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108
Airway management is an important aspect of pediatric
emergency care. Prompt, effective airway access can mean the
difference between a good outcome and disability or death. Op-
timal management requires an understanding of the differ-
ences between children and adults with respect to airway
anatomy and physiology and response to medications to facili-
tate airway access. In most cases, the emergency physician is
called to secure a childs airway with little forewarning. This
review details a logical and practical approach to the uncom-
plicated pediatric airway. Emphasis is also placed on recogni-
tion of the difficult airway and methods to render the difficulty
less daunting. Good judgment and the appropriate skills are
the prerequisites for success.
TARGET AUDIENCE
This CME activity is intended for physicians, nurses, nurse prac-titioners, physician assistants, and paramedics who care for chil-
dren in respiratory distress or cardiopulmonary arrest. Specialists
including pediatricians, emergency physicians, pediatric emer-
gency physicians, anesthesiologists, and trauma surgeons will find
this information particularly useful.
LEARNING OBJECTIVES
After completion of this article, the reader will
1. Be able to recognize the difficult airway and make the prepara-
tions necessary for the clinical scenario.
2. Be able to discuss the role of neuromuscular blocking agents
and induction drugs in airway management.
3. Be able to describe the management of the uncomplicated air-
way using manual ventilation with a bag and mask or direct
laryngoscopy.
4. Be familiar with alternative techniques for the difficult airway,
including blind nasotracheal intubation, lighted stylet, laryngeal
mask airway, flexible fiberoptic laryngoscope, retrograde intu-bation, and needle cricothyrotomy.
INTRODUCTION
Good airway management in the pediatric emergency depart-
ment (ED) can mean the difference between an acceptable out-
come and permanent disability or death. Airway management in
the critically ill child is a challenge for several reasons: it occurs
rarely, is often unanticipated, and must be achieved with little time
to plan in children with limited respiratory reserve. Moreover, the
emergency physician must sometimes provide airway manage-
ment without the benefit of fully knowing the extent of the pa-
tients injuries or medical conditions. Antecedent conditions (eg,
full stomach, shock, elevated intracranial pressure, and cardiovas-cular disease) complicate management and may not be immedi-
ately evident. As a consequence, the emergency physician must
choose strategies that are likely to succeed with few potential
complications.
Patients in the ED who require urgent or emergent airway man-
agement usually present with little advance warning; hence, there is
limited opportunity to mobilize specialized personnel and equip-
ment before the patients arrival. This is different from the operat-
ing room where an anesthesiologist faced with a difficult airway can
usually get help from several anesthesiologists and has an array of
airway adjuncts. Elective surgical cases complicated by airway dif-
ficulty can be managed by canceling surgery until well-planned al-
ternative techniques are available. The emergency physician usually
cannot return at another time with a better strategy.Optimal outcomes with pediatric airway management require a
thorough understanding of the physiologic, pharmacodynamic, and
anatomic differences between children and adults. Additionally,
good preparation, difficult airway recognition, and familiarity with
back-up plans for airway management are essential. This review is
intended for emergency physicians and, thus, will focus on devices
and techniques easily obtained and used in the ED.
PREPARATION
The first step toward success in securing a childs airway is appre-
ciation of the unique physiologic and anatomic differences between
0749-5161/02/1802-0108 Vol. 18, No. 2
PEDIATRIC EMERGENCY CARE Printed in U.S.A.
Copyright 2002 by Lippincott Williams & Wilkins, Inc.
EDITORS NOTE: This article is the second of six that will be published in 2002 for which a total of up to 6 Category
1 CME credits can be earned. Instructions for how credits can be earned appear on the last page of the Table of Contents.
CME REVIEW ARTICLE
*Pediatric Anesthesiologist and Intensivist, Departments of PediatricAnesthesia and Critical Care, Nemours Childrens Clinic, and Professor andChief, Division of Critical Care Medicine, University of Florida, Jacksonville,Florida.
Address for reprints: Niranjan Kissoon, MBBS, Professor and Chief, Di-vision of Critical Care Medicine, University of Florida Health SciencesCenter, 820 Prudential Drive, Suite 203, Howard Building, Jacksonville,FL 32207; e-mail: niranjan.kissoon@jax.ufl.edu
Key Words: Airway management, intubation, emergency resuscitation,respiratory failure
Securing the childs airway in the emergencydepartmentKEVIN J. SULLIVAN, MD,* NIRANJAN KISSOON, MBBS
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adults and children. Infants and children are likely to experience
arterial oxygen desaturation more rapidly than adults for several rea-
sons (Table 1). With pulmonary disease or short periods of apnea, the
rate of desaturation can be considerably shorter (1) because of in-
creased rate of oxygen consumption and the inability of the child to
preserve functional residual capacity (FRC).
Oxygen Consumption and Metabolic Rate. On average,
adults consume a total of 2 to 3 cc/kg/min of oxygen under basal con-ditions. As a result of factors related to growth and higher basal meta-
bolic rate, infants and children may consume 2 to 3 times as much
oxygen per kilogram of body weight under basal conditions (2).
