Immediate Admission and Refeeding Management for Severe Anorexia Nervosa (BMI ≈ 10)

Severity and Cardiac Risk

A BMI of 10 reflects life‑threatening malnutrition (< 70 % of ideal body weight) and confers an extremely high risk of sudden cardiac death and refeeding‑related complications. American College of Cardiology. 1, 2
Prolonged starvation leads to cardiac muscle atrophy and pericardial effusions. American College of Cardiology. 2
Low BMI is a strong independent predictor of QTc interval prolongation, predisposing to fatal arrhythmias. American College of Cardiology. 2
Sinus bradycardia and other ECG abnormalities are common and are worsened by electrolyte disturbances. American College of Cardiology. 1, 2
Up to one‑third of deaths in anorexia nervosa are cardiac‑related; overall mortality is ≈ 6 %. American College of Cardiology; European Society of Cardiology. 1, 2, 3
Sudden cardiac death can occur at any time in severely malnourished patients; each day of admission delay increases fatal risk. American College of Cardiology. 1, 2

Cardiac complications of refeeding syndrome most often arise within the first week of nutritional support in patients with severe malnutrition (< 70 % IBW). American College of Cardiology. 2
Refeeding triggers rapid intracellular shifts of potassium, magnesium, calcium, and phosphate, producing precipitous falls in serum levels. Gastroenterology Society. 4
Sodium‑driven water redistribution can cause acute fluid overload. Gastroenterology Society. 4
The syndrome may progress to cardiac and respiratory failure, altered mental status, coma, and death. Gastroenterology Society. 4
Hypophosphatemia is the classic biochemical hallmark; concurrent thiamine deficiency can precipitate additional complications. Clinical Nutrition Society. 5, 6

Initial caloric intake should be ≈ 10 kcal/kg/day for very high‑risk patients; some experts consider even 20 kcal/kg/day excessive. Gastroenterology Society. 4
Thiamine 200–300 mg daily must be given before any feeding begins and continued for at least three days. Clinical Nutrition Society. 5, 6
Potassium supplementation of 2–4 mmol/kg/day is recommended during refeeding. Clinical Nutrition Society. 5
Phosphate supplementation of 0.3–0.6 mmol/kg/day should be provided. Clinical Nutrition Society. 5, 6
Magnesium 0.2 mmol/kg/day intravenously or 0.4 mmol/kg/day orally is advised. Clinical Nutrition Society. 5, 6
A balanced micronutrient mixture should accompany the feeding regimen. Clinical Nutrition Society. 5

Continuous assessment of volume status, fluid balance, heart rate, and cardiac rhythm is essential. Clinical Nutrition Society. 5
Daily laboratory checks of potassium, phosphate, magnesium, and calcium are required. Gastroenterology Society; Clinical Nutrition Society. 4, 5
Ongoing clinical evaluation for signs of cardiac or neurological deterioration must be performed. Clinical Nutrition Society. 5

Admission should occur without delay; postponing care increases the risk of sudden cardiac death in an unmonitored environment where immediate resuscitation may be unavailable. American College of Cardiology. 1, 2
Once admitted, the first week is critical because refeeding syndrome can cause fatal cardiac events. American College of Cardiology. 2
Immediate admission is the only medically defensible strategy because it addresses both pre‑admission cardiac instability and post‑admission refeeding risks. Gastroenterology Society; American College of Cardiology. 4, 1, 2
Most cardiac abnormalities in anorexia nervosa are reversible with appropriate refeeding, provided the patient survives to receive treatment. American College of Cardiology. 2