Life-threatening refeeding syndrome in a severely malnourished anorexia nervosa patient

Overzealous refeeding in chronically malnourished anorexia nervosa patients may cause life-threatening complications. We describe a 14-year-old girl with anorexia nervosa who had a decrease in body weight from 45 kg to 25.5 kg over an 18-month period. She received 40 kcal·kg^-1·d^-1 carbohydrate-rich nutrition via enteral and parenteral routes. Her serum phosphate concentration dropped from a baseline of 1.39 mmol/L (4.3 mg/dL) to 0.19 mmol/L (0.6 mg/dL) on Day 4 of refeeding. Concurrent with the development of hypophosphatemia, she became drowsy and developed generalized muscle weakness, impaired myocardial contractility, thrombocytopenia, and gastrointestinal bleeding. Fluid overload with pulmonary edema complicated her recovery from these adverse events. After intravenous phosphate supplementation and fluid restriction, the symptoms of refeeding syndrome gradually resolved within 2 weeks. In chronically malnourished anorexia nervosa patients, nutritional support should be instituted gradually to avoid rapid electrolyte shifts and fluid overload. Serum phosphate concentrations, fluid status, and blood cell counts should be closely monitored.