Therefore, even if physiologic oxygen stores were identical, the
child would likely experience desaturation during even short peri-
ods of apnea.
Diminished Pulmonary Reserve. The FRC, a reservoir for gas
exchange, represents a similar percentage of total lung capacity in
awake children as in adults but not in anesthetized or paralyzed chil-
dren (3, 4). The diminished outward chest recoil of the infant causes
the FRC to plummet when some of the compensatory, active mech-
anisms for FRC preservation are abolished by the administration of
neuromuscular blocking and sedative medications. The net result of
the infants higher oxygen consumption and diminished oxygen re-serves is a tendency toward more rapid arterial oxygen desaturation
that is accelerated with coexistent lung disease.
Anatomic Differences. The anatomic differences pertinent to
airway management are outlined in Table 2. The infants prominent
occiput pushes the head into a flexed position, which causes airway
obstruction when the child is placed on the back. This can be over-
come by placing a towel roll under the shoulders. Care must be
taken to avoid excessive neck extension, because this, too, can re-
sult in airway obstruction.
The relatively large tongue of the infant, along with the rela-
tively small nares, causes increased resistance to airflow from a
facemask. Care must be taken to prevent the fingers holding the
mask hand from compressing the soft tissue structures of the floor
of the mouth. This can be avoided by making sure that all of thedigits of the hand are on bones of the chin, mandible, and mask it-
self. Additionally, early use of oropharyngeal or nasopharyngeal
airways (when not contraindicated) is encouraged.
Endotracheal intubation is complicated by the presence of smaller
airway structures with the larynx located higher in the neck (C4 vs
C6), which gives it an anterior and cephalad appearance. The epiglot-
tis is longer and omega shaped, and it is positioned in a shorter neck
close to prominent adenoid and tonsillar tissue. The trachea is short
and has a greater potential for inadvertent endobronchial intubation.
Finally, the cricoid cartilage ring is the narrowest part of the airway
as opposed to the glottis in adults. Attention to these anatomic dif-
ferences can help to prevent unnecessary postextubation stridor and
subglottic stenosis.
Because pediatric patients are prone to rapid arterial oxygen de-
saturation and may be difficult to mask ventilate or intubate, it is
essential to have all airway equipment readily available and in
working order. It is also prudent to have a back-up plan and equip-
ment available for situations in which standard mask ventilation
and intubation are difficult or impossible. This is particularly rele-
vant to the ED, where the clinician may not have the luxury of a
thorough airway assessment.
Recognition of the Difficult Airway. It is critical to recognize
the difficult airway before using induction agents and neuromuscu-
lar blockade, because failure to do so can result in a life-threatening
situation in which ventilation and intubation are impossible. Choos-
ing alternative awake, asleep, or spontaneously breathing tech-
niques for airway management in children with difficult airways can
be the difference between a smooth intubation and a fatal airway
flail.
In the absence of specific anatomic markers of airway abnor-mality, facial and upper airway trauma, or inflammation, it is ex-
ceedingly unlikely to be surprised by a difficult airway. A history
of difficult airway in the patient can be identified from Medic-Alert
bracelets or from the caretakers of children with conditions known
to predispose to airway difficulty. A prior history of airway treach-
ery is a red flag to heed, particularly if the difficulties occurred in
the hands of clinicians who are experienced in the airway manage-
ment of children. Physical findings that predict airway difficulty
are summarized in Table 3 and are discussed below.
Oropharyngeal Examination. The oropharyngeal examination
is the first step in assessing the airway. The patients oral cavity is
examined with his or her mouth open and the tongue maximally
protruded. The degree of mouth opening and the size of the tongue
relative to the oral cavity are assessed. Mallampati et al. (5) classi-fied airways on the basis of the degree of visualization of the fau-
cial pillars, soft palate, and uvula. The ability to see a large part of
these structures predicts a high probability of adequate laryngeal
visualization in adults. Whether the Mallampati et al. score can suc-
cessfully predict the degree of difficulty with endotracheal intuba-
tion in small children is not known.
Macroglossia, an absolute or relative enlargement of the tongue
in relation to the oral cavity, is a prominent feature of Down and
Beckwith-Wiedemann syndromes and is associated with airway
difficulty. Infiltration or crowding of the tongue and airway struc-
tures is commonly seen in mucopolysaccharidosis, morbid obesity,
cystic hygroma, edema, and cellulitis. The presence of a high,
arched palate is also associated with airway difficulty.
