オミクロン株SARS-CoV-2感染回復における水素/酸素吸入の有効性：多施設無作為化対照試験
This multicenter randomized controlled trial enrolled 64 patients with Omicron SARS-CoV-2 infection, randomly allocated to hydrogen/oxygen mixed gas inhalation (n=32) or oxygen-only inhalation (n=32). The hydrogen/oxygen group demonstrated a shorter viral shedding duration compared with the control group. Cumulative negative conversion rates showed a progressive increase from day 3 onward in the hydrogen/oxygen group. IL-6 concentrations declined by 22.8% from baseline, and lymphocyte counts rose to 61.1% of baseline values by day 3 in the hydrogen/oxygen group. A greater proportion of patients in the hydrogen/oxygen group exhibited resolution of pulmonary lesions on imaging. These findings indicate that molecular hydrogen inhalation may support immune recovery and reduce inflammatory markers in COVID-19 patients.
Inhalation of hydrogen/oxygen mixed gas was associated with reduced IL-6 levels and restored lymphocyte counts, suggesting suppression of inflammatory cytokine signaling and enhancement of immune cell recovery, which may have contributed to faster viral clearance and pulmonary lesion resolution.
For inhalation applications of molecular hydrogen, the lower flammability limit (LFL) deserves careful handling. The classical 4% figure applies to closed-system mixtures; the practical inhalation-environment threshold is 10%. Even pure-hydrogen output (the UFL 75% paradox) passes through the flammable range at the air–gas boundary. High-concentration (66% / 100%) inhalers are documented in the Japanese Consumer Affairs Agency accident-information database and are not recommended.
See also:
https://h2-papers.org/en/papers/37970554