Critically ill patients often require nutrition support, but accurately determining energy needs in these patients is difficult. Energy expenditure is affected by patient characteristics such as weight, height, age, and sex but is also influenced by factors such as body temperature, nutrition support, sepsis, sedation, and therapies. Using predictive equations to estimate energy needs is known to be inaccurate. Therefore, indirect calorimetry measurement is considered the gold standard to evaluate energy needs in clinical practice. This review defines the indications, limitations, and pitfalls of this technique and gives practice suggestions in various clinical situations.
Keywords: calories; energy expenditure; energy intake; energy metabolism; indirect calorimetry.
© 2015 American Society for Parenteral and Enteral Nutrition.