Vol. 18, No. 2 SECURING THE CHILDS AIRWAY IN THE ED 109
TABLE 1Respiratory physiologic differences between children and adults
Increased respiratory rateIncreased chest wall complianceDecreased lung elastic recoil (lower lung compliance)Diminished functional residual capacityIncreased rate of oxygen consumption
TABLE 2Anatomic differences between pediatric and adult airways
More prominent occiputTongue occupies relatively larger proportion of oral cavitySmall nasal passagesHypertrophied lymphoid tissueShort tracheaLong epiglottis
Larynx appears more anterior and cephalad
TABLE 3Findings that predict the presence of a difficult airway
Limited mouth openingCervical spine immobility (immobilization, trauma, degenerative
processes)Small mouthProminent central incisorsShort mandibleShort neckLarge tongue (relative or absolute)Obese patientsLaryngeal edema (infection, inhalation thermal injury)Mandibular, midface, and facial trauma
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Neck Extension. Neck extension is often necessary during
laryngoscopy to create a direct, straight line of vision from the
mouth to the glottic structures. Successful laryngoscopy can be per-
formed without neck extension, as is often necessary in the setting
of known or suspected cervical spine trauma. However, inability to
extend the neck as a result of trauma or congenital cervical spine
abnormalities (eg, trisomy 21, Goldenhar and Klippel-Feil syn-
dromes), juvenile rheumatoid arthritis, or prior cervical spine fixa-tion is a predictor of difficult intubation and ventilation.
Mandible Length. The mandible length refers to the distance
from the thyroid cartilage to the chin and is normally greater than
1.5 cm in infants (6). Patients who have a short mandible present
greater difficulty in lining up the pharyngeal, laryngotracheal, and
oral axes. These patients are said to have an anterior larynx because
the line of vision during laryngoscopy falls posterior to the airway
structures. Children with short mandibles must also compress more
tongue and oral structures into a small space, which often results in
difficulty with mask ventilation. Micrognathia is a salient feature of
Treacher-Collins and Pierre Robin syndromes.
The degree of airway abnormality, prior history of airway mis-
adventure(s), and the ability of the patient to physiologically toler-
ate the proposed airway procedure are factors that must be consid-ered when deciding on an airway strategy. It is imperative to
carefully consider these factors before attempting to control the air-
way in the spontaneously breathing child. When presented with the
profoundly compromised or apneic child, these criteria are useful
to predict airway compromise and allow for ancillary personnel
and techniques while the clinician initiates simultaneous airway
support.
Monitoring. Monitoring of the electrocardiogram, pulse ox-
imeter, and noninvasive blood pressure is important for several rea-
sons. This allows the clinician to assess the patients response to in-
duction drugs, ventilation, brief periods of apnea, and the detection
of unsuspected problems such as ongoing internal bleeding, peri-
cardial tamponade, tension pneumothorax, and increased intracra-
nial pressure.It is also essential to monitor of end-tidal carbon dioxide
(ETCO2). Detection of ETCO2 after endotracheal intubation is a
very sensitive and specific method to confirm endotracheal place-
ment of the tube. Despite proper tube placement, there may be lit-
tle or no carbon dioxide detected with the markedly diminished
pulmonary blood flow seen during cardiac arrest and profound hy-
povolemia (7). It is also possible to have a few weak signals of car-
bon dioxide if the endotracheal tube is in the esophagus and an
ETCO2 signal if the endotracheal tube is in the pharynx, above the
vocal cords (8, 9). Despite these pitfalls, ETCO2 detection and vi-
sualization of the endotracheal tube as it passes through the glottis
is the most reliable way to prevent inadvertent esophageal intuba-
tion. Additionally, the trend in ETCO2 is a guide to assessing the
response of the patient to cardiopulmonary resuscitation, fluid ther-
apy, inotropic agents, and the adequacy of ventilation (10, 11). It
can also rapidly detect inadvertent extubation during transport and
endotracheal tube repositioning.
Equipment for Airway Management. The equipment avail-
able for emergency airway management is listed in Table 4. Self-
inflating resuscitation bags are the simplest and most commonly
used items in the ED. They require a high liter flow of oxygen and
an inspiratory manifold and reservoir to maximize inspired oxygen
concentration (1214). Self-inflating resuscitation bags offer the ad-
vantage of allowing ventilation of the patient with room air if the
oxygen source becomes exhausted or disconnected. However, spon-
taneous ventilation through the inspiratory valve may be difficult.
Rebreathing of carbon dioxide is not possible, irrespective of the
rate of fresh gas flow into the apparatus as a result of the presence of
unidirectional exhalation valves. Positive end-expiratory pressure
(PEEP) can be administered through manipulation of built-in popoff
valves or through the addition of extraneous PEEP valves.
The use of Mapleson D ventilation bags allows for easy sponta-
neous ventilation and allows the clinician to easily adjust levels of
PEEP without the addition of extraneous valves. Unlike self-filling
bags, Mapleson circuits require a continuous oxygen supply to
function, because they cannot entrain room air. It is also necessaryto ensure a fresh gas flow at least 2 to 3 times the minute ventila-
tion for spontaneous ventilation and 1 to 2 times the minute venti-
lation for controlled ventilation to prevent rebreathing of carbon
dioxide (15).
As a general rule, the airway cart should contain at least one al-
ternative for the difficult airway. The rescue device should allow
for the restoration of ventilation and oxygenation in the event that
endotracheal intubation is not possible and mask ventilation is mar-
ginal or not possible. This category includes nonsurgical and surgi-
cal approaches as outlined in Table 4.
