[Experimental study on gut tolerance to early enteral nutrition following intestinal ischemia/reperfusion]

To investigate the effects of early enteral nutrition (EEN) on intestinal function and gut tolerance after intestinal ischemia/reperfusion (I/R) injury.

Twenty-four male dogs were randomly divided into three groups: EEN only, I/R only and I/R+EEN. The superior mesenteric artery (SMA) was blocked for 1 hour followed by restoration of blood flow. EEN was given 4 hours after reperfusion by continuous infusion of Fresubin nutrition fluid (4 ml.kg(-1).h(-1), Fresenius Kabi Co, Germany) into gut via a tonometric catheter for 3 hours till intolerance symptoms, which including vomiting and diarrhea which indicated gut intolerance. CO(2) partial pressure of intestinal mucosa (PiCO(2)), D-xylose absorption and intestinal luminal pressure were measured to reflect intestinal function and perfusion.

Incidence and severity of diarrhea and vomiting were significantly higher in I/R+EEN group (with 87.5% intolerance) than those in I/R only group (12.5%) and EEN only group (0). After EEN, PiCO(2) and intestinal cavity pressure were significantly higher, and the D-xylose absorption much lower, in the I/R+EEN group compared with the I/R group and EEN group (all P<0.01).

Intestinal I/R may result in decreased tolerance to EEN. Too early enteral nutrition (less than 12 hours after gut hypoperfusion) may enhance intestinal ischemia injury and further inhibit its function of propulsion and absorption.