Abstract 13814: Lack of a Beneficial Effect on Neurologic Outcome When Mild Therapeutic Hypothermia is Augmented with the Noble Gas Argon after Cardiac Arrest
Introduction: Experimentally, combining xenon and mild therapeutic hypothermia (MTH) after cardiac arrest (CA) confers a degree of protection that is greater than either of the two interventions alone. However, xenon is very costly which might preclude a widespread use. We investigated if the more available argon would also further enhance hypothermia induced neurologic recovery. Material and
Methods: Following 9 mins of CA and 3 mins of cardiopulmonary resuscitation (CPR) 28 male Sprague-Dawley rats were randomized to receive MTH (33°C for 6 hrs), MTH plus argon (70% for 1h), argon alone or no treatment. A condition score, assessing behaviour, motor activity and overall condition, was calculated on the first day post-arrest as well as the number of rats having seizures during the seven days following the experiment. Post experimental core temperature was measured by an implantable thermocouple probe and recorded for 16 hrs.
Results: All animals survived. MTH treated animals showed best overall neurologic function. Strikingly, this effect was abolished in the argon-augmented MTH group, where animals showed worse neurologic outcome being significant in the first day condition score (Fig.1) and in the number of animals having seizures during the seven post-arrest days in comparison to MTH treated rats (Fig.2). This was paralleled by a significant temperature drop early in the first post arrest night in the MTH plus argon group in comparison to the control group.
Conclusions: Our study demonstrates that argon augmented MTH does not additionally improve functional outcome after CA in rats, but may even worsen neurologic function.
- © 2012 by American Heart Association, Inc.