Enteral nutrition prevents remote organ injury and death after a gut ischemic insult

Objective To determine whether parenteral feeding (IV-TPN) influences the local and systemic response to an intestinal insult. Summary Background Data Parenteral feeding increases ICAM-1 expression and attracts neutrophils (PMNs) to the intestine compared with enterally fed animals. Because the gut is a priming bed for PMNs, the authors hypothesized that IV-TPN may affect organ injury after gut ischemia-reperfusion (I/R). Methods Mice were randomized to chow, IV-TPN, intragastric TPN, or complex enteral diet for 5 days' feeding. In experiment 1, 162 mice underwent 15 or 30 minutes of gut I/R, and death was recorded at 72 hours. In experiment 2, 43 mice underwent 15 minutes of gut ischemia and permeability was measured by (125)l-labeled albumin at 3 hours after reperfusion. Lung PMN accumulation was measured by myeloperoxidase assay. In experiment 3, albumin leak was tested in the complex enteral diet group (n = 5) and the intragastric TPN group (n = 5) after 30 minutes of gut ischemia and 1 hour of reperfusion. Results In experiment 1, enteral feeding significantly reduced the death rate compared with IV-TPN after 15 minutes of I/R. After 30 minutes of gut ischemia, the IV-TPN and intragastric TPN groups showed a higher death rate than the chow and enteral diet groups. In experiment 2, IV-TPN significantly increased pulmonary and hepatic (125)l albumin leak compared with enteral feeding without increasing pulmonary myeloperoxidase levels. In experiment 3, there were no differences in (125)l albumin leak between the complex enteral diet and intra gastric TPN groups. Conclusion Enteral feeding reduced the death rate and organ permeability after 15 minutes of ischemia. However, prolonged ischemia (30 minutes) eliminated any benefits of intragastric TPN on survival.