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

Objective To determine whether parenteral feeding (IV-TPN) influences the l ocal 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 an imals. 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 measure d by (125)l-labeled albumin at 3 hours after reperfusion. Lung PMN accumula tion was measured by myeloperoxidase assay. In experiment 3, albumin leak w as tested in the complex enteral diet group (n = 5) and the intragastric TP N group (n = 5) after 30 minutes of gut ischemia and 1 hour of reperfusion. Results In experiment 1, enteral feeding significantly reduced the death ra te compared with IV-TPN after 15 minutes of I/R. After 30 minutes of gut is chemia, the IV-TPN and intragastric TPN groups showed a higher death rate t han 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 ent eral diet and intra gastric TPN groups. Conclusion Enteral feeding reduced the death rate and organ permeability af ter 15 minutes of ischemia. However, prolonged ischemia (30 minutes) elimin ated any benefits of intragastric TPN on survival.