Clinical meaning
Refeeding syndrome is a potentially fatal metabolic complication that occurs when nutritional support is reintroduced after a period of prolonged starvation or severe malnutrition. During starvation, the body shifts from carbohydrate to fat metabolism for energy, depleting intracellular stores of phosphate, magnesium, and potassium while maintaining relatively normal serum levels. When carbohydrates are reintroduced, insulin secretion surges, driving glucose and electrolytes (phosphate, potassium, magnesium) into cells for anabolic processes, causing precipitous drops in serum levels. Hypophosphatemia is the hallmark abnormality and can cause respiratory failure (diaphragm weakness), cardiac failure (impaired myocardial contractility), rhabdomyolysis, hemolytic anemia (ATP depletion in red blood cells), and seizures. The nurse must identify at-risk patients (BMI less than 16, prolonged NPO status, chronic alcohol use, anorexia nervosa), initiate feeding slowly at 10-20 kcal/kg/day, supplement thiamine before feeding begins (to prevent Wernicke encephalopathy), monitor electrolytes every 12 hours during the first week, and replace phosphate, potassium, and magnesium aggressively as needed.