Question

write a essay on; Nutrition assessment: anthropometrics, biochemical measurements and physical assessment. why aren't albumin and prealbumin labs not reliable indicators of nutrition status.

Answer 1

Nutritional assessment is the interpretation of anthropometric, biochemical (laboratory), clinical and dietary data to determine whether a person or groups of people are well nourished or malnourished (over-nourished or under-nourished).

Nutritional assessment can be done using the ABCD methods. These refer to the following:

• A.Anthropometry
• B.Biochemical/biophysical methods
• C.Clinical methods
• D.Dietary methods.

The word anthropometrycomes from two words: Anthropo means ‘human’ and metry means ‘measurement’. In your community you will be able to use anthropometric measurements to assess either growth or change in the body composition of the people you are responsible for. The different measurements taken to assess growth and body composition are presented below.

5.2  Anthropometric measurements used to assess growth

To assess growth in children you can use several different measurements including length, height, weight and head circumference.

5.2.1  Length

A wooden measuring board (also called sliding board) is used for measuring the length of children under two years old to the nearest millimetre (as shown in Figure 5.1). Measuring the child lying down always gives readings greater than the child’s actual height by 1-2 cm.

Weight

A weighing sling (spring balance), also called the ‘Salter Scale’ is used for measuring the weight of children under two years old, to the nearest 0.1 kg. In adults and children over two years a beam balance is used and the measurement is also to the nearest 0.1 kg. In both cases a digital electronic scale can be used if you have one available. Do not forget to re-adjust the scale to zero before each weighing. You also need to check whether your scale is measuring correctly by weighing an object of known weight.

Biochemical assessment uses laboratory measurements of serum protein, serum micronutrient levels, serum lipids, and immunological parameters to assess general nutritional status and to identify specific nutritional deficiencies. Specific laboratory tests most frequently used include measurements of albumin, prealbumin, hemoglobin, serum iron, total iron-binding capacity, magnesium, vitamin levels, trace elements, cholesterol, triglycerides, fasting glucose, CD4, CD8, virus load of HIV, renal function, and liver enzyme levels [22].

Clinical assessment includes a medical history and a physical examination to identify signs of or contributors to malnutrition. Key areas in the clinical assessment include physical appearance, evaluation of opportunistic infections and comorbid conditions, occurrence of diarrhea, symptoms of gastrointestinal distress or malabsorption, medications, use of nutritional or herbal supplements, and functional status. Assessment of social, psychological, and financial resources that may affect an individual's ability to obtain, prepare, and eat food are as important as the medical assessment in evaluating nutritional risk factors.

When malnutrition is suspected, lab tests often are ordered. Historically, serum proteins — albumin, prealbumin (PAB), transferrin, and retinol-binding protein (RBP) — were used to measure malnutrition. C-reactive protein (CRP), total lymphocyte count (TLC), and serum total cholesterol are not serum proteins but sometimes are used as indicators of malnutrition. Normal ranges for these lab tests are listed in Table 2. Despite the standard use of lab tests to help diagnose malnutrition, experts have no consensus about which, if any, biochemical markers identify malnutrition, especially in the frail, elderly population.

Albumin frequently is ordered to assess protein stores and test results are found in virtually every patient’s medical record. Some medical professionals believe a low serum albumin level indicates a need for protein repletion. However, serum albumin (as well as other serum proteins) is a negative acute-phase reactant — ie, it decreases in the presence of inflammation, which occurs in situations that cause physical stress to the body, such as trauma, surgery, burns, or a chronic illness such as cancer, heart disease, or hepatic failure. This complicates the usefulness of serum proteins as indicators of malnutrition or protein status. In addition, albumin levels are sometimes inaccurate in cases of underhydration, overhydration, ascites, and nephrotic syndrome.3,4 Table 3 lists additional factors that affect the accuracy of albumin levels.

    Serum albumin increases as inflammation subsides, regardless of how much protein is consumed. Because of its relationship to inflammation, serum albumin is no longer considered a good indicator of malnutrition or protein repletion.3-5Ordering a nutritional or protein supplement due to low albumin is no longer automatic because it is now believed that albumin levels do not reflect nutritional status or refeeding with much accuracy. However, a decreased serum albumin is considered an indicator of morbidity and mortality and persons with low albumin levels are sometimes at nutritional risk for other reasons.