The pediatric respiratory system differs significantly from adults, making children prone to rapid decompensation.

• Airway Size: An infant's trachea is approximately 4 mm wide (vs. 20 mm in adults). Even 1 mm of edema can reduce the airway diameter by 50%, significantly increasing resistance and work of breathing.

• Physiology: Children have higher metabolic rates and oxygen consumption (6–8 L/min vs. 3–4 L/min in adults), causing hypoxemia to develop more rapidly during distress.

• Assessment Priorities: The first sign of respiratory illness is often tachypnea. Other critical signs include retractions (suprasternal, intercostal), nasal flaring, grunting, and head bobbing. Quiet chests in asthmatics can indicate severe obstruction (lack of air  ...