Medications. Medications are used to attenuate deleterious re-
flex autonomic responses to airway manipulation and to render the
patient unconscious and amnesic. Neuromuscular blockade is pro-
vided to optimize laryngeal visualization and to prevent coughing.
Emergency clinicians should be intimately familiar with the com-
monly used medications, side effects, routes of elimination, and
pharmacokinetic profiles. The Broselow-Luten tape (Armstrong
Medical Industries, Lincolnshire, IL) allows for accurate dosing for
patients if their weight is not known or if the clinician cannot im-
mediately recall the dose (16).
Premedication. Premedication may be conveniently grouped
into 4 categories and remembered by the acronym LOAD (17).
Lidocaine is most commonly used as an intravenous medication
for the purpose of suppressing reflex autonomic and airway re-
sponses to laryngoscopy and endotracheal intubation. Lidocaine at-
tenuates increases in intracranial pressure during laryngoscopy in
110 PEDIATRIC EMERGENCY CARE April 2002
TABLE 4Suggested airway cart equipment for the emergency department
Laryngoscope blades of all sizes and styles and Magill forcepsEndotracheal tubes of all sizes, cuffed and uncuffedCO2 detector (adult and pediatric)Facemasks (neonate to adult)All sizes of naso- and oropharyngeal airwaysSuction equipment and catheters
Self-inflating resuscitation bagsEndotracheal tube guides
Semi-rigid intubating stylet (some hollow variants facilitate jetventilation)
Light wandFlexible fiberoptic intubation equipmentEmergency nonsurgical ventilation
Transtracheal jet ventilationLaryngeal mask airwayTracheoesophageal combitube
Emergency surgical airway accessCricothyrotomy equipment
Needle (14-gauge catheter over needle, 3.0 ID endotracheal tubeadapter)
Seldinger kits available for children younger than 910 years
The expertise and experience of the ED clinician should dictate the con-
tents of the airway cart.Adapted from Practice guidelines for management of the difficult airway:a report by the American Society of Anesthesiologists Task Force on theManagement of the Difficult Airway. Anesthesiology 1993; 78:597602.
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children with intracranial hypertension. It is given as an intra-
venous bolus of 1 to 2 mg/kg 2 to 3 minutes before laryngoscopy,
and it has direct anesthetic properties on the central nervous system
(17). Lidocaine can also be nebulized or sprayed onto airway struc-
tures or into the trachea to diminish the patients response to laryn-
goscopy and intubation. Concentrations of 1%, 2%, and 4% can be
given in volumes calculated to keep the total dose below the toxic
limit of 5 mg/kg.Opioids and benzodiazepines do not reliably produce uncon-
sciousness unless they are administered in large quantities. In such
doses, they often also produce apnea. As such, these medications
are best used as adjunct therapies for amnesia and analgesia with
other induction drugs. Additionally, these medications may be used
for conscious sedation in the spontaneously breathing patient who
is to be kept awake and responsive during endotracheal intubation.
Opioids produce sedation and blunt the response to noxious airway
stimuli, whereas benzodiazepines induce sedation and amnesia.
After adequate topical anesthesia of the airways, short-acting med-
ications such as midazolam in 0.05 to 0.1 mg/kg increments and
fentanyl in 1 to 2 g/kg increments can be given to render the pa-
tient less anxious and more comfortable.
Synergistic respiratory depression results from concomitant ad-ministration of opioids and benzodiazepines; however, with careful
titration of these medications, it is possible to avoid respiratory de-
pression. Should respiratory depression or excessive somnolence
occur, these are the only medications for which reliable and rapid
antagonists exist and allow reversal if spontaneous ventilation is
threatened. Slow titration of these agents will allow the clinician to
avoid excessive respiratory depression and the chest wall rigidity
that has been described with the rapid administration of large quan-
tities of fentanyl to children (18). Owing to differences in drug pro-
tein binding, central nervous system perfusion and permeability,
and receptor affinity, the risk for respiratory depression and apnea
is greater in neonates (1921).
Anticholinergic medications including glycopyrrolate, scopol-
amine, and atropine have several applications in the managementof the difficult pediatric airway. They cause tachycardia and drying
of oral secretions, and scopolamine also causes amnesia. Neonates
have a tendency to respond to laryngoscopy or hypoxemia with a
dramatic slowing of the heart rate as a result of parasympathetic
nervous system activation. Because stroke volume cannot be aug-
mented appreciably in neonates, cardiac output is dependent on
heart rates that are neither excessively fast nor slow (22). Neonates
are, therefore, good candidates for premedication with anticholin-
ergic medications, especially when succinylcholine is used. Many
investigators recommend premedication with atropine for all chil-
dren younger than 10 years (17). Atropine sulfate in an intravenous
dose of 0.02 mg/kg with a minimum dose of 0.1 mg can be given
to prevent bradycardia during airway management. Atropine sul-
fate can also be given intramuscularly in a dose of 0.04 mg/kg. The
site of intramuscular injection affects the rate of response to at-
ropine, with lingual injection producing faster response than del-
toid or vastus lateralis injection (23). Anticholinergic medications,
such as glycopyrrolate (0.01 mg/kg), are given to dry oropharyn-
geal secretions to optimize visualization during fiberoptic tech-
niques of airway management. This is optimally given 30 minutes
before airway management is attempted and, therefore, may be of
limited use in emergency airway management. Scopolamine is also
a potent antisialagogue and has the added benefit of producing se-
dation and amnesia.
