Nutrition support in the critically ill patient.

Despite an absence of well-controlled studies demonstrating a clear mortality benefit, providing nutrition support in the critically ill patient has become routine in most ICU settings. Unless clearly contraindicated, patients should be fed enterally, using conventional isotonic feedings employing gastric or postpyloric access. When to begin nutrition support varies, depending on baseline nutritional status, anticipated time until oral feedings are resumed, and the degree of stress. Energy and protein requirements should be assessed routinely with minimum goals of avoiding overfeeding and minimizing any net negative nitrogen balance. All patients receiving feedings require close surveillance to identify predictable complications and to tailor therapy to achieve nutritional goals. Adjunctive therapies should be employed as needed to help achieve nutritional goals, eg, insulin infusions to control serum glucose and prokinetic agents to improve gastric emptying. When feasible and safe, parenterally fed patients should be transitioned to enteral or oral feedings when appropriate.