A 22-year-old female college student presents with a 2-year history of severe food restriction, excessive exercise (3–4 hours daily), and intense fear of weight gain despite weighing 38 kg at a height of 162 cm (BMI 14.5 kg/m²). She denies binge eating or purging. On examination, she appears cachectic with fine body hair, cold extremities, and a heart rate of 48 bpm. Laboratory findings show serum potassium 3.2 mEq/L, magnesium 1.6 mg/dL, and albumin 2.8 g/dL. What is the most appropriate initial management priority?

Explanation

## Clinical Assessment **Key Point:** This patient meets criteria for Anorexia Nervosa (AN), Restrictive Type, with severe medical complications requiring inpatient care. ### Severity Indicators Present - BMI 14.5 kg/m² (severe malnutrition; normal BMI 18.5–24.9) - Bradycardia (48 bpm) — sign of cardiac compromise - Hypokalemia (3.2 mEq/L; normal 3.5–5.0) and hypomagnesemia (1.6 mg/dL; normal 1.7–2.2) - Hypoalbuminemia (2.8 g/dL; normal 3.5–5.5) — protein malnutrition - Lanugo (fine body hair) — metabolic adaptation to starvation ### Why Inpatient Hospitalization is Indicated **High-Yield:** Electrolyte derangements (especially potassium and magnesium) in the setting of severe malnutrition and bradycardia carry high risk for sudden cardiac death, particularly during refeeding (refeeding syndrome). Cardiac monitoring is essential. **Clinical Pearl:** Refeeding syndrome occurs when nutrition is reintroduced too rapidly in severely malnourished patients. Phosphate, potassium, and magnesium shift intracellularly, causing life-threatening arrhythmias. Slow, monitored refeeding in hospital is the gold standard. ### Management Hierarchy for Severe AN ```mermaid flowchart TD A[Anorexia Nervosa Diagnosis]:::outcome --> B{Medical Stability?}:::decision B -->|Unstable: BMI < 16, electrolyte abnormalities, bradycardia| C[Inpatient Hospitalization]:::action B -->|Stable: BMI > 16, normal labs, HR > 50| D[Outpatient Management]:::action C --> E[Cardiac Monitoring]:::action C --> F[Electrolyte Repletion]:::action C --> G[Slow Refeeding Protocol]:::action D --> H[Psychotherapy + Nutritional Counselling]:::action E --> I[Prevent Refeeding Syndrome]:::outcome ``` **Mnemonic: SCOFF** (screening tool for eating disorders): - **S**ick from eating small amounts - **C**ontrol: preoccupation with food control - **O**ver 6 kg weight loss in 3 months - **F**at: fear of being fat - **F**ood: food dominates life (≥2 positive responses warrant further assessment) [cite:DSM-5 Diagnostic Criteria for Anorexia Nervosa; Harrison 21e Ch 385]