Defasciculating doses of nondepolarizing neuromuscular block-
ers (NMBs) are administered to patients for two reasons. Before
widespread availability of rapidly acting, nondepolarizing NMBs,
this priming dose of neuromuscular blocker would allow for
much more rapid onset of paralysis if the patient received one tenth
of the usual intubating dose (ie, pancuronium) 3 to 5 minutes be-
fore administration of the customary intubating dose (24). This is a
less common concern today with the availability of medications
such as mivacurium, rocuronium, and rapacuronium.
The second reason to administer a fraction of the usual dose of anondepolarizing NMB is to attenuate the fasciculations commonly
seen with the administration of succinylcholine. Although the
mechanism is not clear, elevations in intracranial and intraocular
pressure occur contemporaneously with fasciculations and may be
attenuated by prior administration of a defasciculating dose of non-
depolarizing NMBs (17, 25). Some patients may experience
diplopia, muscle weakness, and a sense of difficulty breathing re-
sulted from the weakness induced by this dose. It is therefore pru-
dent to try to render the patient amnesic to preintubation events and
to be prepared to quickly secure the airway should these symptoms
become problematic.
Other medications useful for airway management include a topi-
cal vasoconstrictor to minimize the risk of epistaxis during nasal ap-
proaches. Naloxone, 12 g/kg intravenously repeated as needed torestore adequate respiratory drive without excessively reversing se-
dation, and flumazenil (0.0050.01 mg/kg) are useful for reversing
excessive respiratory depression caused by benzodiazepines and opi-
oids when used in awake attempts at airway management during
spontaneous ventilation (26). Repeated doses may be needed to treat
recurrent respiratory depression, because the half-lives of these an-
tagonists are generally shorter than the drugs they are designed to
antagonize.
NEUROMUSCULAR BLOCKERS. The purpose of NMBs is to
provide complete muscle relaxation to facilitate endotracheal in-
tubation. These drugs differ in their onset times, duration of ac-
tion, side effects, and routes of metabolism. Succinylcholine, mi-
vacurium, and rocuronium provide alternatives for all situations
in the ED.DEPOLARIZING NEUROMUSCULAR BLOCKADE. Succinylcholine is
a depolarizing NMB that produces reliable intubating conditions in
the shortest amount of time. In children, an intravenous dose of 2
mg/kg (45 mg/kg intramuscularly) produces intubating conditions
within 30 to 45 seconds (46 min after intramuscular injection) (24).
In older children, the onset of paralysis is heralded by skeletal mus-
cle fasciculation, which is usually not seen in infants. The principal
benefit of neuromuscular blockade is that most patients will recover
from it in approximately 5 to 7 minutes. Thus, neuromuscular block-
ade is ideal for rapid sequence intubation (RSI) and for use in the dif-
ficult airway.
In emergencies where succinylcholine is believed to be the best
drug for airway management, there should little reservation about
using it. However, there are relative contraindications to its use,
which are outlined in Table 5. The tendency to elevate serum
potassium levels is of little clinical relevance in most patients.
However, patients with burns, denervating nerve injuries (eg,
stroke, spinal cord injury), crush injury, intra-abdominal abscess,
and myopathy are at risk for marked elevations in serum potas-
sium that can result in cardiac arrest (2729). Hyperkalemia does
not seem to be problematic in patients with cerebral palsy or
myelomeningocele (30, 31). For acquired risk factors (eg, burns,
denervating injuries), it is recommended that succinylcholine be
avoided for the period between 1 and 2 days to 6 months to 2
years after the injury (32).
There is also concern that succinylcholine administration will ex-
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acerbate intracranial hypertension or elevate intraocular pressure in
patients with an open eye injury. Elevations in intraocular and in-
tracranial pressure occur contemporaneously with the skeletal mus-
cle fasciculations that follow succinylcholine administration, but themechanism of pressure elevation is not known. It is also unclear
whether small children (younger than 6 to 8 years) possess adequate
muscle mass to produce substantial fasciculations, and substantial
fasciculations are not commonly seen in infants (24). Despite this,
many clinicians believe that administration of a defasciculating dose
of a nondepolarizing NMB (10% of the usual intubating dose) may
help to attenuate these deleterious effects (17, 25). It is reasonable
to administer this nondepolarizing NMB dose 1 to 3 minutes before
succinylcholine administration if intracranial hypertension or in-
traocular pressure is of concern.
