心停止ラットモデルにおける常酸素条件下の蘇生時水素吸入が標的体温管理とは独立して神経学的転帰を改善する
This study investigated the efficacy of 1.3% H2 inhalation initiated after return of spontaneous circulation (ROSC) under normoxic conditions in a rat ventricular fibrillation cardiac arrest model. Following 6 minutes of cardiac arrest and cardiopulmonary resuscitation, animals were randomized 5 minutes post-ROSC into four groups: normothermia control (26% O2), H2 inhalation (26% O2 + 1.3% H2), targeted temperature management (TTM), and combined TTM plus H2. Seven-day survival rates were 38.4% (control), 71.4% (H2 and TTM groups), and 85.7% (TTM+H2). Neurological deficit scores at 24, 48, and 72 hours post-ROSC and motor activity at 7 days were superior in the combined group compared with TTM alone. Neuronal degeneration and microglial activation in vulnerable brain regions were suppressed by both individual interventions, with the combination yielding the greatest effect. H2 inhalation provided benefit even without hyperoxic conditions.
H2 inhalation suppresses neuronal degeneration and microglial activation in vulnerable brain regions following cardiac arrest; combined with targeted temperature management, these neuroprotective effects are further enhanced.
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/25366995