Paradis N A
Division of Emergency Medicine, University of Colorado Health Sciences Center, Denver, CO 80262, USA.
Ann Emerg Med. 1999 Dec;34(6):697-702. doi: 10.1016/s0196-0644(99)70093-4.
Occlusion of the descending aorta and infusion of oxygenated ultrapurified polymerized bovine hemoglobin may improve the efficacy of advanced cardiac life support (ACLS). Because selective aortic perfusion and oxygenation (SAPO) directly increases coronary perfusion pressure, exogenous epinephrine may not be required. The purpose of this study was to determine whether exogenous epinephrine is necessary during SAPO by comparing the rate of return of spontaneous circulation and aortic and coronary perfusion pressures during ACLS-SAPO in animals treated with either intra-aortic epinephrine or saline solution.
A prospective, randomized, interventional before-after trial with a canine model of ventricular fibrillation cardiac arrest and ACLS based on external chest compression was performed. The ECG, right atrial, aortic arch, and esophageal pulse pressures were measured continuously. A descending aortic occlusion balloon catheter was placed through the femoral artery. Ventricular fibrillation was induced, and no therapy was given during the 10-minute arrest time. Basic life support was then initiated and normalized by standardization of esophageal pulse pressure and central aortic blood gases. After 3 minutes of basic life support, the aortic occlusion balloon was inflated, and 0.01 mg/kg epinephrine or saline solution was administered through the aortic catheter followed by 450 mL of ultrapurified polymerized bovine hemoglobin over 2 minutes. Defibrillation was then attempted. The outcomes and changes in intravascular pressures were compared.
Aortic pressures were higher during infusions in animals treated with epinephrine. During infusion, the mean aortic relaxation pressure increased by 58+/-5 mm Hg in animals that had received epinephrine versus 20+/-11 mm Hg in those that had received saline placebo. The coronary perfusion pressure during infusion increased by 52+/-8 mm Hg in animals that had received epinephrine versus 26+/-10 mm Hg in those that had received saline. Only 2 of 7 animals in the placebo group had return of spontaneous circulation versus 7 of 8 in the epinephrine group.
The addition of epinephrine to ACLS-SAPO increases vital organ perfusion pressures and improves outcome from cardiac arrest. There appears to be a profound loss of arterial vasomotor tone after prolonged arrest. This loss of vasomotor tone may make exogenous pressors necessary for resuscitation after prolonged cardiac arrest.
降主动脉闭塞并输注氧合超纯聚合牛血红蛋白可能会提高高级心脏生命支持（ACLS）的疗效。由于选择性主动脉灌注和氧合（SAPO）可直接增加冠状动脉灌注压，可能无需使用外源性肾上腺素。本研究的目的是通过比较主动脉内注射肾上腺素或生理盐水的动物在ACLS-SAPO期间自主循环恢复率以及主动脉和冠状动脉灌注压，来确定SAPO期间外源性肾上腺素是否必要。
采用前瞻性、随机、干预前后试验，以基于胸外按压的犬心室颤动心脏骤停和ACLS模型进行研究。连续测量心电图、右心房、主动脉弓和食管脉压。通过股动脉放置降主动脉闭塞球囊导管。诱发心室颤动，在10分钟的停搏时间内不进行任何治疗。然后启动基础生命支持，并通过食管脉压和中心主动脉血气标准化使其正常化。基础生命支持3分钟后，充盈主动脉闭塞球囊，通过主动脉导管给予0.01mg/kg肾上腺素或生理盐水，随后在2分钟内输注450mL超纯聚合牛血红蛋白。然后尝试除颤。比较血管内压力的结果和变化。
接受肾上腺素治疗的动物在输注期间主动脉压力更高。输注期间，接受肾上腺素的动物平均主动脉舒张压力增加58±5mmHg，而接受生理盐水安慰剂的动物为20±11mmHg。接受肾上腺素的动物输注期间冠状动脉灌注压增加52±8mmHg，而接受生理盐水的动物为26±10mmHg。安慰剂组7只动物中只有2只恢复自主循环，而肾上腺素组8只中有7只。
在ACLS-SAPO中添加肾上腺素可增加重要器官灌注压并改善心脏骤停的结局。长时间停搏后动脉血管运动张力似乎有严重丧失。这种血管运动张力丧失可能使外源性升压药对于长时间心脏骤停后的复苏是必要的。
