Paediatrics: growth, neonatology and emergency numbers
The Paediatrics domain tests whether you can move from a child's presenting complaint to a safe, age-appropriate plan: resuscitate first, then establish aetiology, then definitive and community-level care. Weighting favours neonatology, growth and development surveillance, emergency triage and rational prescribing, with numeric thresholds used as the discriminators between answer options.
Milestones are upper limits, not averages
Developmental windows in examinations are the age by which a skill should be present: social smile by 8 weeks, sits unsupported by 8–9 months, walks independently by 18 months, uses two meaningful words by 24 months, three-word sentences by 36 months. Red flags: loss of acquired skills, persistent primitive reflexes beyond 6 months, asymmetry of tone or hand use, and head circumference crossing centiles upward or downward.
Neonatal numbers
Apgar is scored at 1 and 5 minutes (five components, 0–2 each); resuscitation decisions rest on tone, breathing and heart rate, not the score itself. Jaundice within the first 24 hours is always pathological; physiological unconjugated jaundice appears after 24 hours and peaks on days 3–5. Expect up to 10% weight loss in the first week. Treat glucose below 2.6 mmol/L in a symptomatic or at-risk neonate.
Worked example
An 11 kg child with acute gastroenteritis and "some dehydration". Maintenance by Holliday–Segar: 100 mL/kg for the first 10 kg plus 50 mL/kg for the next 10 kg = 1000 + 50 = 1050 mL/day, about 44 mL/hour. WHO "some dehydration" corresponds to a 5–10% deficit; choose 5%: 0.05 × 11 kg = 550 mL, replaced over 4–6 hours with ORS alongside maintenance. If shock is present (weak pulse, cool peripheries, capillary refill over 3 s), give 20 mL/kg isotonic crystalloid first and reassess.
Traps
Assuming every unwell child is 10% dehydrated doubles the calculated deficit, and inflated fluid rates cause hyponatraemic encephalopathy. Quoting an average milestone age rather than the upper limit of normal labels normal children delayed. Using Apgar to prognosticate, or calling jaundice at 12 hours physiological, are standard distractors. Correct hypernatraemic dehydration slowly - rapid correction risks cerebral oedema.