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Part II Nutrition Assessment, Consequences, and Implications

2. Is the test cost-effective? Managed care man- dates cost-effectiveness. Laboratory tests must be cost-effective.

Example: Albumin and prealbumin tests indicate both early depletion of protein stores and reple- tion of protein stores once an intervention program has begun. The half-life of prealbumin is 2 to 3 days; for albumin, it is 18 to 21 days. After an MNT intervention program has begun, it takes at least 3 weeks in adults (and longer in older adults) to see an improvement in the albumin (6). In managed care with an expected short-term stay, the prealbumin may be a more cost-effective measure because it identifies the change in protein status earlier than the albumin. With the extended-care client, the primary concern is to reduce the risk of pressure ulcers, with early risk assessment and appropriate nursing and nutrition intervention (1).

3. Is the nutrition goal for the client consistent with treatment goals and advance directives?

Example: An 85-year-old woman with a hemoglo- bin level of 9 g/dL may not be interested in improv- ing her iron status through an MNT intervention program followed by a reevaluation of her iron status. The low-iron status may be secondary to anemia of chronic disease, where the body is unable to use dietary or supplemental iron. In this case, the iron supplement would be neither nutri- tionally beneficial nor cost-effective. Putting the client on an oral daily supplement for 3 months and then rechecking the iron level in 90 days may not be consistent with treatment goals (1).

CLINICAL LABORATORY VALUES The system for reporting clinical data is in transition. Most health care professionals learned the conven- tional units for each laboratory test. Many laboratories continue to use conventional units in their summary reports. Laboratory values may be converted from one system to another by using the unique conversion factor for each laboratory test (1).

“The preferred method for reporting clinical labo- ratory data is in terms of international units (SI units). SI units is an abbreviation for Système International d’Unités, or International System of Units. The reason for the change to SI units is to have an international standard for reporting research and medical data” (1). Laboratory values are provided in both conventional and SI units.

LABORATORY TESTS USED FOR

NUTRITION ASSESSMENT Commonly used laboratory tests ordered to evaluate nutritional status are included in tables. Summary charts for laboratory test results reflecting protein status, anemias, and risk for chronic diseases are found in Tables 16.2, 16.3, and 16.4 (see pages 217–218) (1,5). Values listed for “adults” typically refer to persons 25 to 59 years of age. Values listed for “older adults” refer to individuals older than 60 years.

Alanine Aminotransferase

Normal Values ●

●

Adult: 4 to 36 IU/L; 4 to 36 U/L (SI) (5) Older adult: slightly higher than adults (5)

Nutritional Significance Alanine aminotransferase (ALT; formerly called serum glutamic oxaloacetic transaminase is an enzyme found primarily in the liver and to a lesser degree in the kidneys, heart, and skeletal muscle. Injury to the liver results in elevated levels of ALT. Serum aspartate aminotransferase (AST) levels are often compared with ALT. An AST:ALT ratio greater than 1 is seen in alcoholic cirrhosis, liver congestion, and metastatic tumor of the liver. The AST:ALT ratio less than 1 is seen in acute hepatitis, viral hepatitis, and infectious mononucleosis (1). ALT levels increase with:

●

hepatocellular disease hepatitis

➤ ➤ ➤ ●

cirrhosis or necrosis tumor

cholestasis ● ● ● ● ● ● ● ● ● ●

The following drugs may increase ALT levels (1): acetaminophen allopurinol aspirin

cephalosporins clofibrate codeine

indomethacin isoniazid (INH) methotrexate tetracycline