Nutritional Assessment

Definition

Nutritional assessment is a comprehensive evaluation done to define a person's nutrition status. Assessment includes gathering information from the person's medical history, dietary history, a physical examination, anthropometric measurements, and laboratory tests.

Purpose

In recent decades, healthcare providers have placed increasing emphasis on the role that nutrition plays in a patient's overall health. They also have recognized the way in which various diseases and conditions affect a person's nutritional status.

Anorexia nervosa, disease, test procedures, surgeries, therapeutic regimens such as chemotherapy and radiation, and some medications can affect dietary intake. The natural aging process also can lead to increased nutritional problems among the elderly. As many as 65% of elderly patients are calorie-protein undernourished when admitted to a hospital or they develop nutritional deficits while in the hospital.

Older adults are at risk for poor nutrition for a number of reasons:

• normal aging changes in the senses of smell and taste
• the effects of chronic diseases on food intake or food utilization
• dental problems and ill-fitting dental appliances that result in difficulty chewing
• depression and other psychological changes
• confusion, memory loss, and dementia
• social isolation
• side effects from multiple medications
• restricted financial resources
• diminished function that subsequently limits their ability to shop or prepare meals

Nursing home patients and cancer patients are among the individuals who most often require ongoing nutritional counseling and intervention. Patients with life-ending illnesses receiving palliative care have special nutrition support needs as well. The nutrition care of these subgroups of patients should be based on careful nutrition assessment.

In addition to increasing the use of nutrition assessment in hospitals, nursing homes, and other facilities caring for patients who are aging or chronically ill, nutrition assessment may be used to help guide the treatment of patients with a number of manageable chronic diseases such as chronic obstructive pulmonary disease (COPD), congestive heart failure, coronary heart disease, diabetes mellitus, and hypertension. Nutrition assessment also plays a role in caring for infants, children, and people who have health or dietary conditions such as anorexia, diabetes, severe food allergies, and obesity.

The emphasis on nutritional assessment and screening has led to the development of new assessment tools, standards, and regulations. For example, the Centers for Medicare and Medicaid Services (CMS), the agency that oversees Medicare, requires long-term care facilities to "conduct initially and periodically a comprehensive, accurate, standardized, reproducible assessment of each resident's functional status." The facility also "must ensure that a resident maintains acceptable parameters of nutritional status, such as body weight and protein levels, unless the resident's clinical conditions demonstrate that this is not possible." The Joint Commission on Accreditation of Healthcare Organization (JCAHO) standards and various state regulations also may require regular assessment or monitoring of a patient's nutrition status.

Precautions

Little agreement exists concerning the best nutrition assessment tools for patients in all subgroups and settings. Healthcare organizations are working on standards and protocols for nutrition assessment, but many of these are still in development. Some nutrition assessment tools are complicated and require careful cooperation of a team of healthcare professionals to complete an accurate patient evaluation.

Nutrition assessment of elderly patients is further complicated by the physiologic and metabolic changes associated with aging. Nutrition assessment involves a combination of examinations and patient history, and as such, no single laboratory test or finding should be used to indicate poor nutrition. Finally, some nutrition assessments rely on patient memory and self-assessment, which may be somewhat problematic if the patient has a condition such as dementia or if one is assessing a young child.

A further concern is that obese patients who are compromised nutritionally may have a severe nutritional deficiency that goes unnoticed if an assessment relies too heavily on markers that aim at the whole-body level, such as body mass index (BMI). This is one reason why registered dietitians emphasize a comprehensive approach to assessment.

Description

There are varying levels of nutritional assessment. A complete nutritional assessment generally is reserved for seriously ill patients, those at high nutritional risk, or individuals with signs of malnutrition. Clinicians may also perform a dietary assessment, which is less involved than a nutritional assessment, but helps ensure adequate nutrition by providing guidance for improving diet.

The nutrition assessment is a complex procedure involving several steps, including obtaining a patient's medical, dietary, and social history, a physical examination, anthropometric measurements, laboratory tests, and evaluation of energy, protein, and fluid requirements.

