Hydrogen Gas Improves Brain Recovery After Cardiac Arrest in Rats
Hydrogen Inhalation During Normoxic Resuscitation Improves Neurological Outcome in a Rat Model of Cardiac Arrest Independently of Targeted Temperature Management
Research hubs: Cardiovascular System · Brain & Nervous System
This research was done in animals. Results in animals often don't carry over to people.
- Evidence type
- Animal study (rat)
- Authors
- Kei Hayashida, Motoaki Sano, Naomi Kamimura, Takashi Yokota, Masaru Suzuki, Shigeo Ohta, Keiichi Fukuda, Shingo Hori
- Journal
- Circulation
- Year
- 2014
- PMID
- 25366995
- Study Type
- Rat
- Delivery
- Gas
- Dose
- 1.3% H2 inhalation begun 5 minutes after return of spontaneous circulation, continued during mechanical ventilation
- H₂ concentration
- 1.3% H2
- Duration
- 1 weeks
- Outcome
- Positive
- Peer Reviewed
- Yes
- Cited by
- 126 (OpenAlex, as of November 2026)
- Country
- Japan
TL;DR
Starting hydrogen gas inhalation right after a rat's heart starts beating again, with or without cooling therapy, improves survival and brain health after cardiac arrest.
Key Finding
Rats that received both hydrogen inhalation and targeted cooling therapy after cardiac arrest had an 85.7% survival rate at 7 days, compared to 38.4% in untreated controls, with the combined treatment showing superior neurological recovery compared to cooling alone.
Summary
Researchers studied whether inhaling hydrogen gas could help rats recover from cardiac arrest (when the heart stops beating). After the rats' hearts restarted, some received hydrogen gas mixed with their breathing air, some received cooling therapy (a standard treatment), some received both, and some received neither. Rats that received both hydrogen and cooling therapy had the best survival rates and the least brain damage, suggesting that hydrogen gas may enhance recovery when added to existing cardiac arrest treatments.
Practical Takeaway
This rat study suggests hydrogen gas may have neuroprotective potential as an add-on to standard cardiac arrest treatment, but these results cannot yet be applied to humans. Human clinical trials would be needed to determine if this approach is safe and effective in cardiac arrest patients.
Abstract (excerpt)
Background— We have previously shown that hydrogen (H 2 ) inhalation, begun at the start of hyperoxic cardiopulmonary resuscitation, significantly improves brain and cardiac function in a rat model of cardiac arrest. Here, we examine the effectiveness of this therapeutic approach when H 2…