The findings indicate that hydrogen inhalation during major hepatic surgery reduces ischemia-reperfusion-associated oxidative stress, supported by both histological and direct biochemical evidence.

### Mechanism

Inhaled H2 is thought to scavenge reactive oxygen species generated during ischemia-reperfusion, thereby reducing oxidative stress, inflammatory signaling, and apoptotic cell death in hepatic tissue.

## Bibliographic

- **Authors**: Malý O, Zajak J, Hyšpler R, Turek Z, Astapenko D, Jun D, et al.
- **Journal**: Ann Transl Med
- **Year**: 2019
- **PMID**: [32042790](https://pubmed.ncbi.nlm.nih.gov/32042790/)
- **DOI**: [10.21037/atm.2019.11.43](https://doi.org/10.21037/atm.2019.11.43)
- **PMC**: [PMC6989999](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6989999/)
- **Study type**: animal study
- **Delivery route**: inhalation
- **Effect reported**: positive

## 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)

---

> **Cite as**: H2 Papers — PMID 32042790. https://h2-papers.org/en/papers/32042790
> **Source**: PubMed PMID [32042790](https://pubmed.ncbi.nlm.nih.gov/32042790/)