MALNUTRITION

In geriatric rehabilitation, malnutrition affects a patient's functional status and global medical condition. Malnutrition occurs when a deficiency of caloric, vitamin, mineral, protein, water, and/or nutrient uptake is present.

Alternatively, malnutrition can be thought of as a BMI greater than 27. However, no exact definition of malnutrition has been established in the elderly.

Malnutrition can decrease one's resistance to infection and result in poor wound healing. Malnutrition can also lead to increased skin fragility, osteoporosis, anemia, diabetes, and cardiovascular disease.

Again, although no exact definition exists, the following findings are associated with the diagnosis: involuntary weight loss (>15 lb over 6 mo, >12 lb in 3 mo, or > 9 lb in 1 mo), BMI less than 20 or more than 27, hypoalbuminemia (<3.5 g/dL), hypocholesterolemia (<160 mg/dL), and vitamin or micronutrient deficiency.

Dietary intake of less than 75% at most meals can also be an indicator.

The Food and Nutrition Board of the United States has recommended daily allowances (RDAs) for those older than 51 years, but no formal guidelines have been established for the geriatric population older than 65 years.

RISK FACTORS FOR MALNUTRITION

Physiologic factors of aging may lead to malnutrition. These factors are reduced metabolic requirements, decreased total body protein level, decreased total body water, decreased BMD, decreased taste and smell sensation, diminished levels of neurotransmitters that increase appetite, and early satiety.

Physical conditions include reduced physical activity; poor dentition; digestive disorders; and functional disability that interfere with activities such as grocery shopping, preparing meals, or going out to dine.

A speech language pathologist can assess the patient for dysphagia and aspiration risk by evaluating the individual's oral motor swallowing skills with a clinical swallow study and/or a video fluoroscopic swallow study (VFSS).

Psychological factors that contribute to poor nutritional status in the elderly are depressive symptoms, bereavement, loneliness, and cognitive decline, all of which can affect appetite.

Social barriers include financial limitations, living alone, or relying on others for meals. Other issues to assess when malnutrition is suspected are dietary restrictions, cultural rituals, and alcohol intake.

ASSESSMENT OF MALNUTRITION

The patient's dietary history should include information about the following: consistency of the diet, number of skipped meals, alcohol use, use of nutritional supplements, use of vitamin supplements, use of medications that affect appetite or nutrients, and food preferences to improve caloric intake.

Nutritional screening by a dietitian should be emphasized in accordance with rehabilitation to promote and improve functional outcomes as well as wound healing.

The rehabilitation nurse commonly records the Braden scale score, an assessment of the risk of skin breakdown, which is a result of poor nutrition. Cells become fragile as a result of an inability to sustain metabolism.

Pressure points, especially bony prominences (eg, sacrum, ischial tuberosity), are prone to pressure sores in a state of malnutrition. The Braden scale score should be incorporated along with the patient's overall nutritional assessment.

Height and weight should be recorded at every outpatient visit, and they should be monitored closely while the patient is in the rehabilitation unit. This information is critical for the dietitian or nutritionist to know so that they can properly evaluate the degree of obesity or undernutrition.

Caloric restriction, weight loss, and decreases in blood lipid levels with antihyperlipidemic agents can improve the patient's functional status and serve as preventive cardioprotection in the obese elderly patient. Decreasing height may also suggest osteoporosis and thus be an indication for treatment and fall prevention.

Physical signs that can suggest malnutrition include thinning of enamel on teeth, thinning of the hair, ecchymoses, angular stomatitis, spoon nails, dermatitis, petechiae, pallor, edema, bleeding gums, and glossitis. Peripheral neuropathy and dementia can also be a sign of nutritional deficiency in the elderly.

Serum protein levels may decrease with trauma or infection, but good indicators of malnutrition are albumin levels (half-life, 18-20 d) and prealbumin levels (half-life of 48 h); these are used to monitor nutritional status. The elderly are at risk for marginal deficiencies of vitamins and trace elements.

Many older adults consume small amounts of vitamins B-6, B-12, and D, as well as folate, calcium, magnesium, and zinc. A multivitamin with other necessary supplements can be helpful. Selenium can also be supplemented for wound healing in severely malnourished patients.

Hemoglobin (Hb) concentrations should be obtained to rule out anemia from pathologic processes such as iron deficiency anemia or anemia of chronic disease.

The search for an underlying cause should begin when the Hb level is less than 13 g/dL in men and 11 g/dL in women. In men and women older than 90 years, a level of 11 g/dL is adequate.