Patient history

This phase of the nutrition assessment is critical in determining a patient's status and needs. It helps bring to light potential medical or social causes of a patient's nutrition problems. For example, many patients take a variety of vitamins, minerals, non-prescription medications or complementary and alternative therapies without informing their physicians. These substances may not be included in the patient's medical record and only a careful interview with the patient, family members, or other caregiver will reveal this information. The interviewer should also determine the patient's past and current medical conditions, as well as the patient's family history.

Medical conditions that can affect nutrition, particularly among the elderly, include:

• Cancer. Patients of all ages can suffer from cancer anorexia or absence of appetite. Therapies used to treat cancer can cause nausea, diarrhea, and other side effects that affect nutrition, as can some cancers themselves. Cancer cachexia can cause specific nutrition difficulties.
• Chronic obstructive pulmonary disease. As with cancer, many patients with COPD suffer from depression, which may affect their eating habits and nutritional status. Patients may not be able to eat large meals. Some medications cause loss of appetite or nausea; others cause weight gain.
• Congestive heart failure. Patients may have unrecognized cardiac cachexia. Medications may lead to electrolyte imbalances, anorexia, and nausea. Many patients may not be physically active as a result of this disease.
• Coronary heart disease. Many patients with coronary heart disease have a dietary history of high cholesterol and/or high fat and calorie intake. They also may have type 2 diabetes or a pre-diabetic condition. These patients need help maintaining a healthy weight and diet as they are at risk for a number of complications, including nutritional side effects from medications such as nausea, elevated liver enzymes, and gastric distress.
• Dementia. Nearly 50% of all people age 85 and older have Alzh eimer's disease or dementia. They may have difficulty preparing food and remembering what they have eaten. Nutritional problems may also be caused by nausea and diarrhea from commonly prescribed medications. Patients with advanced disease need assistance with food choices and daily feeding.
• Diabetes mellitus. About 16 million Americans have type 2 diabetes. Changes in diet are a major part of their treatment. Improper management of this disease can lead to severe complications.
• Hypertension. Nearly one in four Americans has hypertension. Those who use diuretics may see negative nutritional effects secondary to a depletion of sodium, calcium, magnesium, and/or potassium. Maintaining optimal weight and regulating intake of these substances is critical to controlling hypertension.

Many other conditions and diseases can affect a person's nutritional status, particularly when he or she is at high risk of for malnutrition. In an acute care setting, chronic pain or recent trauma from surgery or injury can lead to rapid weight loss or malnutrition. A patient may have an esophageal or gastric obstruction that impairs food transit, or have a history of chronic alcoholism, severe depression, acquired immunodeficiency syndrome (AIDS ), or chronic renal disease. In some cases, a combination of factors lead to the nutritional problems.

The patient history also should include a dietary and social history. The clinician will need to assess the person's recent diet. Depression can exist in conjunction with most of the conditions and diseases listed above. Depression and the medications prescribed to treat it can affect a person's appetite. If an elderly patient lives alone and has physical or transportation limitations, this may affect his or her ability to shop for and prepare food. Some patients may have involuntary diet restrictions due to poverty, abuse, or caregiver ignorance.

Physical examination

The examination consists of measuring the patient's unclothed weight, and if possible, comparing it to previous measurements to determine weight gain or loss. Weight and height measurement can be used to calculated body mass index. Tables are available that can help provide quick assessment of height and weight to rapidly assign BMI.

During a physical examination, the clinician may look for signs of malnutrition such as dull, brittle hair, brittle nails, and scaling skin. These may be the result of specific nutritional deficiencies.

Anthropometric measurements

These measurements may not be reliable over time, but can be helpful when used in initial assessment of the patient's nutritional status. Skinfold measurements provide an approximate measure of subcutaneous fat stores. Skinfold measurements are obtained using special calipers and a tape measure and are usually are taken from the triceps area. Measuring arm and arm muscle circumference can provide data about muscle mass and subcutaneous fat. Waist-to-hip ratios may also be used to evaluate abdominal fat.

