A difficult airway as defined by the American Society of
Anesthesiologists is difficulty with bag-mask ventilation, difficulty
with tracheal intubation, or both.16Other
characteristics of the difficult airway include (1) more than two
attempts at intubation with the same laryngoscopic blade, (2) need
for a change in blade or use of intubation stylet, and (3) need
for an alternative intubation technique or rescue. The incidence
of difficult pediatric airways in the emergency setting is not known,
although the child who cannot be intubated and cannot be ventilated
appears to be less common than the adult.9
Three questions will help guide management decisions:
1. Will I be able to bag-mask ventilate to maintain oxygenation?
2. Are laryngoscopy and intubation likely to be successful?
3. What rescue device, if needed, is most appropriate for this patient?
Difficult pediatric airways fall into three categories: acute
upper airway infections, such as croup and retropharyngeal abscesses; acute
airway obstructions, such as foreign bodies, trauma, or burns; and congenital anatomic
airway abnormalities.4 An approach to each potential
difficulty is beyond the scope of this chapter. However, an understanding
of the principles of management and the rescue devices available
in pediatric airway management will usually lead to an appropriate
Small changes in airway diameter can significantly increase airway
resistance, and when airflow is turbulent, as in a crying, agitated
child, the resistance to flow increases exponentially. This is why
most significant partial pediatric airway obstructions,
potentially requiring intubation, are best managed in the controlled
setting of the operating room with assistance from appropriate consultants,
such as anesthesiology and otolaryngology. Until that time, maintain
the child in a quiet, comforting environment, with minimal stimulation.
The emergency physician must remain prepared for potential deterioration.
Acute upper airway infections, such as croup, are usually gradual
in onset and may respond to medical intervention. Supraglottic infections, such
as epiglottitis or pharyngeal abscesses, may make laryngoscopic
visualization difficult, and rescue devices, such as an LMA, should
be available. If respiratory failure should occur before intervention,
bag-mask ventilation is usually successful because positive pressure
stents open the mobile soft tissues.
Patients with partial obstruction from a foreign body are another
category in which expectant management is advised until care is
transferred to a consultant skilled in fiberoptic or endoscopic
removal. Should complete obstruction occur before intervention,
perform the Heimlich maneuver for children >1 year of age (see Chapter 15, Resuscitation of Children). For
infants, five back blows followed by five chest thrusts are recommended.
Repeat these maneuvers and intersperse with attempts at ventilation
if the child remains conscious. If the child becomes unconscious,
perform direct laryngoscopy. If the foreign body is supraglottic, it
can possibly be removed using Magill forceps during laryngoscopy.
If the obstruction is subglottic, intubation or bag-mask ventilation
may push the foreign body into a mainstem bronchus, allowing temporary
ventilation of the other lung until removal with bronchoscopy. Subglottic
surgical approaches, such as needle cricothyrotomy and supraglottic
rescue devices, are rarely helpful in this setting because the obstruction
usually lies within the trachea, below the level of the cricothyroid
Partial obstruction may require intervention in the ED, due to
rapid progression of the occlusion and the anticipated difficulty
of laryngoscopy and bag-mask ventilation should complete obstruction
occur. Early subspecialty consultation may be needed before any
transfer out of the emergency setting. Burn patients, caustic ingestions,
expanding hematomas, and anaphylactic reactions not responding to
medical therapy fall into this category. Preparation for possible needle
cricothyrotomy should be considered in these cases.
Children with congenital abnormalities associated
with difficult laryngoscopy and bag-mask ventilation, such as Pierre
Robin syndrome, are uncommon but challenging. The ideal management
is aggressive medical treatment of the underlying disease, in hopes
of obviating the need for intubation. Early subspecialty involvement
is also needed in most cases. The most common issue is micrognathia,
pushing the tongue posterior and superior, and obscuring attempts
at laryngoscopy. A subtly recessed mandible may not be appreciated
unless specifically looked for. This can be assessed by drawing
a line from the forehead to the anterior maxilla, and the extension
of this line should touch on the anterior chin in a normal size
mandible.4 Most pediatric patients with micrognathia respond
to bag-mask ventilation or ventilation through an LMA.17
Devices for Children
There are a limited number of rescue devices available for children.
Even fewer rescue devices have any significant literature to support
their use in the ED. This is likely due to the high success rate
associated with good technique in bag-mask ventilation in pediatrics,
the subsequent rare need for a rescue device, and the issue of multiple
sizes needed in any product development.
