Eating disorders: refeeding and multidisciplinary care — branching viva

Stem

The examiner will test whether you can run a safe refeeding and multidisciplinary-care pathway under pressure. [1] [6]

Branch 1 — Risk stratification

Examiner: A 14-year-old with restricting-type anorexia nervosa is admitted at 71% median BMI after minimal intake for a week. How do you classify her refeeding risk and what do you do before the first feed? [1]

Strong answer: She is high risk — very low %median BMI, negligible intake, rapid recent weight loss, and likely already-low baseline electrolytes. Before the first feed: check baseline phosphate, potassium, magnesium, renal function, glucose and ECG; give thiamine before or with the feed; correct any baseline phosphate, potassium or magnesium deficit; and set a calorie start matched to her high-risk band. [1] [2]

Branch 2 — Mechanism

Examiner: Why does refeeding cause hypophosphataemia? [1]

Strong answer: Reinstating carbohydrate drives an insulin surge, which shifts phosphate, potassium and magnesium intracellularly for ATP synthesis and glycogen storage. Phosphate falls first because the depleted body cannot replenish it fast enough to meet the sudden metabolic demand. Hypophosphataemia then drives respiratory and cardiac failure, weakness and rhabdomyolysis. Fluid retention and increased thiamine demand compound the risk. [1] [2]

Branch 3 — Calorie dosing and evidence

Examiner: How many calories do you start her on, and what is the evidence? [3]

Strong answer: There is no single universal dose; match the start to her risk and the monitoring to the dose. The conservative approach starts low and advances slowly. The STRONG multicentre trial and the 1-year follow-up showed higher-calorie refeeding achieves faster weight gain and shorter stays — but only with intensive phosphate/magnesium/potassium monitoring and proactive replacement. For a patient this high-risk, a cautious start with daily or twice-daily biochemistry and proactive phosphate replacement is defensible; name your guideline (NICE NG69 / AAP / RANZCP / CPS) for the precise dose. [3] [4] [7]

Branch 4 — The falling phosphate

Examiner: On day two her phosphate has fallen sharply. What do you do? [1]

Strong answer: This is evolving refeeding syndrome. Slow or briefly pause the feed, give intravenous phosphate per protocol, and correct potassium and magnesium (magnesium must be adequate before potassium will correct). Confirm thiamine has been given. Monitor cardiac rhythm, daily weight and orthostatic vitals, and escalate to high-dependency if there is haemodynamic instability, respiratory compromise or dangerous arrhythmia. Then resume feeding at a rate the biochemistry tolerates. [1] [2]

Branch 5 — Family-based treatment

Examiner: Her parents are frightened. What is the role of family-based treatment? [5]

Strong answer: FBT (the Maudsley model) is first-line for adolescent anorexia nervosa; a randomised trial showed it superior to adolescent-focused individual therapy. In phase 1 the parents take full, supported charge of her nutrition to restore weight; in phase 2 eating is gradually handed back to her as thinking clears; in phase 3 the focus shifts to normal adolescent development. Phase-1 resistance is expected and is not failure. The clinician coaches the family through it. [5] [6]

Branch 6 — Discharge and step-down

Examiner: When is she safe to discharge, and what is the plan? [6]

Strong answer: Discharge is not weight alone: stable vital signs without orthostasis, acceptable heart rate, normalising biochemistry, normal QTc, sustained oral weight gain, and a family and outpatient team with the capacity to continue care. Step down to a day program or intensive outpatient, continue FBT, arrange outpatient dietetic and mental-health input, and give a named clinician, a weight and biochemistry monitoring schedule, and a relapse and crisis pathway. Discharging without the psychological scaffold is a planned relapse. [6] [5]

Examiner extras

• There is no drug licensed to restore weight in anorexia nervosa; medication is an adjunct, never a substitute for refeeding and FBT. [6]
• Atypical anorexia — significant weight loss from a higher starting weight at a normal or higher BMI — carries the same refeeding risk; do not be reassured by the weight number. [6]
• The malnourished myocardium cannot tolerate fluid overload; be cautious with fluids and never over-resuscitate. [1]