Effects Of Hygrogen Inhalation On Post-resuscitation Cardiac And Cerebral Function In An Asphyxial Cardiac Arrest Model Of Rats

Non-shockable rhythms represent an increasing proportion of reported cases of out-of-hospital cardiac arrest but with an associated poor prognosis.Hydrogen has profound neuroprotective effects and could significantly improve survival in ventricular fibrillation model of cardiac arrest.However,the effectiveness of this therapeutic approach in non-shockable rhythms is still undetermined.Methods and Main results:??Establish the myocardial damage and neurological damage disease model of cardiac arrest caused by asphyxia,to explore the effects of 2% hydrogen inhalation on cardiac and neurological function after cardiopulmonary resuscitation and compared the therapeutic benefit with hypothermia.Cardiopulmonary resuscitation was initiated after 5 minutes of untreated asphyxial cardiac arrest in 72 Sprague-Dawley rats.Animals were randomly assigned to three experimental groups immediately following successful resuscitation: ventilation with 2% hydrogen/98% oxygen under normothermia(H2),ventilation with 2% nitrogen/98% oxygen under normothermia(control)and ventilation with 2% nitrogen/98% oxygen under hypothermia(TH).Mixed gas inhalation continued for 1 hour while hypothermia continued for 2 hours.Animals were monitored in an intensive care setting for 4 hours following return of spontaneous circulation and observed up to 96 hours for assessment of survival as well as neurologic recovery.Analysis of ultrasound data in each group of rats at different time points were set up.The myocardial injury c Tn T and brain injury s-100 B were indicated by ELISA at different time points.No statistical differences in the baseline measurements were observed among groups and all the animals were successfully resuscitated.Serum level of cardiac troponin T and S100 B measured during earlier post-resuscitation period were remarkably lower in both H2 and TH groups.However,significantly better left ventricular ejection fraction and neurological deficit score were observed in the H2 group.Ninety-six hours survival rate was 75.0% in the H2(p=0.004 vs.control and p=0.039 vs.TH),45.8% in the TH(p=0.376 vs.control)and 33.3% in the control group.??Preliminarily study the heart and brain protection mechanism of hydrogen inhalation after asphyxia cardiac arrest.36 healthy SD rats were randomly divided into three groups:(1)Sham group: only anesthesia,intubation and surgical blood vessels cannula;(2)Control group: after resuscitation,ventilation with 2% nitrogen/98% oxygen under normothermia,observing 4 hours;(3)Experimental groups: after resuscitation,ventilation with 2% hydrogen/98% oxygen under normothermia,observing 4 hours.All animals were sacrificed at endpoint toexplore blood biochemistry and pathology biochemical indicators.Compared with the control group,the serum inflammatory factors IL-6,IL-8,IgG and apoptosis factor TFAR19 were significantly reduced after resuscitation four hours in the experimental group,the difference was statistically significant(p <0.05).Conclusion: In this asphyxial rat model of cardiac arrest and resuscitation,inhaling small amounts of hydrogen was superior to mild hypothermia in improving neurological outcome and survival.The protective effect of hydrogen was related to its anti-inflammatory and anti-apoptotic reactions.