Succinylcholine may also cause arrhythmias in children, particu-
larly bradyarrhythmias, after intravenous injection. Succinylcholine
structurally resembles two acetylcholine molecules bonded together,
and it has a tendency to act as a muscarinic surge at the parasympa-thetic receptors on the heart. Children are particularly prone to the
vagal effects of succinylcholine, and this drug should probably al-
ways be preceded by intravenous atropine in children in the ED (33).
Atropine premedication may be less critical when succinylcholine is
administered intramuscularly (34).
NONDEPOLARIZING NEUROMUSCULAR BLOCKADE. Mivacurium
is a nondepolarizing NMB that represents a reasonable compro-
mise between succinylcholine and other NMBs. Mivacurium in
an intravenous dose of 0.3 mg/kg provides muscle relaxation (al-
beit sometimes weak relaxation) in 60 to 90 seconds and provides
clinical relaxation for 8 to 15 minutes in the absence of pharma-
cologic antagonism. Recovery to 25% of baseline twitch height is
evident in 6 minutes in infants and in 10 minutes in children (35,
36). Like succinylcholine, mivacurium is dependent on plasma
cholinesterase for elimination, but, unlike succinylcholine, it can
be antagonized with neostigmine. Rapid administration causes
histamine release. The intensity of neuromuscular blockade with
this drug has been somewhat variable and less complete than suc-
cinylcholine.
Rocuronium is a nondepolarizing NMB that produces strong
muscle relaxation in 30 to 45 seconds to just over 1 minute when
administered in a dose of 0.6 to 1.2 mg/kg intravenously (higher
doses for RSI conditions). Rocuronium is similar to succinyl-
choline in its ability to produce favorable RSI conditions (37);
likewise, it is of rapid onset, but its duration of effect tends to be
about 30 to 45 minutes. The return of the first twitch in the train of
four returns in approximately 17 minutes and can be pharmacolog-
ically antagonized with neostigmine if necessary (37). Like suc-
cinylcholine, rocuronium can be administered intramuscularly in
the absence of intravenous access (38). In high doses, it sometimes
causes tachycardia. Rocuronium is best used for RSI when there is
a reason to avoid succinylcholine, and the airway is not anticipated
to be difficult. Rocuronium is metabolized and excreted by the liver
and can be antagonized by neostigmine.SEDATIVE AND INDUCTION DRUGS. Sedative and induction drugs
produce unconsciousness and amnesia and facilitate endotracheal
intubation. A detailed discussion of the pharmacodynamics and
pharmacokinetics of the induction agents is beyond the scope of
this report, but the salient features are reviewed briefly. Sodium
thiopental (STP) reliably produces unconsciousness, amnesia, and
apnea in induction doses of 4 to 7 mg/kg intravenously (40).
Lower doses are required in neonates because of decreased protein
binding (41). The clinical effects of STP dissipate rapidly because
of redistribution from the central nervous system to fat and mus-
cle, which explains why a medication with an elimination half-life
of 3 to 10 hours in children is clinically effective for only 20 min-
utes (42). After repeated doses of STP are administered, saturation
of muscle and fat sites occurs and redistribution no longer takesplace.
Induction doses of STP lower intracranial pressure more than
mean arterial pressure (43). Thus, cerebral perfusion pressure is pre-
served or improved, whereas the medication decreases the cerebral
rate of oxygen consumption (43). STP is also a potent antiepileptic
drug even in small doses, but it is of short duration because of redis-
tribution. STP is a direct myocardial depressant, causing tachycardia
by a central vagolytic mechanism, venous capacitance vessel pool-
ing of blood, and reduced cardiac output (43). Patients with car-
diomyopathy, profound hypovolemia, and insufficient baroreceptor
reflexes can experience profound hypotension from customary in-
duction doses of STP. Therefore, if STP is to be used in these cir-
cumstances, smaller doses should be titrated cautiously.
Ketamine can be considered to be the opposite of STP with re-spect to its hemodynamic profile. Its usual intravenous dose of 1 to
2 mg/kg increments produces dissociative analgesia and amnesia.
Intramuscular administration is unpredictable, but an intramuscular
dose of 4 to 6 mg/kg is usually sufficient. Ketamine increases heart
rate, blood pressure, and cardiac output through its stimulation of
central sympathetic nervous system outflow (26). It is a direct myo-
cardial depressant (44) and must be used with caution in patients
with depleted catecholamine reserves (severe end-stage shock) in
whom deleterious hemodynamic effects may be observed. As op-
posed to all of the other induction drugs, respiratory drive is rela-
tively preserved with ketamine (26), although intact laryngeal re-
flexes cannot be presumed to be present. Patients ventilate
spontaneously, which makes this an attractive sedative for proce-
dures in unintubated patients in whom it is preferable to maintain
spontaneous ventilation. However, preservation of spontaneous
ventilation cannot be assured in neonates receiving ketamine or in
older children who are premedicated with large doses of opioid
medications. Ketamine is a potent bronchodilator and may be the
drug of choice for intubation of the severe asthmatic. As a potent
sialogogue, however, concomitant administration of an anticholin-
ergic medication should be considered to prevent copious airway
and salivary secretions. In contrast to STP, the central nervous sys-
tem effects of ketamine include increased cerebral metabolic rate,
intracranial pressure, and cerebral blood flow (43). As such, it is a
poor choice for the patient with increased intracranial pressure.
