Abstract 162: Short-Term Combined Mild Hypothermia Improves Neurological Outcome in Porcine Model of Prolonged Ventricular Fibrillation
Introduction: Mild therapeutic hypothermia (MTH) of 32 to 34 °C maintaining for 12 to 24 hours is recommended for patients returned spontaneous circulation (ROSC) from cardiac arrest with benefit of neurological preservation. In present study, we investigated whether a short-term combined mild hypothermia could improve resuscitation outcome in porcine model of prolonged ventricular fibrillation.
Hypothesis: Maintaining two hours of MTH after ROSC can alleviated neurological deflect and neuron apoptosis in a porcine model.
Method: Fourteen domestic pigs weighted 35 to 37 kg were anesthetized and core temperature was obtained via a thermo-sensor in the right atrial. Ventricular fibrillation was induced electrically and maintained untreated for 11 mins. Two investigators delivered CPR with 30:2 compression-to-ventilation ratio for 6 mins. A 150-J electric shock was attempted and animals ROSC were then randomized into combined mild hypothermia (CMH) or normothermia groups (NT). In CMH, ice-cold saline (30ml/kg) was infused via right atrial to induce MTH together with surface cooling. Cooling rate was 2.5°C/hour in a two-hour inducing duration. Target temperature was maintained for 120 mins before another two-hour active rewarming phrase. Cerebral performance category (CPC) and neurological deflect score (NDS) were evaluated every 24 hours. An immunohistochemical method (TUNEL) was used to evaluate neurons apoptosis in hippocampus CA1 at the 96 hour.
Result: There were no differences of hemodynamic, compression depth, shocks and epinephrine use in both groups. All animals were successfully resuscitated. The NDS and CPC in CMH were better than that in NT (Table 1). For TUNEL, number of apoptosis neurons in NT was significantly more than that in CMH.
Conclusion: Even maintaining only two hours of MTH after ROSC can improve neurological outcome and reducing neuron apoptosis in porcine model of prolonged ventricular fibrillation.
Author Disclosures: H. Li: None. Z. Yang: None. Z. Huang: None. Y. Li: None. T. Yu: None.
- © 2014 by American Heart Association, Inc.