Supraglottic devices provide oxygenation by creating a seal between
the oropharynx and the glottic opening and ventilating through a
port placed between. The LMA has been described as a successful
rescue device in the pediatric difficult airway.18 The
device recommended in children is the standard LMA, which comes
in sizes small enough to be used in premature newborns, and remains
the only supraglottic device supported by the literature19,20 (Figure 29-8). The insertion technique is
described in Chapter 30, Tracheal Intubation and
Mechanical Ventilation. Placement is rapid and the ability
to successfully ventilate is very high, even in the presence of
distorted anatomy. Approximately 5% to 10% of insertions
are associated with an initial failure to ventilate. Occasionally
this is caused when the tip of the LMA pushes the epiglottis over
the glottic opening, a complication that is more common in children
due to the larger epiglottis.21 If ventilation
is difficult, manifest by poor chest rise or high peak pressures,
the clinician should attempt to reposition the LMA by deflating
the cuff and partially or completely removing and reinserting. The
LMA does not represent a definitive airway, as it does not prevent
aspiration, but it is an excellent means of ventilation and oxygenation
when laryngoscopic attempts have failed. The intubating LMA (see Chapter 30, Tracheal Intubation and Mechanical Ventilation), which is designed to allow intubation through
the device, can only be used in children weighing >30 kg.
Various sizes of pediatric laryngeal mask airways.
There are a number of double-balloon devices in which the tip
is placed into the upper esophagus, and ventilation occurs
between one balloon occluding the proximal esophagus and another
occluding the airway above the glottis. The most studied device
is the Combitube, which can only be used in patients >48 in. tall.
The King LT® (King Systems, Noblesville, IN) (Figure
29-9) is a relatively new device that comes in pediatric sizes
and shows promise in early adult studies; however, experience in
pediatrics is lacking at this time.
Pediatric-sized King LT® (King Systems,
Noblesville, IN) inflated and deflated.
The flexible fiberoptic scope is available in
pediatric sizes and can be useful to evaluate airway difficulty
and facilitate intubation. Experience and practice is needed to
obtain facility with these devices, and the occasion to use them
is rare, which is a challenge to ED application. Furthermore, most
instances require an awake, cooperative patient, which is unlikely in
the distressed young child, even with good topical anesthesia. Therefore,
consultation with experienced subspecialists is often needed, with performance
of the procedure in the operating room.
Fiberoptic stylets allow direct visualization
through an eyepiece mounted on the proximal end of a rigid or malleable
stylet, which incorporates a fiberoptic bundle. The Shikani Optical
Stylet® (Clarus Medical LLC, Minneapolis, MN) and the Bonfils
Retromolar Intubation Scope® (Karl Storz Endoscopy, Culver
City, CA) are two such devices that are available in pediatric sizes.
There are small case series describing the Shikani scope’s
successful use in dysmorphic pediatric cases.22
Video laryngoscopy displays the laryngeal view
on an external monitor from a microvideo camera located at the tip
of the laryngoscope blade. Although the blade and handle have the
familiarity of a traditional laryngoscope, the operator performs
the intubation watching a video screen rather than looking directly
into the oropharynx. A growing literature on these devices suggests
that, in most cases, video laryngoscopy provides equivalent or better
views of the glottic opening than direct laryngoscopy.23 Some
devices, such as the GlideScope® (Verathon, Bothell,
WA), provide blades small enough for the newborn. However, experience
in emergency pediatrics is limited and awaits further study before
recommendations can be made.
Subglottic surgical cricothyrotomy is the final
airway solution when traditional laryngoscopy and rescue airways
have failed or are impossible, and the patient cannot be oxygenated.
The most common indication is the “can’t intubate,
can’t ventilate” scenario, which is extremely
rare in emergency pediatric airway management.5 Open
surgical cricothyrotomy is not an option in children <10 years
old, due to the small cricothyroid membrane. Needle cricothyrotomy
is, therefore, recommended in children <10 years old. Actual
experience in the emergency setting is limited, but success has
been described in case reports, animal studies,
and the operating room. The procedure involves placing a large-gauge,
over-the-needle catheter (usually 14 gauge) through the cricothyroid
membrane or upper trachea. Nonkinking catheters are available for this
purpose and preferred, but a standard 14-gauge over-the-needle catheter
can be used. Jet ventilation, through high-pressure oxygen
tubing attached directly to 50-psi wall-mounted oxygen and the catheter, should
only be used for children >5 years old due to the potential for barotrauma. If
jet ventilation is used in children, the pressure should be reduced
using a pressure gauge or air leak available in commercial transtracheal
jet ventilation devices designed for this purpose. In children <5 years
old, ventilate through the catheter with a bag ventilator. This
method can be used in older children also. Use the adapter from
a 3.0 mm ID endotracheal tube to connect a standard catheter to
the bag (Figure 29-10).
A. Equipment required for a needle cricothyrotomy:
a 14-gauge over-the-needle catheter (ideally nonkinking), a 3.0
internal diameter endotracheal tube adapter, and a 10-cc syringe. B. Placement
of catheter into trachea. C. Ventilation through the
catheter using a 3.0 endotracheal tube adapter.