Eating disorders: recognition and medical instability — formative SAQs

SAQ 1 — Fainting 15-year-old runner (10 marks)

A 15-year-old cross-country runner is brought to the emergency department after fainting at school. Over three months she has cut out all carbohydrates, runs before dawn, and her periods have stopped. Her weight sits in the "healthy" band. Her resting heart rate is 38 beats per minute and rises markedly when she stands up. She believes she is "a bit overweight." ^{[3] [4]}

Questions

1. Outline your immediate recognition, screening and instability assessment. (4 marks) ^[3]
2. List the physiological red flags that would mandate admission and state which are present here. (4 marks) ^[4]
3. Give your disposition and immediate management priorities, and the key pitfall in this presentation. (2 marks) ^[5]

Model answer

Recognition, screening and instability (4). Recognise an eating disorder with atypical-anorexia features: restriction, driven exercise, amenorrhoea, syncope and body-image disturbance despite a non-low weight. See her alone, apply SCOFF (two or more positive supports the diagnosis) and a HEEADSSS psychosocial frame. Quantify instability: weigh in a gown and plot percentage of median body mass index; measure lying and standing heart rate and blood pressure (a standing test), temperature, and a 12-lead ECG for QTc and rhythm; check bedside glucose and electrolytes. ^{[3] [4]}

Red flags and those present (4). Red flags (Junior MARSIPAN framing): severe resting bradycardia (under about 40 beats per minute), hypotension (under about 80/50), a marked postural heart-rate rise or systolic blood-pressure drop, a prolonged QTc, hypothermia, syncope, hypoglycaemia and rapid weight loss. Present here: severe bradycardia (38), a marked postural heart-rate rise, and syncope — each alone would mandate admission. ^{[4] [6]}

Disposition, priorities and pitfall (2). Same-day medical admission with cardiac monitoring; correct potassium, magnesium and phosphate and treat hypoglycaemia; begin cautious refeeding because feeding triggers refeeding syndrome. The key pitfall is reassurance on the basis of a "healthy" weight — atypical anorexia carries the same danger as anorexia nervosa. ^{[5] [3]}