Prealbumin Testing for Malnutrition Detection
Identifying Malnutrition in Time to Make a Difference
by Cindy Mulder MS, MSN, RNC, CNP
APPROXIMATELY 30% TO 60% of hospitalized patients have protein-calorie malnutrition (PCM)—a condition that increases the time needed to recover from injuries, raises the number of complications, and lengthens hospital stay. But early detection of nutritional deficiencies can improve patient outcomes and decrease healthcare costs.
The Prealbumin Advantage
For years, assessing nutritional status meant measuring a patient’s albumin level. But albumin has a half-life of 20 days, so the albumin level changes slowly in response to reduced protein intake. While that makes albumin a good indicator of chronic malnutrition, it means it’s not a good tool for identifying patients at risk for PCM or for monitoring the short-term effects of nutritional therapy.
Detecting acute changes in nutritional status requires a serum prealbumin level. A protein produced primarily in the liver but also in the GI mucosa, prealbumin is a sensitive malnutrition marker. Because its half-life is just 2 days, its serum level reflects rapid changes in visceral protein status.
Time for Testing
If your initial nutritional assessment reveals the patient has a risk of PCM, prealbumin testing should be done. Patients at risk include those who:
- are age 65 and older
- haven’t eaten for 5 days or more before admission
- have a history of having lost 20% or more of their usual weight
- have a chronic debilitating condition
- have a serum albumin level below 2.8 g/dL
- are receiving parenteral or enteral nutrition.
Prealbumin levels also may be measured to monitor the protein nutritional status of patients who have undergone gastric bypass surgery. These patients are prone to PCM because of decreased stomach size and reduced nutrient absorption.
What the Levels Mean
A normal prealbumin level is 15 to 35 mg/dL. Levels between 11 and 15 mg/dL indicate a high risk and warrant twice-weekly measurement of prealbumin levels.
A patient with a prealbumin level below 11 mg/dL needs aggressive nutrition therapy, such as enteral feedings or total parenteral nutrition. The goal is to increase the prealbumin level by 2 mg/dL a day. A rise of less than 4 mg/dL in 8 days indicates a poor prognosis. If the level isn’t rising fast enough, reassess the patient’s nutritional regimen. If the prealbumin level is increasing as expected, the patient probably is getting at least 65% of his or her protein and energy requirements. (See What makes prealbumin levels go up and down.)
Recognizing PCM early and starting nutrition thera- py reduces morbidity, mortality, and healthcare costs. The prealbumin test is inexpensive and results give a more accurate picture of acutechanges.
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Cindy Mulder is Associate Professor in the Department of Nursing, School of Health Sciences, at the University of South Dakota in Sioux Falls.