Effects Of Distal Abdominal Aorta Occlusion In Vitro On Resuscitation In The Swine Model Of Ventricular Fibrillation Cardiac Arrest And The Location Value Of Umbilicus

Objective To explore the effectiveness of distal abdominal aorta occlusion in vitro assisting in conventional cardiopulmonary resuscitation(CPR)in the swine model of ventricular fibrillation cardiac arrest and the value of umbilicus in locating distal abdominal aorta blocking.Methods(1)Eighteen tibet miniature pigs were equally divided into two groups:conventional CPR group(C-CPR)and distal abdominal aorta occlusion in vitro assisting in conventional CPR group(DAAO-CPR).Ventricular fibrillation(VF)was made through transcutaneous electrical induction(TCEI)with three 9V batteries supplying direct current 3s and lasted for 4min before CPR.C-CPR was performed with chest compression and manually ventilating,on this basis distal abdominal aorta blockage was implemented in DAAO-CPR.At the same time of C-CPR,the distal abdominal aorta blocking device was placed at 0.5cm beyond the left border of the umbilicus,then adjust the compression head to block the abdominal aorta.Hemodynamic changes during CPR and serum indexes such as cTnI within 6h after ROSC were dynamically monitored,also the time and the rate of ROSC,72-hour survival rates were recorded.The apoptosis in myocardiac cells of resuscitated swines were assayed by TUNEL.Finally,the brain functions were evaluated through CPC.(2)Measurements were taken of the cephalocaudal relationship of aortic bifurcation relative to umbilicus and iliac crest vertex and other related anatomic parameters in 108 consecutive abdominal CT scans.Results(1)During CPR,all the hemodynamic indexes of the two groups showed a gradual increase trend except CVP.SBP of C-CPR group at 30,60 and 120 seconds were significantly lower than that of DAAO-CPR group(P<0.05).,Also DBP in C-CPR group were significantly lower than that of DAAO-CPR group for all time points(P<0.05).Compared to C-CPR group,MAP in DAAO-CPR group were significantly higher at 30,60,120,150 and 180 seconds(P<0.05).No significant difference was found between the two groups in CVP(P>0.05).CPP in C-CPR group were significantly lower than that of DAAO-CPR group at 60,90,120,150,180 seconds(P<0.05).Compared with C-CPR group,the successful recovery rate and 72-hour survival rate in DAAO-CPR group were increased,but no significant difference were observed.The level of cTnI in DAAO-CPR group were lower than that in C-CPR during CPR(P<0.05).The CPC of DAAO-CPR group was also lower than those of C-CPR group after 24h of resuscitation.(2)Umbilicus relative to aortic bifurcation was located cephalad in 62.0%and iliac crest vertex was located caudal in 65.7%.Above the aortic bifurcation,the vertical distance of umbilicus to aortic bifurcation(BU)was longer than that from Iliac crest vertex to aortic bifurcation(BC)(P<0.05).No statistically significant relationship was found between BU and BC below the aortic bifurcation.Conclusions(1)In the early recovery of CA in swine,distal abdominal aorta blocking in vitro assisting in conventional cardiopulmonary resuscitation in the swine model of cardiac arrest can improve hemodynamic parameters such as MAP,CPP and serum indexes such as cTnl.It can also shorten the time necessary for ROSC and alleviate the damage in brain function.(2)Umbilicus lie mostly cephalad to aortic bifurcation,which as the body surface makers can completely block blood and was an important landmark of locating abdominal aortic terminal occlusion position in vitro.