Hydrogen gas inhalation alleviates oxidative stress in patients with post-cardiac arrest syndrome
Tamura T et al. · J Clin Biochem Nutr. 2020;67(2):214–221.
What kind of evidence is this?
Human
Single-center open-label single-arm prospective substudy
Critical care and ischemia-reperfusion
Other forms
Not reported in this record.
Not reported in this record.
Methods at a glance
Comatose adults after non-traumatic out-of-hospital cardiac arrest receiving targeted temperature management
5 participants: 4 cardiogenic arrests and 1 septic arrest
18 hours
2% H₂ delivered through a ventilator with titrated oxygen from ICU admission
H₂ added to ventilator gas with clinically titrated O₂ — not Brown’s gas.
2% H₂ by volume; inspired oxygen was titrated clinically.
Not reported — ventilator minute flow varied and no absolute H₂ flow was stated.
O₂ was co-delivered and titrated to clinical need; no single mL/min O₂ value applies or was reported.
No concurrent control group
Outcomes and reported result
Arterial H₂, plasma and urine oxidative-stress markers, IL-6 and TNF-α
Markers varied among the five patients. The authors explicitly judged the effect on oxidative stress and cytokines indefinite because of methodological weaknesses.
Methods, full results, funding and conflicts checked in the free full text; independent appraisal remains incomplete.
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
Only five patients, no control group, heterogeneous arrest causes and simultaneous targeted temperature management. Several authors received research funding from the gas supplier Taiyo Nippon Sanso.
Comatose post-cardiac-arrest patients receiving intensive-care ventilation and targeted temperature management.
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: 33041520 · DOI: 10.3164/jcbn.19-101
Open-access full text is available through PMC.
Open-access PMC full text and PubMed bibliographic record.
2026-08-10