Cardiac resuscitation by retroaortic infusion of blood

Current methods of closed-chest cardiac resuscitation generate coronary perfusion pressures that rarely exceed one fourth of normal, and this decreases with prolongation of cardiac arrest. The resuscitation effort is therefore almost uniformly unsuccessful when precordial compression is initiated after 8 minutes of untreated cardiac arrest. This report introduces a new option for cardiac resuscitation by infusion of oxygenated blood into the ascending aorta such as to transiently increase the pressure gradient for coronary perfusion. Thirty-six anesthetized, mechanically ventilated normovolemic rats were investigated. Cardiac arrest was induced with an alternating current delivered through an electrode catheter advanced into the right ventricle. Ventricular fibrillation was untreated for 4, 6, or 8 minutes, after which resuscitation was attempted without blood infusion, with infusion of oxygenated blood, or with infusion of oxygenated blood containing 30 mg/kg epinephrine. The boluses of blood were delivered through a catheter advanced from the right carotid artery into the ascending aorta. Except for mechanical ventilation and direct current precordial countershock for electrical defibrillation, no other mechanical resuscitation intervention, and specifically no precordial compression, was administered. None of six control animals that received either no retroaortic infusion or right atrial infusion was resuscitated after 4 minutes of untreated ventricular fibrillation. Each of five animals was successfully resuscitated by retroaortic infusion after 4 minutes of untreated cardiac arrest; one was resuscitated after 6 minutes, and none was resuscitated after 8 minutes.(ABSTRACT TRUNCATED AT 250 WORDS)