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- Protein-energy malnutrition (PEM) is present when sufficient energy and/or protein is not available to meet metabolic demands, leading to impairment in normal physiologic processes. It is highly associated with systemic inflammation.
- Mostly seen in children in resource-limited countries
- Malnutrition in children is a major underlying factor in ~5 million preventable deaths annually, with two distinct phenotypes.
- Marasmus (wasting syndrome): a wasting condition due to deficiency of calories and protein
- Kwashiorkor: generalized edema and ascites, associated with low protein relative to caloric intake
- System(s) affected: immunologic, gastrointestinal, endocrine/metabolic, hematologic, musculoskeletal, integumentary, neurologic
- Most commonly <5 years of age
- Prevalent sex: males = females
- Globally, malnutrition increases morbidity and mortality from other common childhood diseases.
- Older patients
- Intake reduction is one of the main causes of chronic malnutrition in the elderly.
- Highest risk group age >75 years, affecting 5–10% of nursing home residents and up to 50% of older patients on hospital discharge
- Increased mortality and morbidity, including pressure ulcers, infection, and cognitive status changes
- Common causes:
- Geriatric anorexia
- Alterations in taste and smell
- Hormone changes regulating gastric/intestinal motility
- Mood alterations (dementia, depression)
- Malnutrition may be common, but it is difficult to recognize in hospital populations.
- Worldwide, >70 million children suffer from moderate and severe acute malnutrition.
- Prevalence in older patients is between 29% and 61%.
Etiology and Pathophysiology
- Inadequate dietary intake
- Increased metabolic demands
- Increased nutrient losses
- Conditions that predispose the patient to cachexia also increase the risk of PEM.
- Starvation-related malnutrition
- Prolonged and severe reduction of intake
- Anorexia nervosa
- Chronic inflammatory states (rheumatoid arthritis, chronic cardiac or lung disease, and cancer)
- Metabolic disorders (diabetes, hyperthyroidism)
- Malabsorptive and maldigestive states (celiac disease and pancreatic insufficiency)
- Protein-losing enteropathy, liver cirrhosis, chronic kidney disease, nephrotic syndrome, enteric fistulas
- Marked inflammatory conditions: acute disease, fever, infection, trauma, burns, closed head injury
- Other states in which caloric requirements are increased: pregnancy and lactation, childhood growth and development
- Functional, financial, and social factors may limit access to an adequate diet, particularly in geriatric and pediatric populations.
- Elders with delirium, dementia, or depression or long periods spent NPO or with prolonged hospitalization are at high risk for malnutrition.
- Extreme high- or low-BMI individuals are also at increased risk.
- Malnutrition can occur in healthy weight or overweight individuals. BMI can be a tool in the identification of chronic malnutrition in patients but should not be used as a sole method of screening or diagnosis.
- Cirrhotic patients: PEM is one of the most common complications in liver cirrhosis and is associated with an increased risk of variceal bleeding, ascites, hepatic encephalopathy, and hepatorenal syndrome.
- Observation and recording of patients’ nutritional intake and BMI
- In children, routine record of anthropomorphic measurements and developmental milestones
- Early recognition of increased nutritional requirements during stress, infection, and other medical illness
- Frequent interactions among physician, nurse, and dietitian to assess nutritional needs
- Emphasis on food security and nutritional education
Commonly Associated Conditions
- Infection: weakened immune system, predisposing to bacterial, viral, and parasitic infections
- Electrolyte disturbances: loss of cellular integrity, diminished transmembrane pump activity, renal dysfunction
- Hypoglycemia: decreased glycogen stores, increased glucose use (as in infection or trauma)
- Micronutrient deficiencies: vitamins, including B complex, folic acid, iron, magnesium (1)
- Wounds: pressure ulcers in older patients (increased incidence if reduced mobility)