AIDS wasting syndrome

Pathophysiology

The mechanisms by which HIV causes malnutrition include decreased nutritional intake, metabolic abnormalities, and the combination of diarrhea and malabsorption. Decreased oral intake may be related to loss of appetite, oral or esophageal ulcers (esp. from Candida or herpes simplex virus), difficulty chewing, fatigue, changes in mental status, or inadequate finances. Metabolic abnormalities include elevated serum cortisol, decreased anabolism, micronutrient deficiencies (vitamin B₁₂, pyridoxine, vitamin A, zinc, and selenium), and decreased antioxidants. Malabsorption and diarrhea affect 60% to 100% of patients with AIDS. Primary gastrointestinal pathogens that contribute to malnutrition include Cryptosporidia, Microsporidia, and Mycobacterium avium intracellulare. Concerns about diarrhea and fecal incontinence may underlie a patient's decreased oral intake.

Patient care

Assessment and education of patients must begin as soon as they are diagnosed as having HIV infection. Obtaining a careful history of the patient's normal nutritional intake and activity level provides the baseline for nutritional instruction. Patients are encouraged to maintain the recommended daily allowance (RDA) for all foods by following MyPyramid; protein intake of 1 to 2 g/kg of ideal body weight and vitamin and mineral intake three to four times the RDA are also encouraged. Small frequent feedings, good oral hygiene, limited fluids with meals, and the use of preferred foods are helpful strategies in countering anorexia. A written schedule may help the patient adhere to the recommended plan for intake. Any increase in exercise or activity must be accompanied by an increase in food intake.