Abstract 11376: Combination of Pharmacologically and Surface Cooling Induced Hypothermia in a Porcine Model of CPR
Background: Mild hypothermia improves the outcomes of CPR. However, currently available techniques for inducing hypothermia are either difficult to achieve target cooling temperature or cumbersome for early application. In this study, we investigated the efficacy of a combination of pharmacological and physical cooling in a porcine model of CPR. Hypothesis: We hypothesized that when the surface cooling combined with a cannabinoid receptor agonist, WIN 55, 212-2, the target cooling temperature could be established in a significantly shorter duration when compared with either surface cooling or pharmacologically induced hypothermia.
Methods: Ventricular fibrillation was electrically induced and untreated for 7 mins in 28 male swine weighing 35±2kg. Defibrillation was attempted after 5 mins of CPR. The resuscitated animals were randomized in to 4 groups 1) Normothermic, 2) WIN55, 212-2, 3) Surface cooling, 4) WIN55, 212-2 + surface cooling (Combination). The animals were either intravenous infused of WIN 55, 212-2 (1.0mg/kg/h) or the same amount of saline vehicle at 5 mins post-resuscitation. The cooling blanket was utilized for surface cooling.
Results: The blood temperature was significantly decreased in all hypothermic animals. It was reduced to 34°C ± 0.6 at 90 mins and to 32°C ± 0.7 at 135 mins in animals treated with combination cooling. This was contrasted with WIN55, 212-2 or surface cooling alone groups in which the blood temperature was 36°C ± 0.6 and 35°C ± 1 at 90 and 35.5°C ± 0.8 and 34°C ± 1.3 at 135 mins, respectively (p<0.01). None of the animals with a single cooling method reached 32°C. The heart rate and arterial pressure were significantly lower in both of WIN55, 212-2 and combination groups compared with normothermic and surface cooling group.
Conclusions: Combination of pharmacological and physical cooling rapidly achieved the target cooling temperature when compared with surface cooling or pharmacologically induced hypothermia alone.
- © 2012 by American Heart Association, Inc.