What are the features of the paediatric airway that differ from adults and what implications do these have?
Features
Implications
- Large head, short neck and a prominent occiput.
- ‘Sniffing the morning air’ position will not help bag mask ventilation or visualisation of the glottis
- Head needs to be in a neutral position.
- Epiglottis is long, stiff and U-shaped. It flops posteriorly
- A straight blade laryngoscope may be advantageous to place underneath and lift up the epiglottis
- Tongue is relatively large
- Inadequate displacement of the tongue may impede visualization of the glottis during laryngoscopy
- Larynx is high, anterior (at the level of C3 - C4) and more acutely angled
- Vocal cords are angled more anteriorly rather than a right angle (90°) to the trachea.
- Typically does not affect laryngoscopic view but can make insertion of the endotracheal tube more challenging or traumatic
- Airway is funnel shaped and narrowest at the level of the cricoid cartilage
- Allows uncuffed tube to form an acceptable seal potentially reducing risk of mucosal damage associated with an inflated cuff
- Trachea is shorter in length than adult's
- Tubes must be carefully inserted to the correct length to sit at least 1cm above the carina
- Tubes should be taped securely to prevent tube dislodgement or endobronchial intubation with head movement
- Trachea is smaller in diameter than adult's
- Epithelium is loosely bound to the underlying tissue
- Trauma to the airway easily results in oedema:
- One millimetre of oedema can narrow a baby’s airway by 60% (resistance ∝ 1/radius)
- A small leak should be present around an uncuffed tube to prevent development of subglottic oedema
- Neonates preferentially breathe through their nose
- May be blocked easily by secretions
- Careful suctioning of the nose is important