Laboratory tests

The nutritional assessment involves use of specific laboratory tests. The most widely used of these is the measurement of serum albumin. Albumin is a protein that when found in low levels (hypoalbuminemia) in the blood may indicate poor nutritional status. Hypoalbuminemia has been associated with high mortality and high morbidity in some patient populations. Serum albumin should not be used as the sole measurement to indicate malnutrition. Depending on the nutritional concern, laboratory tests for pre-albumin, cholesterol, lipoproteins, triglycerides, hemoglobin, hematocrit, or iron, also may be included in the evaluation. These tests involve the drawing of a blood sample, sometimes after a period of fasting.

Nutrition risk screening tools

To further determine specific diet and intake information, the clinician may employ a nutrition risk screening tool. Several tools have been developed for this purpose. They include:

• Mini Nutritional Assessment (MNA). This tool assigns point scores to information from the physical examination, anthropometric measurements, and questions asked of the patient concerning intake of fruits and vegetables, mode of feeding, use of prescription drugs, mobility, and other findings.
• Mini Nutritional Assessment Short Form (MNASF). This consists of only six questions and the BMI calculation. It is a quick method of assessing malnutrition risk. The short form is designed to cover broad aspects of a patient's weight changes, mobility, food intake, and psychological stress.
• Malnutrition Screening Tool (MST). This tool was developed for rapid assessment of adults in acute care settings. Data focus on recent weight changes and food intake prior to hospitalization.
• Malnutrition Universal Screening Tool (MUST). Also used for inpatients, MUST requires clinical judgment concerning a patient's ability to eat while in the hospital.

Nutrition assessment tools

Some tools used to screen for malnutrition or other nutrition-related conditions also may be used in a nutritional assessment. For example, the MNA, which was developed as a screening tool for people in outpatient settings, has evolved into a nutrition assessment tool. The Subjective Global Assessment (SGA) was developed to evaluate the nutritional status of surgical patients. The Prognostic Inflammatory Nutrition Indicator (PINI) may be helpful in using laboratory values to predict which older adult inpatients need long-term care based on nutrition indicators. Development of reliable tools is still underway, as is evaluation of these tools for use in various populations.

Preparation

Before completing a nutrition assessment, the patient will need to have laboratory tests performed. Some of the laboratory tests may require fasting or other preparation as directed by the physician ordering the tests.

Aftercare

Nutritional assessment requires no aftercare except follow-up on results and recommendations. Patients may be instructed on how to care for the blood drawing site where possible bruising may develop.

Complications

There are some small risks when drawing blood for the laboratory tests. These risks should be considered based on an individual patient's status when setting up the nutritional assessment. Cancer patients, for example, may face a higher risk of infection at the site where blood is drawn because their immune systems are compromised.

Results

The normal BMI ranges from 24 to 27 kg/m². A BMI of less than 20 combined with unintentional weight loss of more than 5% suggests nutritional support is needed, as does a BMI of less than 18.5 or unintentional loss of more than 10% of body weight in the previous three to six months. Anthropometric values below the tenth percentile for a person's age group should prompt concern about malnutrition. Other measurements may indicate nutrition problems such as obesity. For example, a waist-to-hip ratio greater than 1.0 in males and 0.8 in females can indicate central obesity, increasing risk for diabetes and coronary heart disease.

Physical signs of malnutrition may include hair thinning, easily bruised skin, decreased skin fold thickness, conjunctival pallor, coarse skin, goose bumps (cutis anserina), and lower extremity rashes.

Serum albumin levels below 3.5g/dL may be a cause for concern. Serum cholesterol below 160mg/dL or above 240mg/dL indicate that nutritional intervention may be necessary. Other laboratory values may be used to detect underlying conditions such as triglycerides and C-reactive protein measurement for coronary heart disease or blood pressure over 120/80 mm Hg for diabetes mellitus.

KEY TERMS

Anorexia nervosa— A psychiatric disorder in which the individual intentionally starves him or herself.

Anthropometric measurements— Comparative body measurements such as height, weight, and percent body fat as determined by skin folds or hydrostatic weighing.

Cachexia— Wasting with anorexia, abnormal metabolism and negative balance of energy that is disproportionate to nutrient intake. This occurs in many cancer or otherwise chronically ill patients.

