Pediatrics
Pediatrics tests the physiological differences from adults: weight-based dosing, dehydration, distress in small airways, and immunization timing.
Core rules
- Dehydration: clinical estimate plus weight loss. Mild <5%, moderate 5–10%, severe >10%. Deficit (mL) = % dehydration × weight (kg) × 10.
- Maintenance by the 4-2-1 rule: 4 mL/kg/h for the first 10 kg, 2 for the next 10, 1 thereafter.
- Oral rehydration salts are first-line for mild–moderate dehydration; IV isotonic saline for shock or failed oral trial.
- Croup (barking cough, stridor, no drooling) responds to dexamethasone, with nebulized adrenaline for moderate–severe disease. Suspected epiglottitis: do not examine the throat, keep the child calm, call anesthesia.
- Neonatal jaundice: treat by hour-specific bilirubin nomogram; screen for hemolysis and sepsis.
Worked example
A 10 kg child with 6% dehydration, alert, mild sunken eyes, reduced urine output. Deficit = 0.06 × 10 × 1000 = 600 mL. Maintenance = 4 × 10 = 40 mL/h. Plan: replace 600 mL over 6 hours (100 mL/h) plus maintenance, using oral rehydration salts if tolerated, reassessing after each 100 mL and checking glucose.
Traps
- Using adult drug doses; always dose by weight and check maximums.
- Assuming a quiet child is well - assess work of breathing, feeding, and urine output.
- Missing hypoglycemia and hypothermia in neonates.
- Meeting stridor and drooling with a tongue depressor instead of airway readiness.