Topical Neck Cooling Attenuates Inflammatory Responses and Sepsis Progression in Intra-abdominal Sepsis

Abstract

INTRODUCTION: Advances in therapies to treat sepsis beyond source control, antibiotics, and supportive care are lacking. Systemic hypothermia has been suggested but remains difficult to implement. Using a swine model of intra-abdominal sepsis, we hypothesize that topical neck cooling (TNC) can inhibit inflammation to preserve organ function and prolong the therapeutic window for intervention via a vagus nerve–mediated pathway. METHODS: Domestic pigs underwent laparotomy and induction of severe feculent peritonitis (FP) by extraction of autologous stool (2 g/kg swine weight) via colotomy, dilution in saline, and subsequent injection into the peritoneal cavity. Pigs were randomized to control and TNC groups, with TNC applied to the ventral neck for a 2-hour period 30 minutes after FP. Hemodynamic monitoring and serial bloodwork was performed for 6 hours. Organs were then harvested. RESULTS: TNC significantly attenuated FP-induced tachycardia by 127% (54% ± 8% increase from TNC baseline vs 181% ± 44% increase from control baseline, p < 0.05). Metabolic acidosis and lactic acidemia at 6 hours were significantly increased from pre-septic baseline in control pigs (pH 7.29 ± 0.03 vs pH 7.41 ± 0.03 and 2.42 ± 0.40 mmol/L vs 0.61 ± 0.22 mmol/L, respectively, p < 0.05), but not in TNC-treated pigs. Proinflammatory cytokines IL-1β and IL-6 were significantly reduced by TNC treatment (p < 0.05; Figure).Figure.: FP, feculent peritonitis; TNC, topical neck cooling.CONCLUSION: In a swine model of severe FP, TNC significantly inhibited FP-induced severe tachycardia, potentially via vagal activation. TNC also improved tissue perfusion and metabolic acidosis and inhibited proinflammatory responses. TNC is an easily implemented novel therapy that can potentially delay sepsis progression and extend the therapeutic window for surgical source control.