经股静—动脉心肺转流术心肺脑复苏机制的探讨

Study on mechanisms of cardiopulmonary bypass through the femoral vein and artery in cardiopulmony-cerebral resuscitation after cardiac arrest in dogs

目的 观察犬电击致室颤 /心跳骤停 (VF/CA) 8min后经开胸心肺复苏 (CPR)和 /或经股静—动脉心肺转流(CPB)心肺复苏对心脏复苏和脑脊液 (CSF)内乳酸 (LA)含量的影响。方法 采用犬经胸壁电击VF/CA 8min ,经CPR恢复自主循环 (RSC)后观察 4h内CSF内LA含量的变化。 9只犬分为两组 ,Ⅰ组 (n =5 )采用开胸心脏按压等方法复苏 ,Ⅱ组 (n =4)于开胸心脏按压同时经一侧股静、动脉心肺转流 ,并维持 2h。结果 Ⅱ组RSC时间较Ⅰ组显著缩短 (6 3± 2 1minvs 13 6± 5 9min ,P <0 0 5 ) ;Ⅱ组CPB后室颤波幅较Ⅰ组明显提高 ;Ⅰ组RSC后 30、6 0、12 0和 2 40minCSF内LA含量均较CA前明显升高(10 7± 3 3、8 8± 3 8、7 8± 3 5、5 6± 1 0vs 3 2± 1 0 ,P均 <0 0 5 ) ,而Ⅱ组RSC后除 30min外各时点CSF内LA含量均较CA前无明显升高 (4 1± 2 6、3 9± 2 4、2 6± 1 7vs 3 0± 0 4,P均 >0 0 5 ) ,且明显低于Ⅰ组各值 (P均 <0 0 5 )。结论 CA后经开胸CPR辅以CPB能提高心脏复苏的有效性 ,抑制单一开胸CPR后发生的CSF内LA含量升高 ,提示其能减轻脑内糖无氧代谢 ,改善脑氧供需关系 。

Objective To study the effects of open chest cardiac massage cardiopulmonary resuscitation(CPR) and/or cardiopulmonary bypass(CPB)through the femoral vein and artery on cardiac resuscitation and the lactate(LA) contents in cerebrospinal fluid(CSF) in dog models with 8 minutes of ventricular fibrillation/cardiac arrest(VF/CA).Methods 9 dogs were divided into two groups.Resuscitation was conducted by using open chest cardiac massage CPR in groupⅠ(n=5) and by using cardiopulmonary bypass(CPB) through unilateral femoral vein and artery at the beginning of open chest cardiac massage CPR in groupⅡ(n=4).Parameters during CPR were recorded and LA contents in CSF were determined before VF/CA and 30 min,60 min,120 min,240 min after return of spontaneous circulation(RSC).Results During cardiac resuscitation,the time to RSC in groupⅡwas shorter significantly than those in groupⅠ(6 3±2 1 min vs 13 6±5 9 min, P <0 05) and the amplitude of ventricular fibrillation (VF) increased after CPB in groupⅡ.In groupⅠ,LA contents in CSF at 30,60,120 and 240 min after RSC increased significantly as compared to baseline(10 7±3 3,8 8±3 8,7 8±3 5,5 6±1 0 vs 3 2±1 0, P <0 05).In groupⅡ,LA contents except 30 min did not increased significantly(4 1±2 6,3 9±2 4,2 6±1 7 vs 3 0±0 4, P >0 05) and was significantly less than those in groupⅠ( P <0 05).Conclusions Resuscitation after CA by using open chest cardiac massage CPR plus CPB may make cardiac resuscitation easier and decrease LA contents in CSF,thus benefiting postarrest brain resuscitation.