Chapter 2: Surgical Nutrition
A 67-year-old woman is admitted to a general surgical floor with the diagnosis of a small bowel obstruction. Which of the following is the best initial nutritional assessment?
(E) History and physical examination
(E) The nutritional assessment of the surgical patient consists of a subjective (clinical) assessment combined with objective (biochemical) measures. The history and physical examination are the primary nutritional assessment tools. A thorough history should include recent weight loss, dietary intake, gastrointestinal symptoms, functional capacity, and symptoms focused on nutritional deficiency. Physical examination may reveal edema, poor wound healing, bruising, pale conjunctivae, or glossitis, among other signs.
While many different objective measures of nutritional status have been shown to be accurate and reproducible in clinical studies, body mass index (BMI) and prealbumin concentration are the most commonly used. Their popularity lies in the fact that they are inexpensive, simple, and reasonably accurate.
BMI is defined as weight (kg) divided by the square of height (m2). It is considered a more accurate indicator than ideal body weight (IBW) because it is less dependent on comparison to control populations. A BMI of less than 18.5 kg/m2 is associated with increased morbidity in hospitalized patients.
The serum albumin concentration correlates with global protein synthesis, degradation, and exchange between fluid compartments. However, albumin does not reflect acute changes in nutritional status because of its long half-life (18–21 days) and as a negative acute phase reactant it is decreased in acute inflammatory states, compared with prealbumin, which has a half-life of 48 hours. A serum albumin level of less than 3.5 g/dL is associated with increased morbidity in hospitalized patients. A prealbumin of 5 to 10 mg/dL indicates moderate nutritional depletion.
Glutamine is an important nutrient for the maintenance of gut mucosa during stress; however, it has been proposed as an additive to feeding solutions, and not as a nutritional marker.
Carney DE, Meguid MM. Current concepts in nutritional assessment. Arch Surg 2002;137:42–45.
Martindale RG, Zhou M. Nutrition and metabolism. In: O’Leary JP, ed. The Physiologic Basis of Surgery. 4th ed. Baltimore, MD: Lippincott Williams & Wilkins; 2008:112–149.
A 34-year-old man is mechanically ventilated in the intensive care unit after a closed head injury. He is 5′11″ tall and weighs 176 lb. He has no burns, has not had surgery, and shows no signs of sepsis. Which of the following is his estimated caloric requirement per 24 h?