The Role of the Nurse in Nutritional Screening
Nutritional screening is a rapid process performed by healthcare professionals, including nurses, to identify individuals at nutritional risk who may require a more in-depth assessment by a registered dietitian. The primary goal is to facilitate early nutritional intervention, which has been shown to reduce morbidity and mortality, particularly in hospitalized patients. Nurses are at the forefront of this process, often conducting the initial screening upon admission, during transfers, and at regular intervals.
A comprehensive nutritional assessment, in contrast, is a more detailed evaluation performed for patients already identified as being at nutritional risk. It involves a deeper dive into anthropometric measurements, biochemical parameters, clinical evaluation, and dietary history, often guided by the ABCD method (Anthropometric, Biochemical, Clinical, Dietary).
Common Nutritional Screening Tools for Nurses
Several validated screening tools are available for nurses to use, each with slightly different applications depending on the patient's age and clinical setting. Selecting the right tool ensures accuracy and efficiency in the screening process.
1. Malnutrition Universal Screening Tool (MUST)
Developed by the British Association for Parenteral and Enteral Nutrition (BAPEN), MUST is a widely used, five-step tool for identifying adults who are malnourished, at risk of malnutrition, or obese across various care settings, including hospitals and the community. The five steps include:
- Step 1: BMI Score: Calculate the client's BMI. A score of 0 is given for a BMI >20 (>30 obese), 1 for a BMI of 18.5-20, and 2 for a BMI <18.5.
- Step 2: Weight Loss Score: Assess for unplanned weight loss in the last 3-6 months. A score is assigned based on the percentage of weight lost.
- Step 3: Acute Disease Effect Score: Add a score of 2 if there has been or is likely to be no nutritional intake for more than 5 days due to acute illness.
- Step 4: Overall Risk Score: Add the scores from the previous steps to determine the overall risk category (Low, Medium, or High).
- Step 5: Management Guidelines: Develop a care plan based on the risk category.
2. Mini Nutritional Assessment-Short Form (MNA-SF)
The MNA-SF is a quick, six-question tool specifically validated for screening malnutrition risk in older adults (65 and older). It evaluates key indicators including appetite changes, weight loss, mobility, psychological stress or acute disease, and neuropsychological problems. The final score includes an anthropometric measurement, typically BMI or calf circumference if BMI is unavailable. It is the preferred version for clinical use and helps streamline the screening process for the geriatric population.
3. Subjective Global Assessment (SGA)
The SGA is a simple, bedside method often considered a comprehensive assessment tool that can also be used as a screening method. It provides a more subjective, yet accurate, diagnosis of malnutrition by taking a thorough history and performing a focused physical examination. The assessment includes recent changes in food intake, weight changes, gastrointestinal symptoms, and evaluation for loss of muscle mass and subcutaneous fat.
4. Malnutrition Screening Tool (MST)
The MST is a simple, quick-to-administer tool developed in Australia, suitable for hospitalized and ambulatory adult patients. It consists of only two questions regarding weight loss and appetite, making it very efficient for initial screening. The simplicity allows for rapid identification of patients at risk, triggering further assessment.
Comparison of Common Nutritional Screening Tools
| Feature | Malnutrition Universal Screening Tool (MUST) | Mini Nutritional Assessment-Short Form (MNA-SF) | Subjective Global Assessment (SGA) | Malnutrition Screening Tool (MST) |
|---|---|---|---|---|
| Target Population | General adult population | Elderly (aged 65+) | Hospitalized patients, various populations | Hospitalized and ambulatory adults |
| Screening Items | BMI, unplanned weight loss, effect of acute disease | Appetite, weight loss, mobility, stress, BMI/calf circumference | Weight change, dietary intake, GI symptoms, physical exam | Recent weight loss, reduced appetite |
| Time Required | Quick, five-step process | Brief, 6-question tool (approx. 5 min) | More detailed, can take up to 10 min | Very brief, two-question tool |
| Scoring | Numeric score (0-6) categorizing risk as low, medium, or high | Numeric score (max 14) indicating risk level | A (well-nourished), B (moderate malnutrition), C (severe malnutrition) | Numeric score, with high risk indicated by a specific threshold |
| Setting | Hospital, care homes, community | Geriatric clinics, hospitals, nursing homes | Clinical acute settings | Hospital, ambulatory, care homes |
The Nursing Process and Screening Results
Once a nurse has screened a client's nutritional status using an appropriate tool, the results guide the next steps in the nursing process. If a client is identified as being at medium or high risk, the nurse's responsibilities include:
- Assessment: Performing a more focused assessment, documenting dietary intake, and considering underlying medical or social issues.
- Collaboration: Informing the multidisciplinary team, including physicians and, crucially, making a referral to a registered dietitian for a comprehensive assessment and intervention plan.
- Intervention: Implementing initial interventions as per local protocols, which might include diet fortification or nutritional supplements, and patient/family education.
- Monitoring and Evaluation: Recording and monitoring the client's nutritional intake and weight over time and reviewing the care plan regularly.
Conclusion
The selection of which tool would the nurse use to screen a client's nutritional status is a critical decision based on the clinical setting and patient population. Tools such as the MUST, MNA-SF, and MST provide efficient and validated methods for identifying individuals at risk of malnutrition. By utilizing these tools effectively and integrating the results into the nursing care process, nurses play a vital role in preventing and managing malnutrition, ultimately leading to better health outcomes for their clients. A referral to a dietitian is the appropriate next step for anyone identified as high-risk by the screening process.
A Deeper Look at Screening in Specific Contexts
While the primary screening tools are widely used, specific clinical situations may require additional considerations. For instance, in the Intensive Care Unit (ICU), specialized tools like NUTRIC or mNUTRIC might be preferred due to the unique nutritional needs of critically ill patients. Similarly, specialized tools are available for pediatric and oncology populations to address their specific risks. For older adults, factors like dementia, mobility, and multiple medications are incorporated into tools like the MNA-SF to provide a more holistic risk profile. The ongoing assessment and monitoring of at-risk individuals are as important as the initial screen to ensure interventions are effective. The ability of a nurse to accurately select and administer the right tool is a cornerstone of proactive, patient-centered nutritional care. More information on global guidelines for nutritional screening can be found at the European Society for Clinical Nutrition and Metabolism (ESPEN) website.
