Challenges in determining calorie and protein dosing in critically ill patients with obesity

PURPOSE: To describe challenges in and provide current practical guidance for devising calorie and protein regimens for critically ill patients with obesity with a focus on clinicians who do not specialize in nutrition support. SUMMARY: It has been over a decade since the American Society for Parenteral and Enteral Nutrition published a clinical practice guideline focusing on nutrition support in adult hospitalized patients with obesity. A literature review of recent studies and guidelines revealed no substantial evidence that predictive equations for estimating energy expenditure are more valid or reliable than weight-based dosing regimens of kcal/kg/day using some form of adjusted body weight for patients with obesity. Similarly, weight-based dosing regimens of g/kg/day of protein using some form of adjusted body weight for patients with obesity are a practical initial approach for many patients. During the early acute phase, lower initial calorie and protein delivery may be appropriate for many critically ill patients with obesity; however, this approach should not be applied uniformly to profoundly hypermetabolic or highly catabolic populations. Nutrition should be initiated without unnecessary delay when clinically appropriate and progressively advanced toward individualized goals as the patient stabilizes and enters recovery. CONCLUSION: Weight-based calorie and protein dosing provides a practical starting method for many critically ill patients with obesity when indirect calorimetry is unavailable or not technically valid. Initial prescriptions should be individualized according to nutrition status, metabolic phenotype, severity and type of illness, and phase of recovery. Hypermetabolic populations may require a different approach and the early involvement of nutrition support specialists.