Association between hydrogen gas inhalation and cardiac output in an asphyxiated piglet model
Sakamoto K, Nakamura S, Tsuchiya T, Mitsuie T, Nakao Y, Htun Y, Yokota T, Inoue K, Inoue E, Wakabayashi T, Morimoto A, Koyano K, Konishi Y, Iwase T, Horii T, Kusaka T. · Scientific Reports. 2026;16:4344.
What kind of evidence is this?
Preclinical
Randomized two-group newborn-piglet hypoxic-ischemic resuscitation experiment
Critical care and ischemia-reperfusion
Other forms
Not reported in this record.
Not reported in this record.
Methods at a glance
Piglets no older than 24 hours subjected to approximately 40 minutes of controlled hypoxic-ischemic insult and resuscitation.
17 piglets randomized after resuscitation: hypoxic-ischemic control n=10 and H₂ inhalation n=7; cardiac-troponin analysis was available for 9 and 4 animals, respectively.
Six hours after hypoxic-ischemic insult and resuscitation.
Mechanically ventilated H₂ for six hours beginning after resuscitation; concentration varied from 2.1% to 2.7% according to each animal's oxygen requirement.
H₂ alone supplied from a 3.8% H₂/96.2% N₂ cylinder and mixed separately with 100% O₂ — not Brown's gas or oxyhydrogen.
Delivered H₂ 2.1–2.7%; FiO₂ varied from 0.21 to 0.40. Concentrations were adjusted through two gas sources and H₂ was monitored, but absolute total flow was not stated.
Not reported in mL/min — concentration and ventilator settings were provided without an absolute minute-flow value.
O₂ was supplied separately to achieve FiO₂ 0.21–0.40; absolute O₂ flow in mL/min was not reported.
The same hypoxic-ischemic insult and mechanical ventilation without H₂ therapy.
Outcomes and reported result
Serial left/right stroke volume and cardiac output, RV outflow velocity-time integral, blood pressure/heart rate/blood gases and cardiac troponin T.
Right-ventricular cardiac-output area under the curve and the five-hour value favored H₂; six-hour troponin T was lower in the small available subset. Left cardiac output, pulmonary-artery acceleration time, blood gases and several time-point comparisons did not differ significantly.
The complete free PMC article, figures, methods and disclosures were checked for randomization, variable H₂/O₂ composition, missing absolute flows, positive and null cardiac findings, reduced troponin sample, funding and conflicts.
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
Very small neonatal-piglet experiment, unequal groups, short follow-up, anesthesia/ventilation confounding, possible unmeasured shunts, many serial comparisons and troponin available for only four H₂ animals. Japanese public/university grants funded the study; authors declared no competing interests.
Experimental neonatal asphyxia in piglets; it does not establish cardiovascular or neurologic treatment in human newborns.
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: 41530398 · DOI: 10.1038/s41598-026-35115-2
Free full article in PubMed Central.
Complete PMC article and PubMed metadata; full-text extraction checked 9 August 2026.
2026-08-10