American Association of Critical-Care Nurses (AACN) Certification Practice Test

Which marker reflects a patient's nutritional status for the previous 1-2 months?

1. Serum creatinine

2. Serum albumin

3. Serum prealbumin

4. Serum transferrin

The correct answer is: Serum albumin

Serum albumin is a crucial marker for assessing a patient's nutritional status over the previous 1-2 months due to its longer half-life, typically around 20 days. It provides insight into the protein status of an individual and is often used to gauge chronic malnutrition. A decrease in serum albumin levels can indicate protein deficiency or a chronic inflammatory state affecting nutrition. It is synthesized in the liver, and low levels can also reflect liver dysfunction or other systemic illnesses that might impact nutritional absorption and metabolism. While other markers like serum prealbumin and serum transferrin can also provide information about nutritional status, they reflect more acute changes. For example, prealbumin has a shorter half-life of about 2-3 days, making it more sensitive to recent changes in nutritional intake but less reliable for chronic assessments. Serum transferrin, while helpful in assessing iron deficiency and protein status, is also influenced by acute inflammatory responses, making it less reliable for a direct measure of nutritional status over a 1-2 month period. Therefore, for a long-term evaluation (1-2 months) of a patient's nutritional status, serum albumin is the most appropriate choice.