No single biochemical test or clinical technique is sufficiently accurate to serve as a reliable test for malnutrition. Techniques of nutritional assessment utilize a combination of methods, including evaluation of dietary intake, anthropometric measurements, clinical examination, and laboratory tests.
Patients undergoing a history and physical examination should be asked questions to help identify those high-risk patients who require further evaluation for malnutrition. Of particular importance are the regularity and availability of meals; who does the shopping and food preparation; recent changes in appetite, intake, or body weight; use of special diets or dietary supplements; use of alcohol, drugs, or medications; food preferences and food allergies; and the presence of illnesses affecting nutritional intakes, losses, or requirements. Elderly and adolescent patients, pregnant or lactating women, patients of lower socioeconomic status, and patients who are socially isolated are at particular risk for nutritional deficiencies.
Further quantification of dietary intake can be performed using a variety of techniques. Twenty-four-hour diet recalls provide rough estimates of nutrient intake. Patients are asked to describe their dietary intake over the preceding day, including snacks, beverages, and alcohol. Problems with this technique include poor patient recall, difficulties in estimating serving sizes, and the inaccuracy associated with generalizing from a single day's intake. More accurate information can be obtained by asking patients to complete a 3- to 5-day diet record. Nutrient composition can then be analyzed with the aid of standard handbooks or computer software. Although prospective and less likely to be invalidated by memory lapses, omissions are still common, and the usual difficulties in estimating serving size persist.
A nutritionally focused physical examination should be performed on each patient at risk for nutritional problems. The examination targets body weight, muscle wasting, fat stores, volume status, and signs of micronutrient deficiencies (eTable 29–7).
eTable 29–7.Clinical signs that may be due to nutrient deficiency. ||Download (.pdf) eTable 29–7. Clinical signs that may be due to nutrient deficiency.
|Clinical Sign ||Nutrient Deficiency ||Clinical Sign ||Nutrient Deficiency |
|Hair || ||Neck || |
| Transverse depigmentation ||Protein, copper || Goiter ||Iodine |
| Easily pluckable ||Protein ||Chest || |
| Sparse and thin ||Protein, zinc, biotin ||Thoracic rosary ||Vitamin D |
|Skin || ||Heart || |
| Dry, scaling ||Zinc, vitamin A, essential fatty acids || |
| Flaky paint dermatitis ||Protein, niacin, riboflavin ||Abdomen || |
| Follicular hyperkeratosis ||Vitamins A and C || Hepatosplenomegaly ||Protein–calorie |
| Perifollicular petechiae ||Vitamin C || Distention ||Protein–calorie |
| Petechiae, purpura ||Vitamins C and K ||Diarrhea ||Niacin, folate, vitamin B12 |
| Pigmentation, desquamation ||Niacin || Extremities || |
| || || Muscle tenderness, pain ||Thiamine, vitamin C |
| Nasolabial seborrhea ||Niacin, riboflavin, pyridoxine || Muscle wasting ||Protein–calorie |
| Pallor ||Iron, folate, vitamin B12, copper || Edema ||Protein, thiamine |
| Scrotal/vulvar dermatoses ||Riboflavin || Bone tenderness ||Vitamin C, vitamin D, calcium, phosphorus |
| Subcutaneous fat loss ||Calories || || |
|Nails || ||Neurologic || |
| Spooning ||Iron || Hyporeflexia ||Thiamine |
| Transverse lines, ridging...|