From the Guidelines
The most accurate measure of adequacy of nutritional support is serum prealbumin level (option d). According to the most recent and highest quality study 1, plasma albumin and transthyretin/pre-albumin concentrations may be used mainly to indicate and monitor catabolic activity, but their validity as nutrition indicators is low due to perturbation by inflammation. However, prealbumin has a short half-life of approximately 2-3 days, making it highly responsive to recent changes in nutritional status, as noted in 1. This allows healthcare providers to quickly assess the effectiveness of nutritional interventions. Unlike serum albumin, which has a longer half-life of about 20 days and can be affected by many non-nutritional factors like inflammation and liver disease, prealbumin provides a more immediate reflection of protein synthesis and nutritional adequacy.
Key Points to Consider
- Body weight and triceps skinfold measurements are useful anthropometric measures but can be influenced by fluid status and don't specifically reflect recent protein synthesis.
- When monitoring nutritional support, prealbumin levels should be checked regularly, with increasing levels indicating adequate nutritional support and protein synthesis, while decreasing levels suggest inadequate nutrition that may require adjustment of the nutritional plan.
- The ESPEN guidelines on definitions and terminology of clinical nutrition 1 emphasize the importance of monitoring nutrition therapy to check and adjust that nutrition delivery is in progress and nutrition intake or provision is sufficient.
- Other studies, such as 1, focus on the importance of nutritional therapy in cancer patients, but do not provide direct evidence for the most accurate measure of adequacy of nutritional support.
Monitoring Nutritional Support
- Regular assessment of the functional consequences of the illness and the malnutrition is crucial, as recommended in 1.
- Prealbumin concentration is the quickest means of detecting nutritional improvement, making it a valuable tool in monitoring nutritional support.
From the Research
Measures of Nutritional Support
The most accurate measure of adequacy of nutritional support can be determined by evaluating various nutritional markers. The options provided are:
- Serum albumin level
- Body weight
- Triceps skinfold measurement
- Serum prealbumin level
Evaluation of Options
Based on the available evidence, the following points can be considered:
- Serum prealbumin level is considered a sensitive predictor of clinical outcomes and a quality marker for nutrition support 2.
- Prealbumin has been proposed as a useful nutrition biomarker for the assessment of patients at nutrition risk due to its shorter half-life compared to albumin 3.
- Serum prealbumin concentrations have been shown to be associated with higher all-cause mortality rates and can improve the prognostic value of nutritional risk screening scores 3.
- Dynamic changes in prealbumin levels can be used to estimate the effectiveness of nutrition support in critically ill patients 2.
- Prealbumin can complement clinical history, anthropometric assessment, and physical examination to assess malnutrition with more certainty 4.
- Prealbumin serum concentrations have been shown to be a useful tool in the assessment of malnutrition in hospitalized patients, with a good sensitivity and specificity profile 5.
Comparison of Options
In comparison to other options, serum prealbumin level has been shown to be a more sensitive and reliable marker of nutritional status. For example, serum albumin and prealbumin levels have been found to remain normal in otherwise healthy subjects despite marked nutrient deprivation until extreme starvation 6. Therefore, based on the available evidence, serum prealbumin level appears to be the most accurate measure of adequacy of nutritional support.