Hydrogen Inhalation is Superior to Mild Hypothermia in Improving Cardiac Function and Neurological Outcome in an Asphyxial Cardiac Arrest Model of Rats.

Abstract

Using a rat model of asphyxial cardiac arrest, this study compared three post-resuscitation interventions: inhalation of 2% H2 in oxygen for 1 hour, mild hypothermia maintained for 2 hours, and a normothermic control. Serum cardiac troponin T and S100B levels declined in both the H2 and hypothermia groups relative to controls. However, left ventricular ejection fraction, cardiac work index, and neurological deficit scores were significantly more favorable in the H2 inhalation group than in either comparator. The 96-hour survival rate reached 75.0% with H2 inhalation, compared with 45.8% under hypothermia and 33.3% in controls; no statistically significant difference was detected between the hypothermia and control groups. These findings indicate that brief H2 inhalation following cardiopulmonary resuscitation confers greater cardioprotective and neuroprotective benefit than mild hypothermia in this experimental setting.

Mechanism

Inhalation of 2% H2 reduced serum markers of myocardial injury (troponin T) and brain damage (S100B) after resuscitation, suggesting that selective scavenging of reactive oxygen species underlies the observed cardioprotective and neuroprotective effects.