Combination of Hydrogen Inhalation and Hypothermic Temperature Control After Out-of-Hospital Cardiac Arrest: A Post hoc Analysis of the Efficacy of Inhaled Hydrogen on Neurologic Outcome Following Brain Ischemia During PostCardiac Arrest Care II Trial
Tamura T, Narumiya H, Homma K, Suzuki M, Efficacy of Inhaled Hydrogen on Neurologic Outcome Following Brain Ischemia During PostCardiac Arrest Care (HYBRID II) Study Group. · Critical care medicine. 2024;52(10):1567-1576.
What kind of evidence is this?
Human
Randomized controlled study
Cardiovascular and circulatory health
Inhaled H₂
Not reported in this record.
Not reported in this record.
Methods at a glance
Human participants studied for cardiovascular and circulatory health. See eligibility criteria in the linked full text.
Human study; the full text reports 72 participants.
18 hours
Full text reports inhaled H₂-containing gas. Detected intervention quantities or schedules: 2%, 94%, 50%, 18 hours.
Inhaled molecular H₂ at 2%; not classified as Brown’s gas without an H₂/O₂ composition.
H₂-related quantities reported in the intervention passages: 2%, 94%, 50%, 18 hours. Values are not combined across different experimental arms.
Not reported in the full article — an absolute H₂ flow in mL/min could not be verified.
O₂ concentration and absolute O₂ flow were not both reported in the full article; no value is inferred.
Control or comparison condition reported in the full article; see the linked methods for arm-specific details.
Outcomes and reported result
survival or mortality, clinical symptoms or functional scores, inflammation and cytokines, oxidative-stress and antioxidant markers, apoptosis or cell injury, histology or tissue damage
Article-reported result excerpt (24 words maximum): “The adjusted analysis using the generalized estimating equations model showed that a combination of hydrogen and TTM32–TTM34 was associated with a higher rate of…” This excerpt is not a complete result summary; consult the linked full text for all positive and null findings.
The complete machine-readable article was checked for source identity, methods, intervention quantities, results, tables, funding and conflict declarations. This public record is based on the full article.
A reported association, difference or mechanism is not automatically a clinical benefit. Null findings, outcome type, study design and precision all matter.
Cautions and applicability
Human evidence; design, sample size and comparator limit interpretation. No funding statement was identified in the machine-readable full article; absence is not inferred. No explicit conflict statement was identified in the machine-readable full article; absence is not inferred.
Applies only to the population and protocol reported in this cardiovascular and circulatory health article.
Not reported in this record.
Not reported in this record.
Not reported in this record.
No single-study GRADE certainty rating is assigned. Certainty is assessed by important outcome across a complete eligible evidence set, not by attaching a final grade to one source.
Sources and record status
PMID: 39133068 · DOI: 10.1097/ccm.0000000000006395
A free full article is available through PubMed Central.
Official Europe PMC JATS full article and PubMed/PMC identifiers; structured full-text extraction and validation completed 8 August 2026.
2026-08-10