Comparative Research Of Hemodynamics Which Is Produced By Interposed Abdominal Compression-CPR With Different Frequency In Canines

Objective : Comparing hemodynamic parameter between IAC-CPR withdifferent frequency and standard-CPR,in order to investigate the bestfrequency of IAC-CPR and the mechanism of hemodynamics which isproduced by IAC-CPR with different frequency.Method:Twelve healthy and mongrel canines were divided into fourgroups,repeatly and randomly.All canines were resuscitated by fourcompression methods including S-CPR,80IAC-CPR,100IAC-CPR,120IAC-CPR,the order of which was determined randomly.Electrocardiogram ofanaesthetized canines were monitored by electrocardiograph;6F pigtailcatheter were placed in the center vein,carotid artery,ascendingaorta;the model of ventricular fibrillation was induced by electricshock in vitro.Five minutes after each compression method was put inpractice ,we measured the center vein pressure(CVP),the aorta pressureduring systole(AOS),the aorta pressure during diastolic(AOD),the carotid artery pressure during systole(CAS),the carotid pressureartery during diastolic(CAD),then calculated the coronary perfusionpressure(CPP),the mean aorta pressure(MAP),the mean carotid arterypressure(CMAP)by formula.The haemodynamic effects of variations inthe compression frequency was evaluated by statistic analysis.Results:The twelve models of ventricular fibrillation were inducedsuccessfully.We had compared different pressure parameters Using Ftest,and significant statistics difference was found(P<0.01).At thesame time,we compared the AOS,AOD,MAP,CMAP,CVP,CPP in each other,whichwere produced by four compression methods.statistics method wasperformed with q test.1)AOS,AOD,MAP:Significant statistics differencewas found in multiple comparison(P<0.05),except group between80IAC-CPR and 120IAC-CPR.The result indicated that 100IAC-CPR wasbetter than other compression methods and S-CPR is the lowest.2)CMAP:significant statistics difference was found with the multiplecomparison ( P<0.05 ) .100IAC-CPR method was the best compressionmethod,8OIAC-CPR was better,S-CPR was the worst.3)CVP:Significantstatistics difference was found in multiple comparison(P<0.05),exceptS-CPR and 120IAC-CPR.100IAC-CPR method was the best,and 80IAC-CPR wasbetter than other two.4)CPP:Significant statistic difference was foundin multiple comparison(P<0.05),except group between 100IAC-CPR and120IAC-CPR.100IAC-CPR and 120IAC-CPR were the best,80IAC-CPR wasbetter.Conclusion:1.100IAC-CPR can produce better hemodynamic effect than80IAC-CPR and 120IAC-CPR,which suggest that 100IAC-CPR method canresult in more successful rate of resuscitation.We recommend that 100per minute compression frequency should be used on practicing IAC-CPRin clinical stage.2.IAC-CPR method can produced better hemodynamiceffect than S-CPR method.We recommend IAC-CPR method should be priorlyused when condition is adequate.