The mean corpuscular volume (MCV) should help in detecting vitamin B-12 and folate deficiency. Vitamin B-12 levels should be obtained if deficiency is clinically suspected.

Vitamin D and ionized calcium levels can aid in determining if supplementation is needed to prevent osteoporosis. This determination is especially important in housebound elderly patients who are likely to have vitamin D deficiency.

ENERGY REQUIREMENTS OF THE ELDERLY

Energy intake decreases with age, partly because of a lower metabolic rate associated with decreased physical activity. About 16% of the geriatric population eats less than 1000 kcal/d.

For geriatric patients, recommended daily intake is 25 - 35 kcal/kg.

Complex carbohydrates should make up 55 - 60% of the diet to help meet the patient's fiber, vitamin, and mineral needs.

A daily fiber intake of 20 - 30 g is recommended for older adults to help prevent constipation, to lower cholesterol levels, and to decrease the risk of colon cancer.

Protein should be increased to 15 - 20% of the diet in undernourished elderly patients, especially postoperative patients, patients with trauma, patients with pressure sores, and those with active infections.

Fat calories should account for 10 - 30% of the daily caloric intake; however, fat requirements are not standardized for the elderly. The rehabilitation dietitian should monitor the daily calorie count in malnourished patients, taking all these factors into account.

TREATMENT OF MALNUTRITION

Lactose-free oral and enteral products have excellent nutritional value and are usually well tolerated by the geriatric population.

The most common problem is diarrhea.

The following products provide high protein levels, water, electrolytes, and calorie supplementation :

§ Oral low-residue formulas (Eg: Boost, Ensure)

§ Oral clear liquids (Eg: Resource)

§ Diabetic formulas (Eg: Choice DM, Glucerna)

§ Enteral low residue formulas (Eg: Osmolite, Nutren)

§ Enteral high-fiber formulas (Eg: Jevity)

Approximately 5-30% of those receiving tube feedings experience diarrhea. This effect may be due to the lactose content of the formula, the osmolality of the formula, the rate of delivery, or impaired absorption.

To prevent aspiration, the head of the patient's bed should be maintained at 30° elevation during and for 2 hours after tube feedings. Total parenteral nutrition (TPN) is a more temporary method for achieving adequate nutrition in malnourished patients.

The most common cause of fluid and electrolyte disturbances in the geriatric population is dehydration.

Physiologic reasons for decreased fluid intake and increased fluid loss include the following :

§ A decreased ability to concentrate urine after fluid deprivation

§ An altered thirst sensation

§ Decreased renin activity

§ Decreased aldosterone secretion

§ Increased renal resistance to vasopressin

Isotonic dehydration is attributed to the loss of water and sodium, most commonly due to fasting, vomiting, or diarrhea.

Hypertonic dehydration occurs when water depletion exceeds sodium depletion (serum sodium level >145 mmol/L and serum osmolality >300 mmol/kg); this type of dehydration is exemplified by fever with the loss of water through the lungs and skin and a decrease in oral fluid intake.

Hypotonic dehydration occurs when sodium depletion exceeds water depletion (serum sodium level <135 mmol/L and serum osmolality <280 mmol/kg); this occurs with excessive use of diuretics.

Significant consequences of dehydration are changes in mental status, functional status, orthostatic hypotension, and medication sensitivity. These changes affect the rehabilitation process and can also predispose the patient to falls.

Beside fluid replacement, treatment involves the use of fans, air conditioning, oral fluid intake of 1500-2500 mL/d) for those without cardiac or renal disease, daily monitoring of the patient's weight, monitoring of orthostatic blood pressures, and a review of the patient's current medications. Fluid requirements also increase with the use of air-mattress systems.

The social worker has an important role in helping the geriatric patient achieve a better nutritional state. Economic and food assistance programs, such as Meals on Wheels, can greatly aid a geriatric patient in increasing his or her food intake.

The social worker can help the patients arrange transportation for grocery shopping or obtain services from local programs, such as those of the various state departments on aging, which provide the grocery shopping services and food delivery to the home. Also, the social worker can help to devise plans with family members for meal preparation.

CONCLUSION

The prevention and early recognition of malnutrition are essential in the process of rehabilitation because good nutrition is a component of positive outcomes in the rehabilitation setting.

Nutritional support is a team effort. With an understanding and awareness of the factors contributing to malnutrition in the geriatric population, rehabilitation goals are more easily attainable.