The proteins most often used in nutrition assessment include albumin, prealbumin (PAB), C-reactive protein, and retinol-binding protein. When used in combination, they can very accurately reflect a subclinical deficit and assess response to restorative therapy.

For years, albumin was the widely accepted marker for malnutrition. However, mounting evidence points to PAB as the better choice. Because albumin has a half-life of 21 days, it is slow to respond to a patient’s recent increase in nutrients and, therefore, is not a good indicator of recent changes in protein levels. In contrast, PAB responds more rapidly and gives a timelier picture of a change in dietary status. Because of its short half-life (2 days), PAB responds quickly to a decrease in nutritional intake and nutritional restoration. It reflects the current nutritional status within a patient’s body, not the status from 3 weeks ago.

Adults: 19–38 mg/dL or 190–380 mg/L

Younger than 18 years: 12–32 mg/dL or 120–320 mg/L

1. Collect a 7-mL blood serum sample in a red-topped tube. Observe standard precautions.

2. Label the specimen with the patient’s name, date and time of collection, and test(s) ordered. Place the specimen in a biohazard bag for transport to the laboratory.

1. Hospital laboratories, in conjunction with dietitians, administration, pharmacists, nurses, primary providers, and other healthcare providers, may develop a clinical pathway that includes running a PAB upon admission of each surgical, ICU, and medical patient.

2. Values of 0–5, 5–10, and 10–15 mg/dL (0–50, 50–100, and 100–150 mg/L) indicate severe, moderate, and mild protein depletion, respectively.

Pretest Patient Care

1. Explain test purpose. PAB is useful in assessing nutritional status, especially in monitoring the response to nutritional support in the acutely ill patient.

2. Follow guidelines in Chapter 1 regarding safe, effective, informed, pretest care.