SAQ 323 – Psychiatry – eating disorder definitions and admission criteria

Psychiatry – eating disorder definitions and admission criteria.

a. Anorexia nervosa

• Restriction of calorie intake resulting in pathologically low body weight.

b. Bulimia nervosa

• Repetitive, compulsive episodes of binge eating.
• Compensatory behaviours to prevent weight gain, such as purging, laxatives, or diuretics.

c. Complications

• Cardiovascular: syncope or dysrhythmias.
• Metabolic: hypoglycaemia or low potassium, magnesium, phosphate, or sodium.
• Haematology: anaemia or neutropenia.
• Gastrointestinal: liver failure or constipation.
• Skeletal: osteoporosis.
• Psychiatric: depression.
• Refeeding syndrome with electrolyte and glucose disturbance.

d. Admission criteria

• BMI <12.
• Hypothermia <35.5 C.
• Cardiovascular instability: heart rate <50, systolic BP <80 mmHg, or postural BP drop >20 mmHg.
• Electrolyte/metabolic abnormality: K <3 mmol/L, Na <125 mmol/L, or BSL <3 mmol/L.
• Neutrophils <0.7.
• Renal impairment with eGFR <60 mL/min.
• Failure to respond to outpatient management.