Peds airway — what's different

Pediatric airway anatomy + drug differences

Mnemonic device

Anterior · Cephalad · Floppy

Mapping

Anatomy

Larynx anterior + cephalad (C3-4 vs C5-6 adult); large floppy epiglottis (use Miller blade <5 yr); large tongue; cricoid is narrowest point in <8 yr (now debated; some studies show glottic level)

Physiology

↑ O2 consumption 2x adult, ↓ FRC relative — desaturation FAST; preoxygenate well

Drugs

Larger Vd (more total body water) → induction doses higher per kg (propofol 3 mg/kg vs 2 in adult); volatile MAC higher in infants 6-12 mo than adults

ETT

Cuffed ETT now standard; size = (age/4)+3.5 (cuffed) or (age/4)+4 (uncuffed); depth = (age/2)+12 cm at lip

Reflexes

Vagal predominance — bradycardia is the response to stress (hypoxia, laryngoscopy, suction); atropine 0.02 mg/kg works fast

Clinical note: URI within 2-4 weeks → reactive airway risk: bronchospasm, laryngospasm, ↑ desaturation. Defer elective if active URI; consider regional or topical alternatives.