Chapter 072. Malnutrition and Nutritional Assessment (Part 6)

AnthropometricsAnthropometric measurements provide information on body muscle mass and fat reserves. The most practical and commonly used measurements are body weight, height, triceps skinfold (TSF), and mid-arm muscle circumference (MAMC). Body weight is one of the most useful nutritional parameters to follow in patients who are acutely or chronically ill. Unintentional weight loss during illness often reflects loss of lean body mass (muscle and organ tissue), especially if it is rapid and not caused by diuresis. This can be an ominous sign since it indicates use of vital body protein stores as a metabolic fuel. ...
Nội dung trích xuất từ tài liệu:
Chapter 072. Malnutrition and Nutritional Assessment (Part 6) Chapter 072. Malnutrition and Nutritional Assessment (Part 6) Anthropometrics Anthropometric measurements provide information on body muscle massand fat reserves. The most practical and commonly used measurements are bodyweight, height, triceps skinfold (TSF), and mid-arm muscle circumference(MAMC). Body weight is one of the most useful nutritional parameters to followin patients who are acutely or chronically ill. Unintentional weight loss duringillness often reflects loss of lean body mass (muscle and organ tissue), especially ifit is rapid and not caused by diuresis. This can be an ominous sign since itindicates use of vital body protein stores as a metabolic fuel. The referencestandard for normal body weight, body mass index (BMI, or weight in kilogramsdivided by height, in meters, squared), is discussed in Chap 75. BMIs considered underweight, 18.5–24.9 are normal, 25–29.9 are overweight, and ≥30are obese. Measurement of skinfold thickness is useful for estimating body fat stores,because about 50% of body fat is normally located in the subcutaneous region.Skinfold thicknesses can also permit discrimination of fat mass from muscle mass.The TSF is a convenient site that is generally representative of the bodys overallfat level. A thickness of outlined in Table 72-5. The table also provides tips to help avoid assigningnutritional significance to tests that may be abnormal for nonnutritional reasons. Table 72-5 Laboratory Tests for Nutritional Assessment Test Nutritional Causes of Other Causes(Normal Values) Use Normal Value of Abnormal Value Despite Malnutrition Serum 2.8–3.5: Dehydratio Lowalbumin(3.5–5.5 Compromised ng/dL) protein status balance intake Burns, trauma Congestive heart failure Fluid overload Severe liver disease Uncommon: Nephrotic syndrome Zinc deficiency Bacterial stasis/overgrowth of small intestine Serum 10–15 Chronic Similar toprealbumin, also mg/dL: Mild renal failure serum albumincalled transthyretin protein depletion(20–40 mg/dL;lower in 5–10 mg/dL:prepubertal Moderate proteinchildren) depletion Serum total Anticoagulant therapy (warfarin) Severe liver disease Serum 24-h Lowcreatinine 500– muscle wasting due1200 mg/d to prolonged energy collection(standardized for deficitheight and sex) Decreasing Incomplete serum creatinine urine collection Increasing serum creatinine Neuromuscular wasting 24-h urinary Determineurea nitrogen level of catabolism(UUN) 5–10 g/d =mild catabolism ornormal fed state 10–15 g/d =moderatecatabolism >15 g/d =severe catabolism Estimateprotein balance Proteinbalance = proteinintake – protein losswhere protein loss(protein catabolicrate) = [24-h UUN (g) + 4] x 6.25 Adjustments required in burn patients and others with large nonurinary nitrogen losses and in patients with ...