Nutrition and severe brain injury

Patients with severe brain injuries have increased energy expenditures and urinary nitrogen excretion. Hypozincemia, hypoferremia, increased levels of acute phase proteins, depressed levels of negative acute phase proteins, and weight loss are common in these patients. The specific mediators of these responses are not known. Nutritional support may beneficially affect outcome in these patients, but enteral feedings are often not tolerated in the acute phase of injury. Animal investigations suggest that total parenteral nutrition and hyperglycemia may increase neuronal injury and worsen outcome. We review the current literature on nutritional support of brain-injured patients and examine the premises on which nutrition supplementation are based. More work is needed to define the metabolic responses and nutritional requirements of patients who sustain central nervous system injury.