Sudden death in severe gut ischemia: a possible role for the autonomic nervous system

Abstract

Occlusion of blood vessels in the gut is a life‐threatening event. For example, splanchnic arterial occlusion (SAO) followed by reperfusion is an established model for physiologic shock. In addition SAO is highly lethal on its own, either associated with gradual drops in mean arterial blood pressure (MABP) over <1 to 3 hours or with a severe rapid drop in MABP (often > 80 mmHg) over 1 to 6 minutes, leading to left ventricular arrest. The rapid drop occurs after ~ 75‐150 min of ischemia. We observed that high levels of glucose in the lumen of the small intestine decrease the ischemic duration before which a rapid drop may be observed (as early as 30 min) and increase its rate of occurrence (from 29% to 63%). As afferent neurons in the gut are capable of sensing ischemia and/or hyperglycemia, our objective was to determine whether a total subdiaphragmatic vagatomy (TSV), which prevents parasympathetic sensing in the gut, could prevent the rapid drop in MABP. We found that survival time was increased by TSV (P<0.05). While not preventing the gradual drops in MABP, TSV significantly reduced the instances of rapid drops in MABP (P<0.008). These results suggest that meals high in glucose and parasympathetic sensing in the gut may greatly affect the amount of time available to treat gut ischemia before catastrophic cardiovascular failure. Supported in part by HL 67825, 76180 and an unrestricted educational gift from Leading Ventures.