Paediatrics: Growth, Development and Childhood Illness
Paediatrics: what is tested
Paediatrics tests growth and development, neonatal care, feeding, dehydration, common infections, congenital heart disease and immunisation. Questions often use age-specific normal values and weight-based calculations.
Core rules
- Development follows a sequence: social smile by 6 weeks, head control by 3 months, sitting without support by 6-8 months, walking by 12-18 months. Red flags include loss of milestones and persistent asymmetry.
- Neonatal jaundice appearing within 24 hours is pathological; check bilirubin, blood group and Coombs status. Kernicterus is prevented by timely phototherapy or exchange transfusion.
- Dehydration is assessed by lethargy, sunken eyes, slow skin pinch and reduced urine output. WHO Plan B uses oral rehydration solution 75 mL/kg over 4 hours for some dehydration; Plan C uses intravenous fluid for severe dehydration.
- Immunisation schedules are age-specific; live vaccines are avoided in significant immunodeficiency and pregnancy.
- Congenital heart disease: cyanotic lesions include tetralogy of Fallot and transposition; acyanotic lesions include ventricular septal defect and patent ductus arteriosus.
Worked example. A 10 kg child has some dehydration after diarrhoea. Reasoning: WHO Plan B gives 75 mL/kg over 4 hours = 750 mL, roughly 190 mL/h, by cup or spoon, with breastfeeding continued. Reassess at 4 hours; if dehydration persists, repeat. Plain water is unsafe because it lacks electrolytes and can worsen hyponatraemia.
Traps that cost marks
- Treating some dehydration with rapid intravenous boluses.
- Correcting hypernatraemia faster than about 10 mmol/L per day.
- Ignoring jaundice in the first 24 hours.
- Using adult urine output targets in children.