Nutritional support of the critically ill patient.

Protein-calorie malnutrition is prominent among patients undergoing gastrointestinal tract operations who are admitted as an emergency measure to the intensive care unit. Immediate feedings postoperatively with an elemental diet through a jejunostomy catheter can provide an alternative method of nutritional support in these critically ill patients. In patients with extremely high metabolic demands, it may be necessary to combine enteral feeding with parenteral support to achieve positive nitrogen balance.