Medical Risk Markers in AN — MRCPsych Paper B MCQ

Instant feedback + full explanation. One question, done properly.

ModerateEating DisordersMedical Risk Markers in ANMRCPsych Paper B

A 24-year-old with anorexia nervosa is assessed to determine whether inpatient medical monitoring is required. Which single finding most strongly indicates acute medical instability according to NICE NG69 and current UK eating-disorder emergency guidance?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — Awake heart rate of 38 beats per minute

An awake heart rate of 38 beats per minute is the strongest marker of acute medical instability. NICE NG69 specifically cites bradycardia below 40 beats per minute as an example of a medical risk parameter that may require active inpatient monitoring; current MEED guidance classifies an awake heart rate below 40 as high impending risk to life. A stable low BMI is concerning but must not be used as an isolated admission threshold. A temperature of 36.1°C is not severe hypothermia. Mild anaemia or a modest isolated transaminase elevation warrants assessment but is less immediately concerning than profound bradycardia. Overall risk must still integrate weight-loss rate, blood pressure, temperature, ECG, electrolytes, glucose, hydration, physical function and psychiatric risk.

Reference: National Institute for Health and Care Excellence. Eating disorders: recognition and treatment (NG69), recommendations 1.11.2–1.11.3. Updated 2020. https://www.nice.org.uk/guidance/NG69/chapter/recommendations