Nutrition considerations in the management of ventilator-dependent patients.

Nutrition support of the patient with ventilatory failure is an important adjunct to recovery. Malnutrition and respiratory failure are frequently interrelated. Ventilator dependence occurs when the patient cannot independently sustain oxygenation, carbon dioxide removal, or acid-base balance. Nutrition assessment, determination of energy requirements, and provision of nutrient solutions utilizing the most appropriate route of administration should be initiated early in the ventilator-dependent patient's hospital course. Careful assessment will identify patients needing repletion along with maintenance calories, as well as special macronutrient and micronutrient needs. The nutrient prescription is designed to provide carbohydrate, protein, and fat in amounts for optimal substrate utilization. Body fluid balance, micronutrient needs, electrolyte homeostasis, and acid-base balance affect respiratory muscle function and must also be considered in developing the nutrition regimen. Properly constructed enteral or parenteral nutrition plans begun early offer the best support for ventilator-dependent patients.