Nutrition and the use of metabolic assessment in the ventilator-dependent patient.

Nutritional support is an important aspect of care in hospitalized patients, especially those receiving mechanical ventilation. While nutritional assessments can help guide the clinician in determining appropriate caloric intake requirements and refeeding schedules, few tools exist to evaluate the consequences of over- or underfeeding. Metabolic assessment using indirect calorimetry is a new method of nutritional assessment for use at the bedside of the weaning patient. The data obtained from a metabolic assessment can be used to adjust formulas and total caloric intake as well as differentiate between dead space and elevated carbon dioxide production as reasons for persistent hypercarbia.