Nutrition (also see Chapter 77 )

As alluded to earlier, nutritional support is essential for massively injured trauma patients. Fewer complications result from enteral as opposed to parenteral feeding, and this route should be used whenever possible.^[263] Because the gut is one of the first regions to vasoconstrict in response to hemorrhage and one of the last to be completely resuscitated, enteral nutrition should not be started until late resuscitation is complete (usually 24 to 48 hours after injury). Ileus is common after trauma but will tend to resolve once enteral feedings begin. Because many severely injured trauma patients remain at risk for aspiration as a result of TBI, analgesics, or facial trauma, enteral feeding is usually initiated through a feeding tube. Nasogastric feeding is appropriate in the early stages of recovery; for patients who will require long-term support, a percutaneous endoscopic gastrostomy or jejunostomy is established. Patients undergoing abdominal surgery should have a feeding tube placed at the time of closure, typically during the "second-look" operation after an initial damage control procedure. Postpyloric feeding can be continued even if the patient is returning to the operating room multiple times; the risk for aspiration is slight, especially in an intubated or tracheotomized patient. A lower incidence of infectious complications and more rapid hospital discharge are associated with the early use of enteral feeding.^[264]

Late advances have led to a better understanding of the role that nutrition plays in the complex immune system of a critically injured patient. In a review of the published evidence that immune-enhanced diets are beneficial to patients after traumatic injury, Jurkovich discusses five current studies involving a total of 242 patients.^[265] Although the data were not consistently uniform in favor of immune-enhanced diets over standard diets, the results are suggestive of improved clinical outcome, fever, and infection and shorter ICU length of stay. These findings led the American Society for Parenteral and Enteral Nutrition to recommend immune-enhanced diets for patients with blunt and penetrating torso trauma and an injury severity score higher than 18 or an abdominal trauma score higher than 20.

Total parenteral nutrition is an effective alternative to enteral nutrition, particularly in patients at risk for malnutrition who cannot tolerate enteral feeding.^[266] Parenteral nutrition can also be used to supplement enteral feeding in a metabolically hyperactive trauma patient. Reactive oxygen species have been implicated as a contributor to MOSF, and the use of antioxidant supplements has been proposed as a solution.^[267] One small trial performed in penetrating trauma patients who received N-acetylcysteine, selenium, and vitamins C and E for 7 days showed fewer infectious complications and a lower incidence of organ dysfunction with this therapy, although this finding has yet to be confirmed in a larger trial.^[268]