title: H(2) gas improves functional outcome after cardiac arrest to an extent comparable to therapeutic hypothermia in a rat model.
abstract: BACKGROUND
  All clinical and biological manifestations related to postcardiac arrest (CA) syndrome are attributed to ischemia-reperfusion injury in various organs including brain and heart. Molecular hydrogen (H(2)) has potential as a novel antioxidant. This study tested the hypothesis that inhalation of H(2) gas starting at the beginning of cardiopulmonary resuscitation (CPR) could improve the outcome of CA.
  
  
  RESULTS
  Ventricular fibrillation was induced by transcutaneous electrical epicardial stimulation in rats. After 5 minutes of the subsequent CA, rats were randomly assigned to 1 of 4 experimental groups at the beginning of CPR: mechanical ventilation (MV) with 2% N(2) and 98% O(2) under normothermia (37°C), the control group; MV with 2% H(2) and 98% O(2) under normothermia; MV with 2% N(2) and 98% O(2) under therapeutic hypothermia (TH), 33°C; and MV with 2% H(2) and 98% O(2) under TH. Mixed gas inhalation and TH continued until 2 hours after the return of spontaneous circulation (ROSC). H(2) gas inhalation yielded better improvement in survival and neurological deficit score (NDS) after ROSC to an extent comparable to TH. H(2) gas inhalation, but not TH, prevented a rise in left ventricular end-diastolic pressure and increase in serum IL-6 level after ROSC. The salutary impact of H(2) gas was at least partially attributed to the radical-scavenging effects of H(2) gas, because both 8-OHdG- and 4-HNE-positive cardiomyocytes were markedly suppressed by H(2) gas inhalation after ROSC.
  
  
  CONCLUSIONS
  Inhalation of H(2) gas is a favorable strategy to mitigate mortality and functional outcome of post-CA syndrome in a rat model, either alone or in combination with TH.
authors: Department of Emergency and Critical Care Medicine, Keio University, Tokyo, Japan.
authors: Kei
authors: K
authors: Hayashida
authors: Motoaki
authors: M
authors: Sano
authors: Naomi
authors: N
authors: Kamimura
authors: Takashi
authors: T
authors: Yokota
authors: Masaru
authors: M
authors: Suzuki
authors: Yuichiro
authors: Y
authors: Maekawa
authors: Akio
authors: A
authors: Kawamura
authors: Takayuki
authors: T
authors: Abe
authors: Shigeo
authors: S
authors: Ohta
authors: Keiichi
authors: K
authors: Fukuda
authors: Shingo
authors: S
authors: Hori
mesh_terms: D000818:Animals; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D006323:Heart Arrest / Q000628:therapy*; D006859:Hydrogen / Q000008:administration & dosage*; D007036:Hypothermia, Induced / Q000379:methods*; D015850:Interleukin-6; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012121:Respiration, Artificial / Q000379:methods*; D015996:Survival Rate; D014693:Ventricular Fibrillation / Q000628:therapy*
chemical_list: D015850:Interleukin-6; D006859:Hydrogen
keywords: cardiac arrest; cardiopulmonary resuscitation; hydrogen gas; therapeutic hypothermia; ventricular fibrillation