Lesson 3

Lesson 3

Pediatric vs. Adult Airway Anatomy

  • Pediatric airway has distinct differences from adult airway.

    • Breathing Pattern: Preferential nose breathing up to 5 months.

    • Tongue Size: Larger relative to oral volume.

    • Neck Length: Shorter than in adults.

    • Epiglottis: U- or omega-shaped, longer, stiffer.

    • Vocal Cords: Anteriorly slanted position.

    • Laryngeal Position: Corresponds with C3-C4 of the cervical spine.

    • Narrowest Regions: Cricoid ring (fixed region) and vocal cords (dynamic region).

    • Subglottic Shape: Funnel-shaped.

    • Bronchus Position: Right mainstem bronchus less vertical (55 degrees off midline).

Key Differences Chart

Feature

Adult

Infant

Implication

Breathing

Mouth or nose

Preferentially nose

Nasal obstruction requires emergency airway management.

Tongue Size

Small

Large

Increased risk of upper airway obstruction.

Neck Length

Longer

Shorter

More difficult visualization during laryngoscopy.

Epiglottis

Leaf or C

U or omega

Stiffer in infants, complicating intubation.

Vocal Cord Pos.

Perpendicular to trachea

Anterior slant

Increased difficulty with blind intubation.

Laryngeal Pos.

C5-C6

C3-C4

Higher epiglottis position allows for feeding and nursing.

Narrowest Point

Cricoid or Vocal Cords

Cricoid ring (fixed) but vocal cords (dynamic)

Intubation Considerations

  • Infants have a higher larynx and a greater risk of difficulty during intubation.

  • Utilize a Miller blade (preferred) for laryngoscopy due to anatomical differences.

  • The cricoid ring is the narrowest fixed region, while the vocal cords represent the dynamic region.

Additional Notes

  • The airway's narrowest region affects endotracheal tube (ETT) selection; trauma at the cricoid can increase airway resistance.

  • Poiseuille's Law: Small changes in airway radius significantly affect airflow resistance (proportional to r4r^4).

  • Children under age 3 have bronchi angled at 55 degrees, making intubation particularly challenging.

  • Conflicting answers regarding the narrowest airway region exist; context is key for exam questions.