Abstract 148: Differential Neuroprotective Effects of Targeted Temperature Management in Adult and Aged Rats Post-Cardiac Arrest

Abstract

Background: Targeted temperature management (TTM) has been recognized as a crucial brain protective method post-cardiac arrest (CA). However, its efficacy has recently been questioned due to several clinical trials. Hypothesis: TTM may not offer significant neuroprotective benefits in older individuals post-CA. Aims: This study aims to evaluate the therapeutic efficacy of TTM on neurological dysfunction in aged rats post-CA. Methods: Fifty-six male Sprague-Dawley (SD) rats were divided into two age groups: adult group (3-4 months, n=28) and aged group (19-22 months, n=28). Each group was then randomized into four subgroups: 1) sham, 2) sham + TTM, 3) control, 4) control + TTM. Control and control + TTM groups underwent 6 minutes of asphyxiation followed by cardiopulmonary resuscitation. TTM was applied at 32-34°C for 2 hour post-return of spontaneous circulation (ROSC). Neurological outcomes were assessed five days post-CA using the Y-maze and the Open field test. Serum IL-17 and IL-6 levels were measured four hours post-CA. Results: TTM significantly enhanced the spontaneous alternation in the Y-maze (p <0.05), increased moter active in Open field test (p<0.05), and reduced serum IL-17 and IL-6 levels in the adult group (p <0.05). Conversely, in the aged group, TTM did not exhibit any significant benefits in Y maze performance, Open field test, IL-17 or IL-6 serum levels reduction (p >0.05). Conclusion(s): TTM demonstrated improvement in post-CA neurological deficits in adult rats, yet it failed to deliver similar benefits in aged rats. IL-6 and IL-17 might play a role in the differential neuroprotective effects of TTM.