Abstract 161: 60 Minutes of Cardiac Rescue and Stabilization with a Small Intravenous Bolus of Adenocaine Following 8 Minutes of Asphyxial Hypoxia in the Rat in Vivo: Effect of Therapeutic Hypothermia
Sudden cardiac death claims more than 7,000,000 lives per year globally and a survival rate of 2 to 8% for out-of-hospital cardiac arrest (OHCA) victims has not improved in 30 years. Previously we reported that Adenocaine (adenosine and lidocaine) can arrest and reanimate the heart for use in cardiac surgery/transplantation, and that 7.5% NaCl/Adenocaine/Mg2+ can resuscitate the rat following severe hemorrhagic shock. Our aim was to examine Adenocaine's ability to rescue and stabilize the heart following 8 min of asphyxial hypoxia in the rat model of cardiac arrest at warm (37°C) and cold (rectal 32-33°C) temperatures.
Methods: Male fed Sprague-Dawley rats (300-380g, n=24) were anesthetized and assigned to one of four groups: 1) Saline control (warm), 2) Saline control (cold), 3) Adenocaine (warm), 4) Adenocaine (cold). After obtaining baseline data, cardiac arrest (MAP < 10 mmHg) was induced by turning off the ventilator for 8 min. A 0.5 ml bolus was injected IV followed by 30 sec chest compressions (300/min), which were repeated every 5 min for 60 min. During compression and hands-off periods, systolic arterial pressure (SAP), diastolic arterial pressure (DAP), HR and ventricular tachycardia (VT) and fibrillation (VF) were measured. Return of Spontaneous Circulation (ROSC) was defined as a SAP > 20 mmHg.
Results: After 5 min resuscitation, no warm controls and 67% of cold controls achieved ROSC. ROSC was achieved during each of the 5 min hands-off periods in cold controls until 20 min (33%). 17% of Adenocaine warm rats and 100% of Adenocaine cold rats achieved ROSC after 5 min. After 20 min, 67% of Adenocaine cold rats achieved ROSC, 50% after 30 min and 33% of rats after 40 min (doubling the ROSC window). During chest compressions, MAP, SAP and DAP were significantly higher in Adenocaine cold rats than all groups from 30 to 60 min. At 60 min, the MAP, SAP and DAP for Adenocaine cold rats were 19 ± 3, 21 ± 3 and 17 ± 3 mmHg. Saline controls (warm and cold) experienced a large number of VT and VF whereas both Adenocaine groups had no VF over 60 min.
Conclusion: A single IV Adenocaine bolus significantly extended ROSC, cardiac rescue and stabilization with no VF during hypothermia over 60 min. Adenocaine with therapeutic hypothermia may offer a new strategy for OHCA and combat casualties.
- © 2011 by American Heart Association, Inc.