Emergence delirium is less common in children than adults. How-
112 PEDIATRIC EMERGENCY CARE April 2002
TABLE 5Selected potential deleterious effects
associated with the use of succinylcholine
HyperkalemiaMyopathyHistory of malignant hyperthermiaDenervating injury or disease process ( 23 d, lasting for 36 mo or
longer)
Recent burns (more than 24 h and less than 6 mo since injuryriskbelieved to decrease with healing)
Crush injuriesAbdominal abscesses
ArrythmiasIncreased intracranial pressureIncreased intraocular pressureMyalgiasIncreased intragastric pressure
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ever, premedication with a benzodiazepine is an effective way to
attenuate this side effect.
Etomidate incorporates the best of STP and ketamine. Etomidate,
in an induction dose of 0.3 to 0.4 mg/kg intravenously, preserves car-
diovascular stability (45, 46), producing minimal changes in blood
pressure, cardiac output, or systemic vascular resistance. It results in
less respiratory depression than barbiturates, and it decreases cere-
bral metabolic rate of oxygen, intracranial pressure, cerebral bloodflow, and maintains cerebral perfusion pressure (43). Etomidate may
potentiate seizure foci in patients with seizure disorders (47, 48). Pre-
vious investigators have demonstrated increased mortality among
patients receiving prolonged infusions of etomidate for sedation (49).
Etomidate transiently inhibits the enzymes responsible for the syn-
thesis of adrenal steroids (49), and both induction doses and long-
term infusions may cause reversible adrenal insufficiency (50, 51).
However, this is not likely to be of clinical significance during use in
the ED. Etomidate is a good choice for induction of anesthesia in pa-
tients who are critically ill with unknown circulatory or central ner-
vous system disease.
Benzodiazepines, including midazolam, diazepam, and loraze-
pam, are commonly used in the ED to provide sedation and amne-
sia during airway management. Benzodiazepines are attractive be-cause of their antiepileptic properties and the relative hemodynamic
stability that they provide. One should be cautious, however, when
they are used with opioids or other sedative hypnotic medications,
because this may produce synergistic respiratory depression.
BASIC AIRWAY MANAGEMENT
Schematic approaches to the pediatric airway are outlined in Fig-
ure 1. For practical purposes, the pediatric airway in the ED can be
classified into three categories: the uncomplicated airway, the ob-
viously difficult airway, and the difficult airway that is not antici-
pated.
Any approach to securing the childs airway must be simple and
likely to be successful on first attempt. Individual practitioner pref-erence, familiarity, and confidence should dictate the options avail-
able in a given ED. Although it is necessary to be familiar with all
of the approaches, it is critical to be particularly adept at a few.
Figure 1A depicts a global approach to the pediatric airway and
emphasizes the importance of recognition of the difficult airway
(defined as an airway predicted to be difficult to mask ventilate and
intubate) before administering sedating or paralyzing drugs. Figure
1B outlines the approach to the straightforward pediatric airway
and advocates rapid sequence induction or modified rapid sequence
induction for most pediatric patients with uncomplicated airways.
It also provides escape arms for lost airways (unable to mask ven-
tilate or intubate) and the unrecognized difficult airway (able to
mask, unable to intubate).
The difficult airway algorithm (Fig. 1C) provides some recom-
mendations for an approach to the airway that is known to be diffi-
cult. It emphasizes the importance of maintaining spontaneous ven-
tilation if the patient is fairly stable. The patient can remain
conscious and breathing spontaneously, or sedatives can be titrated
to help manage the less cooperative patient. The sedatives used
should be easily reversible if drug-induced respiratory compromise
occurs.
The lost airway algorithm (Fig. 1D) provides some recommenda-
tions for airway management if bag-mask ventilation or intubation is
not possible, and spontaneous ventilation is inadequate or absent.
This algorithm recognizes the difficulty in pediatric transtracheal
techniques and offers the clinician the opportunity to decide whether
airflow obstruction during mask ventilation can be bypassed by in-
troducing a laryngeal mask airway (LMA) or Combitube (Kendall,
Mansfield, MA) (for larger children). If this is unsuccessful or un-
available, the next step is to proceed immediately to invasive airway
management. For the profoundly hypoxemic patient who is in ex-
tremis, the clinician should proceed directly to needle cricothyrot-
omy in children, because this is the technique that is most likely to be
rapidly successful.The final algorithm, the crash airway algorithm (Fig. 1E), pro-
vides some recommendations for airway management in the patient
who is critically ill or unstable. It acknowledges that it may not be
necessary to provide pharmacologic assistance for the patient who
is already moribund and unlikely to react to or recall the airway in-
tervention. We advocate immediate initiation of bag-mask ventila-
tion before the first attempt at endotracheal intubation. This may
restore some physiologic stability and prevent or forestall cardio-
vascular collapse. Likewise, for the patient with intracranial hyper-
tension, mask ventilation is the most effective in rapidly lowering
intracranial pressure and improving cerebral blood flow. We sug-
gest using STP or etomidate plus lidocaine and a muscle relaxant if
the patient is moribund and intracranial hypertension is present. For
other patients, laryngoscopy and intubation can be performed with-out pharmacologic assistance.
