Mild Hypothermia Protects Pigs’ Gastric Mucosa After Cardiopulmonary Resuscitation via Inhibiting Interleukin 6 (IL-6) Production

BACKGROUND: The purpose of this study was to determine the effect of mild hypothermia therapy on gastric mucosa after cardiopulmonary resuscitation (CPR) and the underlying mechanism. MATERIAL/METHODS: Ventricular fibrillation was induced in pigs. After CPR, the surviving pigs were divided into mild hypothermia-treated and control groups. The changes in vital signs and hemodynamic parameters were monitored before cardiac arrest and at intervals of 0.5, 1, 2, 4, 6, 12, and 24 h after restoration of spontaneous circulation. Serum IL-6 was determined at the same time, and gastroscopy was performed. The pathologic changes were noted, and the expression of IL-6 was determined by hematoxylin and eosin (HE) staining and immunohistochemistry under light. RESULTS: The heart rate, mean arterial blood pressure, and cardiac output in both groups did not differ significantly. The gastric mucosa ulcer index evaluated by gastroscopy 2 h and 24 h after restoration of spontaneous circulation (ROSC) in the mild hypothermic group was lower than that the control group (P<0.05). The inflammatory pathologic score of gastric mucosa in the mild hypothermic group 6–24 h after ROSC was lower than that in the control group (P<0.05). Serum and gastric mucosa IL-6 expression 0.5–4 h and 6, 12, and 24 h after ROSC was lower in the mild hypothermic group than in the control group (P<0.05). CONCLUSIONS: Mild hypothermia treatment protects gastric mucosa after ROSC via inhibiting IL-6 production and relieving the inflammatory reaction.