Table 2.

Neuroprotective effects of molecular hydrogen in clinical post-ischemic brain injury.

Ischemia	Number of Participants	Treatment	Benefits	Study	References
Focal	50 patients	Inhalation 3% hydrogen gas (1 h twice a day) for initial 7 days.	Reduced infarct size, improved neurological outcome and daily living activity.	Randomized	[16]
Global	5 patients	2% hydrogen with oxygen was supplied via a respirator after admission to the intensive care unit for 18 h.	4 patients survived 90 days with a favorable neurological outcome.	Pilot study	[25]
Global	360 patients	2% hydrogen with 24 to 50% oxygen was supplied via mechanical ventilation after admission for 18 h.	The first multicenter randomized trial is underway to confirm the efficacy of hydrogen on neurological outcomes in comatose out-of-hospital cardiac arrest survivors.	Randomized, double-blind, placebo-controlled trial.	[26]
Global	5 patients	Inhalation 2% hydrogen with titrated oxygen was initiated upon admission for 18 h.	Oxidative stress markers were reduced in cardiogenic post-cardiac arrest patients but were slightly elevated in the patient with sepsis. Inflammatory cytokine levels remained unchanged in cardiogenic post-cardiac arrest patients, whereas a dramatic reduction was observed in one patient with sepsis.	Pilot study	[27]