Plasma proteins, such as albumin, prealbumin, transferrin, ferritin and retinol binding protein, have all been used as nutritional markers (Table 1.1). In the past 30 years, there have been over 20,000 citations
on albumin . One-third of albumin is maintained in the intravascular compartment and two-thirds in the extravascular compartment. Serum albumin levels are a representation of both liver albumin synthesis and albumin degradation or losses. The serum concentrations of albumin
Serum protein half lives
18 days 8 days 2-3 days 2 days 20 hours and other plasma proteins are affected by a patient's total body water status, liver function and renal losses. Although purported as reliable nutritional markers, serum proteins are best considered markers of a patient's overall health status rather than a true nutritional marker. Reinhardt and associates demonstrated a linear correlation between the degree of hypoalbuminemia and the 30-day mortality rate in hospitalized patients . An increase in hospital mortality was also seen in geriatric patients with low serum albumins undergoing cardiovascular surgery . Careful studies have shown serum albumin to be a less sensitive indicator of a patient's nutritional status as compared to clinical judgment based on a patient's medical history and physical examination .
Direct measurements of body functions can be used as markers of the degree and significance of malnutrition. For example, skeletal muscle function can be rapidly affected by malnutrition regardless of other major disease processes such as sepsis, trauma or renal failure .
In critically ill patients who are not able to follow commands, bedside muscle function can still be tested. Stimulation of the ulnar nerve at the wrist with measurement of contraction of the abductor pollicus longus has been standardized . Force-frequency curves have been recorded in controls and standardized.
In the patient who is able to follow commands, muscle mass can be determined from handgrip strength by the use of a bedside tool known as a handgrip dynamometer (Fig. 1.4). Hospitalized patients with poor grip strength have been shown to have an increase in hospital length of stay, reduced ability to return home and increased mortality .
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WHAT IT IS A three-phase plan that has been likened to the low-carbohydrate Atkins program because during the first two weeks, South Beach eliminates most carbs, including bread, pasta, potatoes, fruit and most dairy products. In PHASE 2, healthy carbs, including most fruits, whole grains and dairy products are gradually reintroduced, but processed carbs such as bagels, cookies, cornflakes, regular pasta and rice cakes remain on the list of foods to avoid or eat rarely.