Feeding the gut: how, when and with what -- the metabolic issue.

PURPOSE OF REVIEW: To review the literature on feeding critically ill patients with special emphasis on the intestine.

RECENT FINDINGS: Many dogmas have been questioned in the past few years. In particular, the absence of evidence for impact on outcomes in critically ill patients has been highlighted. So 'early enteral feeding', the trophic effect on intestinal mucosa in humans, 'pharmaco-nutrition', postpyloric feeding and prokinetic drugs have all been found to lack proper evidence to affect outcomes.

SUMMARY: The use of gastric feeding in critical illness is recommended. Successful gastric feeding is indicative of a functional gastrointestinal tract. Pharmacological effects of nutrients are questionable, but supplementation of deficits (glutamine, selenium, etc.) may be in the patient's best interest. A more individualized prescription of nutrition in the critically ill is advocated.