Palliative— Intended to control pain and make the patient more comfortable when a cure is not possible.

Screening and assessment tools provide forms with distinct areas in which the clinician will record all relative results from interviews, measurements, physical examination, and laboratory findings. These results then can be assessed and/or assigned point values that are added for a final score. For example, the MNA provides levels for evaluation. A sum score above 23.5 represents satisfactory nutritional status; a score of 17 to 23.5 represents malnutrition risk with good prognosis if the patient is given early intervention. A score below 17 means the patient has protein energy malnutrition, requiring immediate consideration of intervention and further nutrition assessment.

Healthcare team roles

Physicians are responsible for assessing, diagnosing, and treating conditions associated with or contributing to poor nutrition status, and working with registered dietitians to develop a nutrition care plan. Registered dietitians provide medical nutrition therapy to patients and tailor the therapy to individual patient needs. They also advise patients, family, and other caregivers on medical nutrition.

Actually ensuring that patients in acute and long-term care settings are appropriately fed normally is the responsibility of the nurses and nurse aides caring for them. It takes a cooperative effort of physicians, nurses, and dietitians to adequately assess patients for nutrition in these settings. Increasingly, nurses are making the patient's nutritional status a priority and are involving the patient's family members assisting the patient in following dietary guidelines.

Resources

BOOKS

Dharmarajan, T.S., and Ajit J. Kokkat. "Geriatric Nutrition," in Clinical Geriatrics, ed. T.S. Dharmarajan and Robert A. Norman. New York: Parthenon Publishing, 2003, 93-104.

Sullivan, Dennis H., and Larry E. Johnson. "Nutrition and Aging," in Principles of Geriatric Medicine and Gerontology, William R. Hazard, et al., eds. New York: McGraw-Hill, 2003, 1151-1170.

PERIODICALS

Booth, Joanne, Alex Ledbetter, Morag Francis, et al. "Implementing a Best Practice Statement in Nutrition for Frail Older People: Part 1." Nursing Older People (Feb. 2005): 26-29.

"Care and Treatment of Residents." Healthcare Food & Nutrition Focus (Dec. 2002): 7-11.

Edwards, Douglas J. "Nutrition: Making Up for Hospital Shortfalls." Nursing Homes (April 2002): 9-10.

Hoban, Victoria. "Improving Patient Nutrition." Nursing Times (June 7, 2005): 18-20.

"Identifying Patients at Risk; ADA's Definitions for Nutrition Screening and Nutrition Assessment." Journal of the American Dietetic Association (Aug. 1994): 838-839.

"Independent Nurse: Screen New Patients for Undernutrition." GP (May 20, 2005): 2.

Jackson, Rita. "Assessment of Residents." Healthcare Food & Nutrition Focus (June 2002): 1-6.

Jackson, Rita. "Troubleshooting Your Care Plans: Improving the Quality of Nutrition Care in LTC." Healthcare Food & Nutrition Focus (Aug. 2002): 1-7.

Lee, Virginia K. "Problems With Eating and Nutrition: Geriatric Self-learning Module." Medsurg Nursing (Dec. 2004): 405-408.

"Pitfalls of Nutritional Screening in Injured Obese Patients Outlined." Obesity, Fitness & Wellness Week (Nov. 27, 2004): 15.

ORGANIZATIONS

American Dietetic Association. 216 West Jackson Blvd., Chicago, IL 60606. (800)366-1655. http://www.eatright.org.

Nutrition Screening Initiative. 1010 Wisconsin Avenue, NW, Suite 800, Washington, DC 20007. (202)625-1662. http://www.aafp.org/nsi.xml.

OTHER

Charney, Pamela. "Nutrition Screening and Assessment in Older Adults." Today's Dietitian 2005. http://www.todaysdietitian.com/archives/td_0505p10.shtml. (May 2005).

"Clinical Evaluation of the Malnourished Patient." McGraw-Hill's Access Medicine, Harrison's Online 2005. http://www.accessmedicine.com.

A Physician's Guide to Nutrition in Chronic Disease Management for Older Adults. 2005. http://www.aafp.org/x16105.xml.