Abstract 250: Effects of Mild Hypothermia on Cerebral Lactate Metabolism in a Rat Model of Cardiac Arrest
Introduction: A strong relationship between lactate clearance rate and better outcomes in patients of cardiac arrest (CA) has been demonstrated. Mild hypothermia improves neurological outcomes and survival after CA. In the present study, we investigated the effect of mild hypothermia on cerebral lactate metabolism in a rat model of CA.
Hypothesis: Mild hypothermia accelerates cerebral lactate clearance rate in a rat model of CA.
Methods: Ten male Sprague-Dawley rats were randomized into two groups: hypothermic (HT, n=5) and normothermic (NT, n=5) groups. After 8 mins of untreated ventricular fibrillation, precordial compression and mechanical ventilations were initiated for 8 mins. The core temperature was decreased to 33±0.5°C after 14 mins of resuscitation with a combination of ice packs, an electrical fan and a cooling blanket. The temperature was maintained at 33°C for 8 hrs. The jugular vein lactate concentration was measured at baseline (BL), 2, 4 and 8 hrs after resuscitation (PR 2, 4 and 8 hrs).
Results: No significant difference in lactate concentrations was observed between the HT and NT group at BL and PR 2 hrs (BL: 0.9±0.12 vs 0.92±0.16 mmol/L, p=0.83; PR 2 hrs: 2.9±0.16 vs2.94±0.26 mmol/L, p=0.78). Cerebral lactate clearance rate was significantly increased in the HT group when compared to that in the NT group (68.2±3.33% vs. 55.3±3.03%, p<0.01) at PR 4 hrs. There was no significant difference in the cerebral lactate clearance rate between the HT group and NT groups at PR 8 hrs (70.9±3.37% vs 71.5±1.37%, p=0.76) (Figure).
Conclusion: Mild hypothermia accelerates the cerebral lactate clearance rate following resuscitation which may provide an additional underlying mechanism of cerebral protection.
Author Disclosures: J. Wang: None. P. Gong: None. S. Zhao: None. J. Qian: None. Z. Yang: None. X. Wu: None. J. Cahoon: None. N. Duggal: None. W. Tang: None.
- © 2014 by American Heart Association, Inc.