There are significant physiologic, anatomic, and equipment differences between
children and adults that must be considered when planning the approach
to the emergent pediatric airway. The presentation of a critically
ill child requiring intubation is relatively uncommon compared to adults.
This chapter presents the physiologic and anatomic characteristics
of the pediatric airway, strategies for effective airway management, and
organization methods for equipment to minimize errors in equipment
sizing and medication dose calculation.1
Due to a higher metabolic rate, oxygen consumption is increased
in children, especially in infants. Infants and children have an
increased relative cardiac output and minute ventilation to match
the increased metabolic demand. However, children are vulnerable
to rapid desaturation when oxygenation or ventilation is reduced.
Children have relatively small volume lungs with small functional
residual capacities. This translates into a reduced oxygen reservoir,
which decreases the effectiveness of preoxygenation and makes optimal
preoxygenation more difficult. Therefore, be prepared to support
oxygenation with bag-mask ventilation, often before an intubation
attempt, while awaiting the onset of induction and paralysis. Attempts
at intubation may need to stop once oxygen saturation drops below
90% to allow for bag-mask ventilation before the next attempt.
Below an oxygen saturation of 90%, desaturation is particularly rapid.2 The
vast majority of children are easily bag ventilated when the proper
technique is used, even when partial obstruction is present. The key
is anticipation and early use of good bag-mask ventilation.
Children have a proportionally larger extracellular fluid compartment than
adults. This results in a quicker onset and shorter duration of
action of drugs, and may require higher doses per kilogram for many
of the drugs used to facilitate rapid-sequence intubation (RSI).
Children can develop gastric distention from air swallowing during
distress as well as insufflation during bag-mask ventilation. Gastric
distention can further compromise functional residual capacity,
tidal volume, and ventilation. Early placement of an orogastric
or nasogastric tube may remedy this. Gastric tubes have also been
recommended to minimize the risk of reflux from an incompetent gastroesophageal
junction, but the incidence of aspiration in children appears to
be quite low, even in emergent intubation.
There are a number of anatomic characteristics of children that
must be appreciated to optimize the success of endotracheal intubation
(Table 29-1). Most of the unique anatomic
characteristics are present in the first few years of life. From
2 to 8 years of age there is a transition to a smaller but similarly
proportioned anatomy compared to adults. Most children do not have
the many acquired anatomic challenges present in older adults, and
the differences in children are predictable. With good technique
and anticipation of these differences, the majority of pediatric
airways are successfully managed.
29-1 Anatomic Considerations in the Pediatric Airway
| Save Table
29-1 Anatomic Considerations in the Pediatric Airway
|Pediatric Anatomy||Potential Implications||Airway Maneuvers|
|Large head and occiput||May push head forward, occluding airway||Shoulder roll may be required to align airway axes|
|Large tongue||May occlude upper airway in obtunded or paralyzed patient||Jaw thrust, oral or nasopharyngeal airway, Miller (straight)
|Superior larynx and anterior cords||May make visualization of cords difficult||Shoulder roll may be required to align airway axes, straight
laryngoscope blade to lift epiglottis|
|Cricoid narrowing||Subglottic space is narrowest portion of the pediatric airway, prone
to inflammation and upper airway obstruction||Monitor cuff insufflation pressures in small children|
|Large adenoids and tonsils||May cause upper airway obstruction; may bleed with nasal
intubation||Avoid blind nasal intubation in young children|
|Small cricoid cartilage||Makes open cricothyrotomy technically difficult||Needle cricothyrotomy preferred in young children|
|Large stomach, low gastroesophageal sphincter tone, relatively small
lungs||Insufflation of stomach with bag-valve mask ventilation or swallowed
air can compromise respiratory status; children are prone to vomiting||Consider early placement of orogastric or nasogastric tube
to deflate stomach when using positive pressure ventilation or in
the obtunded patient|
Alignment of the oral, pharyngeal, and tracheal axes, to allow
visualization of the glottis, is affected by several features most
pronounced in the infant: (1) a relatively large head and occiput,
(2) a disproportionately large tongue and small mandible, and (3)
a larynx that is more superior and anterior than in adults. This
acute angle can be overcome by extending the neck (unless cervical
injury is suspected) and, in some cases, placing a small roll under
the shoulders (Figure 29-1).
Alignment of axes. A. Large
occiput and anterior airway make alignment of airway axes difficult. B. Shoulder
roll aligns tracheal and pharyngeal axes but (C) neck
extension may be needed to align all three airway axes. O = oral,
P = pharyngeal, T = tracheal.
The use of a straight laryngoscope blade is helpful in the presence
of a large tongue and redundant soft tissues. The infant glottic
opening, the epiglottis, and aryepiglottic folds are more prominent,
soft, and mobile than in an adult or older child. This redundant
tissue can obscure the view and make it hard to identify the trachea.
Under tension from a laryngoscope blade, the esophageal inlet can
appear similar to the cords, as it can form a triangle and the edges
appear white when stretched.
The narrow trachea, combined with the redundant, mobile periglottic
tissues, predisposes the young child to airway obstruction.3The
narrowest point of the child’s trachea is at the cricoid
ring, which is also the site of mucosal swelling associated
with croup. Airway
resistance increases disproportionately with any reduction in diameter
and dramatically increases when airflow becomes turbulent rather than
laminar. A ...