Multivariate Analysis In Factors Influencing The Early Survival After Resuscitation Of Asphyxial Cardiac Arrest In Rats

ObjectiveTo establish the model of asphyxial cardiac arrest in rats;compare of differences in vital signs and physicochemical indexes after resuscitation 24h between survival group vs death group.To investigate and analyze the related factors affecting the early survival in rats after recovery,to provide the basis for early evaluation and prediction of the prognosis of resuscitation for cardiac arrest.MethodsThe model of cardiac arrest?CA?in rats was made by asphyxia.Adult healthy 3-4month,weight 250-420g,SPF class Sprague-Dawley male rats were selected.Tracheal intubation was conducted under direct vision after anesthesia.One side femoral artery by incision and catheterization connected with the pressure transducer,monitoring blood pressure;the other side of the femoral vein catheterized to open venous access.Rats were suffocated by clamping the endotracheal intubation at the end of expiration.The definition of CA in rats was systolic blood pressure?SBP?less than 25 mmHg.TO carry out CPR after CA 5min without intervention,and give intravenous injection of epinephrine?E?/sodium bicarbonate?SB?.Restoration Of Spontaneous Circulation?ROSC?was defined as the average arterial pressure?MAP??60mmHg,and the duration sustained at least 10min.Chest compressions more than 20min without spontaneous circulation recovery considered as resuscitation failure.During the recovery process,all parameters were monitored and recorded.Observe and record the weight of rats;heart rate?HR?,mean arterial pressure?MAP?before recovery;respiratory arrest time,cardiac arrest time and duration of resuscitation;the frequency of E/SB use;rhythm of initial recovery?ventricular fibrillation/pulseless ventricular tachycardia,pulseless electrical activity,ventricular asystole?;HR,MAP and arterial blood gas analysis results after ROSC 30min.Comparing the observation indexes between survival group and death group after cardiopulmonary resuscitation?CPR?24h in asphyxial cardiac arrest rats,to analyze and explore the related factors that might affect the early survival rate after resuscitation.ResultsA total of 72 rats were involved in the experiment,and 33 rats successfully resuscitated were included in the study.The critical point was 24 hours,and there were 20rats in the survival group and 13 rats in the death group.Compared with baseline data of rats before CA,there was no significant difference in weight,HR,MAP,pH,PaO₂,PaCO₂,Lac,HCO₃^—and TCO₂ between the two groups?P>0.05?.Among the recovery related indicators,the duration of resuscitation?s?in the survival group was significantly shorter than that in the death group,and the difference was statistically significant?83.65±39.97 vs 173.08±70.43,p=0.001?;Epinephrine/Sodium bicarbonate used in the survival group was significantly less than the death group,there was statistical difference between the two groups?1.20±0.52 vs 2.0±1.23,p=0.042?.The respiratory arrest time,cardiac arrest time were not significant difference between the two groups?p>0.05?.In the indicators after resuscitation,HR,MAP recorded after ROSC 30min were not significant difference between the two groups?p>0.05?.Comparison of blood gas analysis after ROSC 30 min between the two groups,pH value of the survival group was significantly higher than that of death group,there was statistical difference between the two groups?7.24±0.07 vs 7.15±0.06,p=0.001?;lactic acid?Lac,mmol/L?of the survival group was statistically significantly decreased than death group?3.91±1.67 vs 5.43±1.09,p=0.007?;Actual bicarbonate?HCO₃^—,mmol/L?of the survival group was higher than the value of death group,there was statistical difference between groups?18.98±2.60 vs15.66±4.03,p=0.007?.Total carbon dioxide?TCO₂,mmol/L?of the survival group was higher than the value of death group,there was statistical difference between groups?20.44±2.68 vs 17.99±2.61,p=0.017?.Comparison of arterial oxygen partial pressure?PaO₂?,arterial partial pressure of carbon dioxide?PaCO₂?,serum sodium?Na?,serum potassium?K?,serum calcium?Ga?,blood glucose?Glu?,hematocrit?Hct?,hemoglobin?Hb?etc.between the two groups after recovery,the differences were not statistically significant?p>0.05?The survival after resuscitation 24h in rats was considered as the dependent variable,and the index after screening with statistical differences,such as the duration of resuscitation,PH,Lac,HCO₃^—,TCO₂ and the frequency of E/SB use were considered as independent variables.Using the regression analysis by Logistic with all variable model,the duration of resuscitation was independent risk factors for early survival after recovery in rats?OR=1.058,95%CI 1.010-1.107,p=0.016?.Conclusion:The experimental study by animal model suggest that the duration of resuscitation is an independent risk factor for early survival after resuscitation in asphyxiated rats.In addition,the frequency of epinephrine/sodium bicarbonate use,the status of acidosis after resuscitation and level of lactic acid are also important factors that affect the early survival in rats.