Importance of Nutritional Assessment
The Importance of Early Diagnosis in Effective Nutrition Management
Nutritional assessment is typically defined as “a comprehensive approach to determining nutritional status using medical, nutritional, and medication histories; physical examination, anthropometric measurements and laboratory data.”1,2,3
If nutritional risk screening reveals a patient being nutritionally at risk for malnutrition, a more in-depth evaluation of the causes of disease-related malnutrition should be conducted. Nutritional assessment is crucial to fully understand the patient’s condition and to develop a specific nutrition care plan.
Parameters of a Nutritional Assessment: What Physician Should Look For
Relevant assessment parameters should be evaluated in detail to assess the nutritional status and the risk for malnutrition. Biochemical paramaters are useful, objective, and readily available for this assessment:4,5
- Albumin: A tracking parameter for long-term interventions; direct negative correlation with mortality and rate of complications; liver function disorders, post-aggression metabolism, proteinuric nephropathy, protein-losing enteropathy. Nutrition deficit is detected only if protein deficiency already exists over a long time, due to long half-life of albumin.4 Albumin is not very sensitive in malnutrition, because it is also low in acute stress, infections, surgery and polytrauma.
- Transferrin: A tracking parameter for short-term interventions; no clear correlation with outcome; also low in anemia, liver diseases and certain antibiotic therapies. Transferrin may be a better and more sensitive reflection of nutritional status compared to albumin.
- Pre-albumin (transthyretin) (TTR): A tracking parameter for short-term monitoring of nutritional interventions. Pre-albumin may be a better and more sensitive reflection of nutritional status compared to albumin, and allows identification of malnutrition at an early stage.
- Retinol-binding protein (RBP): A tracking parameter which is increased in limited kidney function and is also used for identification of malnutrition at an early stage. However, it is only suitable only for short-term monitoring.
Other relevant assessment parameters, which should be evaluated in detail, include disease and treatment-related risk factors such as nausea, dehydration, diarrhea, acute infections; social and psychosocial risk factors such as depression and social isolation; and nutrition-related risk factors such as allergies, anthropometric aspects and restrictive diets.
Subjective Global Assessment
Subjective Global Assessment (SGA) is a nutritional non-invasive assessment tool that has been found to be highly predictive of nutrition-associated complications. SGA considers not only alterations in body composition, but also changes in physiological function. The SGA should be performed considering the following factors:1,2,6,7,8,9
- Clinical considerations of disease-related effects: e.g., the impact of surgery, treatment, medication etc.
- Physical signs of malnutrition: e.g. their physical and psychosocial state, loss of subcutaneous fat or muscle mass, breathlessness, mobility, edema, poor wound healing, etc.
- Dietary aspects: e.g., recent and past diet and fluid history, influencing factors, nutritional requirements.
- Anthropometric measurements: e.g., body weight and composition (BMI, muscle mass, body water, fat and fat-free mass), as well as hand grip strength.
- Biochemical and hematological markers: e.g., deviations from normal results regarding a full blood count, urea and electrolytes, liver and renal function tests.
If a patient receives an SGA “A” rating, they are considered well nourished. An SGA “B” rating indicates a moderately malnourished patient. And an SGA “C” rating reflects a severely malnourished patient.
- 1. a. b. No authors listed. Identifying patients at risk: ADA's definitions for nutrition screening and nutrition assessment. Council on Practice (COP) Quality Management Committee. J Am Diet Assoc 1994;94:838-839.
- 2. a. b. Thomas B, Bishop J (Eds). Manual of Dietetic Practice, 4th ed., Oxford: Wiley Blackwell 2007.
- 3. Barker LA, Gout BS, Crowe TC. Hospital malnutrition: prevalence, identification and impact on patients and healthcare system. Int J Environ Res Public Health 2011;8(2):514-527.
- 4. a. b. ondrup J, Allison SP, Elia M et al. ESPEN Guidelines for Nutrition Screening 2002. Clin Nutr 2003;22(4):415–421.
- 5. Schutz Y. Assessment of Nutritional Status. In: Biesalski HK, Fürst P, Kasper H et al., editors. Nutritional Medicine. Stuttgart: Thieme 2004:19-27.
- 6. Barker LAGout BS, Crowe TC. Hospital malnutrition: prevalence, identification and impact on patients and the healthcare system. Int J Environ Res Public Health 2011;8:8514-8527.
- 7. Barbosa-Silva MC, Barros AJ. Indications and limitations of the use of the subjective global assessment in clinical practice: an update. Curr Opin Clin Nutr Metab Care 2006;9(3):264-269.
- 8. Keith JN. Bedside nutrition assessment past, present, and future: a review of the Subjective Global Assessment. Nutr Clin Pract 2008;23(4):410-416.
- 9. Detsky AS, McLaughlin JR, Baker JP et al. What is subjective global assessment of nutritional status? JPEN 1987;11(1):8-13.