TARGETED TEMPERATURE MANAGEMENT AT 36°C IMPROVES SURVIVAL AND PROTECTS TISSUES BY MITIGATING THE DELETERIOUS INFLAMMATORY RESPONSE FOLLOWING HEMORRHAGIC SHOCK.

Abstract: Hemorrhagic shock (HS) is a life-threatening condition with high mortality rates despite current treatments. This study investigated whether targeted temperature management (TTM) could improve outcomes by modulating inflammation and protecting organs following HS. Using a rat model of HS, TTM was applied at 33°C and 36°C after fluid resuscitation. Surprisingly, TTM at 33°C increased mortality, while TTM at 36°C significantly improved survival rates. It also reduced histological damage in lung and kidney tissues, lowered serum lactate levels, and protected against apoptosis and excessive reactive oxygen species production. TTM at 36°C inhibited the release of high mobility group box 1 protein (HMGB1), a key mediator of inflammation, and decreased proinflammatory cytokine levels in the kidneys and lungs. Moreover, it influenced macrophage behavior, suppressing the harmful M1 phenotype while promoting the beneficial M2 polarization. Cytokine array analysis confirmed reduced levels of proinflammatory cytokines with TTM at 36°C. These results collectively highlight the potential of TTM at 36°C as a therapeutic approach to improve outcomes in HS. By addressing multiple aspects of injury and inflammation, including modulation of macrophage responses and cytokine profiles, TTM at 36°C offers promising implications for critical care management after HS, potentially reducing mortality and improving patient recovery.