A child's airway is not just a smaller adult airway. Its size, shape and position change with age, and these differences make children more likely to block their airway and to tire quickly.
Head and tongue
Infants have a large back of the head (occiput), which bends the neck forward when they lie flat. The tongue is large for the mouth and can easily block the airway.
Position and shape
The larynx sits higher and more forward, at about C3 to C4 instead of C5 to C6 in adults. The epiglottis is longer, floppier and U-shaped, which makes it harder to lift with a laryngoscope.
Small diameter
The airway is narrow, so even a little swelling greatly reduces airflow; resistance rises sharply as the airway gets smaller. In young children the narrowest point is traditionally described at the cricoid ring, below the vocal cords.
Breathing mechanics
Young infants breathe mostly through the nose, so a blocked nose can cause distress. Soft ribs, reliance on the diaphragm and a higher oxygen use per kilogram mean children drop their saturation quickly and show retractions when breathing is hard.
| Feature | Child | Adult |
|---|---|---|
| Back of the head | Large, bends the neck forward | Neck neutral when lying flat |
| Tongue | Large for the mouth | In proportion |
| Larynx level | About C3 to C4 | About C5 to C6 |
| Epiglottis | Long, floppy, U-shaped | Shorter and firmer |
| Normal breathing rate | Infant 30 to 60 per minute | 12 to 20 per minute |
At the bedside
Place a small towel under an infant's shoulders to bring the airway into a neutral position, and suction the nose if it is blocked. Use the pediatric assessment triangle, and treat retractions, grunting or nasal flaring as signs of serious distress.
Related guides
Written by Making Synapses. Topic reference: OpenStax, Anatomy and Physiology 2e (no text adapted).