GRAINS OR VEINS - IS ENTERAL NUTRITION REALLY BETTER THAN PARENTERAL-NUTRITION - A LOOK AT THE EVIDENCE

Background: Enteral nutrition is said to be better than parenteral nut rition for providing nutrition support to humans. Purpose: To assess t he literature documenting the assertions that enteral nutrition is sup erior to parenteral nutrition with respect to cost, safety, physiology , intestinal structure and function, bacterial translocation, and outc ome. Data identification: Sources included MEDLINE search, personal fi les, and references horn human comparative studies of enteral vs paren teral nutrition. Study selection: The goal was to include all human st udies directly addressing questions of comparative efficacy of enteral and parenteral nutrition. Emphasis was given to prospective randomize d controlled studies where available. Retrospective comparisons were n ot included. Data extraction: An attempt was made to briefly summarize methodology and findings of relevant studies. No general attempt was made to assess quality of individual studies. Results of data synthesi s: Enteral nutrition appears to be less expensive than parenteral nutr ition, but new economic analyses are needed given the newer aggressive ac cess techniques for enteral nutrition. Enteral nutrition is associ ated with meaningful morbidity and mortality. The little comparative d ata existent suggest no differences in safety. Comparative studies of physiology and metabolism as well as comparative and noncomparative st udies of intestinal function and structure do not support putative adv antages of enteral nutrition. There is no evidence that enteral nutrit ion prevents bacterial translocation in humans. Enteral nutrition prob ably reduces septic morbidity compared with parenteral nutrition in ab dominal trauma. Otherwise, there is no evidence that enteral nutrition consistently improves patient outcome compared with parenteral nutrit ion. Conclusions: With the exception of decreased cost and probable re duced septic morbidity in acute abdominal trauma, the available litera ture does not support the thesis that enteral nutrition is better than parenteral nutrition in humans.