濒死呼吸对心脏骤停猪模型冠脉灌注压的影响

Effects of spontaneous agonal respiration on coronary perfusion pressure during untreated cardiac arrest in swine modelL/U

目的探讨心脏骤停（CA）（心室颤动）家猪模型中濒死呼吸对冠状动脉灌注压（CPP）的影响、意义及其可能的机制。方法10头健康雄性家猪，体质量（25．0±1．5）kg。常规麻醉、气管插管。经右股动脉置管至胸主动脉实时监测主动脉压力（AOP）。经右颈外静脉置管至右心房实时监测右心房压力（RAP）。经心内膜交流电刺激诱发心室颤动（VF）致CA。未处理时间8min。采集濒死呼吸前后AOP、RAP计算CPP并进行统计学分析，濒死呼吸前后CPP数值比较采用前后配对t检验。结果所有动物心脏骤停（心室颤动）模型均一次制作成功并出现濒死呼吸。濒死呼吸吸气前1SCPP为（7．18±4．22）mrnHg（1mmHg=0．133kPa）；呼气后0S为（11．78±5．16）mmHg，明显高于濒死呼吸前水平（t=-3．140，P=0．012〈0．05）；呼气后5S为（8．75±4．38）mmHg，与吸气前1S比较明显升高（t=-2．828P=0．020〈0．05）；呼气后6s为（8．23±4．55）mmHg，与吸气前1S比较，差异无统计学意义，t=-1．778P：0．109〉0．05。结论濒死呼吸是心脏骤停的伴随表现，濒死呼吸后CPP升高并持续至呼气末5S有利于心肺复苏。

Objective To investigate the effects of spontaneous agonal respiration on coronary perfusion pressure （CPP） during untreated cardiac arrest （ventricular fibrillation ） in swine model. Methods Ten male healthy domestic swines （25.0 ± 1. 5 ） kg were anaesthetised, intubated and mechanically ventilated. The catheterizations were separately inserted into the fight atrium and thoracic aorta to monitor aortic pressure （AOP） and right atrial pressure （RAP）. A pacing electrode was inserted into the right ventricle to induce ventrieular fibrillation （VF）. VF was induced by intra-ventricular stimulation with alternating electric current and untreated for 8 minutes. AOP and RAP were recorded until respiratory activity ceased. The CPP before and after agonal respiration was calculated and analyzed by paired-sample T test. Results All animals presented with agonal respiration from 1 to 6 minutes after VF during the first attempt. The CPP was （7.18 ±4. 22） mmHg at 1 sec before agonal respiration, （ 11. 78±5. 16） mmHg at 0 sec after agonal respiration, （8.75 ±4. 38） mmHg at 5 sec after agonal respiration and （8.23 ±4. 55） mmHg at 6 sec after agonal respiration. The CPP at 0 see after agonal respiration was higher than that before agonal respiration （t = -3. 140, P = 0. 012）. The CPP at 5 sec after agonal respiration was higher than that at 1 sec before agonal respiration （t = -2. 828, P =0. 020）. There was no difference in CPP between at 6 sec after agonal respiration and at 1 see before agonal respiration （t = - 1. 778, P =0. 109）. Conclusions Agonal respiration accompanies ventricular fibrillation. After agonal respiration, the coronary perfusion pressure is increased for 5 seconds being in favor of eardiaopulmonary resuscitation.