| CHAPTER 1 THE EFFECT OF DIFFERENT OXYGEN INHALATION TIME ON THE PROGNOSIS OF NERVE FUNCTION AFTER CARDIOPULMONARY RESUCITATION IN ASPHYXIA RATSObjective:To study the effect of different oxygen inhalation time at room temperature on the prognosis of neurological function after resuscitation of cardiac arrest induced by ventricular fibrillation in rats.Methods:32 SD male rats were resuscitated to induce cardiac arrest after 6 minutes of cardiopulmonary arrest.The animal model of cardiopulmonary resuscitation was established.According to the different oxygen inhalation time,the rats were randomly divided into 4 groups?n=8?after cardiopulmonary resuscitation.Oxygen 0 minute group?O2-0min?,oxygen inhalation 20 minute group?O2-20min?,oxygen inhalation 60minute group?O2-60min?,oxygen inhalation 180 minute group?O2-180min?.The changes of hemodynamics and cardiac function,nervous system damage score?NDS?and survival rate after resuscitation were compared.Enzyme-linked immunosorbent assay was used to measure the basal state,serum tissue protein cTnT and S-100?content 6 hours after recovery.Results:The average arterial pressure and left ventricular ejection fraction of the O2-180min group were significantly higher than those of the O2-0min group?P<0.05?;the EEG recovery time of the O2-180min group was significantly shorter than that of the O2-0min group.In the O2-180min group,brain tissue and myocardial injury were significantly lower than that in the O2-0min group 6 hours after resuscitation?S-100?,P<0.01;cTnT,P<0.05?.The neurological deficit score and survival rate in the O2-180min group were significantly improved compared with the O2-0min group.Conclusion:After cardiopulmonary resuscitation induced by asphyxia in SD rats,prolonged oxygen inhalation to 3 hours can significantly improve the prognosis of heart and nervous system function and improve survival rate.CHAPTER 2 STUDY ON THE PROTECTIVE MECHANISM OF HYDROGEN COMBINED WEITH OXYGEN AT DIFFERENT CONCENTRATIONS IN THE BRAIN AFTER CARDIAC ARRESTObjective: To study the effect of hydrogen combined with different concentrations of oxygen at room temperature on the prognosis of neurological damage after ventricular fibrillation-induced cardiac arrest in rats.Methods: 64 male SD rats were started cardiopulmonary resuscitation7 minutes after ventricular fibrillation induced cardiac arrest,and an animal model of brain injury after ventricular fibrillation cardiopulmonary resuscitation was established.After successful resuscitation,the experimental animals were randomly divided into 4 groups?n = 16?:control group?21% O2?,2% hydrogen + 21% oxygen group?2% H2 + 21%O2?,2 % Hydrogen + 50% oxygen group?2% H2 + 50% O2?and 2%hydrogen + 98% oxygen group?2% H2 + 98% O2?,each group inhaled the corresponding mixed gas for 3 hours.Hemodynamics and cardiac function changes 6 hours after resuscitation,arterial blood gas 3 hours and 6 hours after resuscitation,EEG,NDS scores and survival rates after resuscitation were compared.The basic condition was measured by enzyme-linked immunosorbent assay,3 hours and 6 hours after recovery: the content of superoxide dehydrogenase 1?SOD1?and reduced glutathione?GSH?.HE staining,Csapses3 immunofluorescence staining,and Tunel staining were used to observe the morphological changes of hippocampus in rats after 96 hours of survival.25 male SD rats with ventricular fibrillation induced cardiac arrest were recovered after 7 minutes,and animal models of brain injury after ventricular fibrillation?n = 5?were established: Sham group,21% O2 group,2% H2 + 21% O2 group,2% H2 + 50% O2 group and 2% H2 + 98% O2 group.After successful modeling,the corresponding gas was inhaled for 3hours,and the Sham group was used as the blank control group.After 6hours of resuscitation,they were sacrificed,and the content of SOD1,MDA,8-OHDG in brain tissue homogenate was measured by ELSE method.Results: 3 hours after resuscitation,the arterial oxygen partial pressure in the 2% H2 + 50% O2 group and the 2% H2 + 98% O2 group was significantly higher than that in the control group?P <0.05?,EEG burst suppression wave,continuous background EEG appearance time Significantly ahead of time,HE staining,Tunel staining of hippocampal necrotic apoptotic cells 2% H2 + 50% O2 group and 2% H2 + 98% O2 group were significantly lower than the control group,survival rate was significantly higher than the control group?P <0.05?.Six hours after resuscitation,SOD1 in brain tissue homogenate of 2%H2 + 50% O2 group and 2% H2 + 98% O2 group was significantly higher than that of control group?P <0.05?.The MDA in the 2% H2 + 50% O2 group and the 2% H2 + 98% O2 group was significantly lower than that in the control group?P <0.05?.The 8-OHDG in the 2% H2 + 98% O2 group was significantly higher than that in the control group and the 2% H2 +21% O2 group?P <0.05?.Conclusion: At room temperature,2% hydrogen combined with 50%oxygen,2% hydrogen combined with 98% oxygen for 3 hours can significantly improve the survival rate of ventricular fibrillation-induced cardiopulmonary resuscitation,and reduce the necrosis and apoptosis of hippocampal tissue cells.Hydrogen can reduce the brain tissue damage after cardiopulmonary resuscitation by enhancing the antioxidant effect of brain tissue and improve the prognosis of nerve function. |
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