Ketamine anesthesia reduces intestinal ischemia/reperfusion injury in rats

Abstract

To investigate the effects of ketamine anesthesia on the motility alterations and tissue injury caused by ischemia/reperfusion in rats. Thirty male Wistar rats weighing 200-250 g were used. Ischemia was induced by obstructing blood flow in 25% of the total small intestinal length (ileum) with a vascular clamp for 45 min, after which either 60 min or 24 h of reperfusion was allowed. Rats were either anesthetized with pentobarbital sodium (50 mg/kg) or ketamine (100 mg/kg). Control groups received sham surgery. After 60 min of reperfusion, the intestine was examined for morphological alterations, and after 24 h intestinal basic electrical rhythm (BER) frequency was calculated, and intestinal transit determined in all groups. The intestinal mucosa in rats that were anesthetized with ketamine showed moderate alterations such as epithelial lifting, while ulceration and hemorrhage was observed in rats that received pentobarbital sodium after 60 min of reperfusion. Quantitative analysis of structural damage using the Chiu scale showed significantly less injury in rats that received ketamine than in rats that did not (2.35+/-1.14 vs 4.58+/-0.50, P<0.0001). The distance traveled by a marker, expressed as percentage of total intestinal length, in rats that received pentobarbital sodium was 20%+/-2% in comparison with 25.9%+/-1.64% in rats that received ketamine (P=0.017). BER was not statistically different between groups. Our results show that ketamine anesthesia is associated with diminished intestinal injury and abolishes the intestinal transit delay induced by ischemia/reperfusion.