Establishment of enteral nutrition: prokinetic agents and small bowel feeding tubes

Nutritional support is vital to improving the clinical outcomes in patients in the intensive care unit. Enteral nutrition should be administered early and aggressively, thereby reducing the need for parenteral nutrition. Because nasogastric feeding is often associated with gastrointestinal intolerance, recent research has focused on the use of prokinetic agents or small bowel feeding tubes to enhance the successful establishment and maintenance of enteral nutrition.

Prokinetic agents (such as metoclopramide and erythromycin) improve markers of gastric emptying and appear to improve tolerance of enteral nutrition, although their effects on clinical outcomes are not as well established. In comparison with nasogastric feeding, small bowel feeding allows the dysfunctional stomach of the critically ill to be bypassed, thereby reducing the rate of gastrointestinal complications and probably the risk of pneumonia. Small bowel tubes are more difficult to place than nasogastric tubes, although the new Tiger tube appears very promising.

Nasogastric feeding is preferred for almost all patients in the intensive care unit. Metoclopramide is the preferred prokinetic agent, although whether it or erythromycin should be administered to all patients in the intensive care unit or only those with gastrointestinal intolerance remains unknown. Small bowel feeding is not currently recommended for all patients in the intensive care unit because the benefits do not appear to outweigh the logistic and cost considerations. Nevertheless, when gastrointestinal intolerance develops in a nasogastrically fed patient, a small bowel feeding tube should be inserted at the earliest opportunity.