It should be emphasized that algorithms are helpful; however,
clinical judgment, experience, and expertise should guide the indi-
vidual approach. Maintaining spontaneous ventilation (if it is phys-
iologically adequate) in the difficult airway scenario is critical. Fi-
nally, it is important to recognize when airway interventions are
ineffective. At this point, failure to proceed to another translaryn-
geal or transtracheal form of support may result in an adverse pa-
tient outcome.
The single most valuable asset available to the clinician is profi-
ciency at bag-mask ventilation. This is the technique that will buy
time and preserve life while other airway equipment, personnel, and
techniques can be mobilized. Poor technique results in hypoventila-
tion, gastric insufflation with air, and subsequent aspiration of gas-tric contents. Good technique involves preserving good maskface
seal, inflating the chest with the minimal required pressure, main-
taining the optimal patency of the upper airway through manipula-
tion of the mandible and cervical spine (when not contraindicated),
and insertion of oropharyngeal or nasopharyngeal airways (when
not contraindicated) to maintain patency of the upper airway. Good
mask technique, positioning, and gentle cricoid pressure are re-
quired to help minimize the risks of gastric aspiration. Cricoid pres-
sure must be applied gently (depress the trachea 12 cm) in infants,
because the pliable trachea can be completely occluded by the Sell-
ick maneuver if performed with too much pressure.
In most children, placement of the endotracheal tube under direct
visualization with the RSI technique is all that is needed. All at-
tempts at direct laryngoscopy should be gentle and brief. Failure to
do so will result in further airway bleeding and edema and may ex-
acerbate intracranial hypertension. Indeed, the most common sce-
nario leading to severe injury in lost airway scenarios is progressive
airway compromise as a result of repeated iatrogenic trauma and
failure to abandon a technique that has proven to be ineffective.
The Uncomplicated Pediatric Airway. Patients in the ED
can generally be assumed to have a full stomach. Rapid sequence
induction is an airway strategy that is designed to minimize the risk
of aspiration of gastric contents. In this scenario, the patient is pre-
oxygenated by breathing spontaneously, and induction drugs and
paralytics are injected in rapid sequence. The patient is allowed to
become apneic without ventilating with positive pressure. As soon
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114 PEDIATRIC EMERGENCY CARE April 2002
A
B
FIG. 1. A, Global algorithm for pediatric airway management in the emergency department.B, Management of the straightforward pediatric airway. (continued)
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Vol. 18, No. 2 SECURING THE CHILDS AIRWAY IN THE ED 115
FIG. 1. (Continued) C, Difficult airway algorithm. Options for endotracheal tube placement while the patient is breathing spontaneously include, but are notlimited to, awake direct laryngoscopy, blind nasal (children 10 y), fiberoptic methods (Bullard, flexible bronchoscope), intubating laryngeal mask airway, lightwand, retrograde techniques.D, Lost airway algorithm. (continued)
C
D
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116 PEDIATRIC EMERGENCY CARE April 2002
as the patient is paralyzed and sedated, the clinician performs direct
laryngoscopy and places the endotracheal tube under direct visual-
ization while an assistant provides gentle cricoid pressure (Sellickmaneuver). This technique provides optimal conditions for endo-
tracheal intubation and minimizes the risk of gastric aspiration. It
should be the technique most commonly used in the ED.
Rapid sequence induction may require modification when ap-
plied to younger children, especially infants and those with severe
lung pathology, because they are likely to desaturate quickly. In this
setting, a modified rapid sequence induction is selected. After pre-
oxygenation, a sedative and paralytic medication is given intra-
venously as cricoid pressure is gently applied. The airway is gently
ventilated with positive pressure until laryngoscopy and endotra-
cheal intubation. This prevents, or minimizes, the arterial oxygen
desaturation associated with brief periods of apnea in the sick infant.
The Obviously Difficult Airway. The child with a history or
physical findings suggestive of a difficult airway presents the clin-ician with the opportunity to avoid the pitfalls associated with a sit-
uation in which intubation and ventilation are impossible. Patients
with obviously difficult airways include those with syndromes as-
sociated with abnormal airway anatomy and those with abnormal
airways resulting from trauma or airway inflammation (eg, epiglot-
titis, caustic ingestion, or thermal injury). The approach to airway
management is dictated by the urgency of the patients condition
and the perceived difficulty the airway presents.
If it is likely that bag-valve-mask ventilation will be successful,
drugs that will abolish respiratory drive or paralyze the respiratory
muscles should not be given. In such instances, it is preferable to
secure the airway with the patient breathing spontaneously. Op-
tions for accomplishing this include generous topical airway anes-
thesia followed by awake laryngoscopy, fiberoptic bronchoscopy,
blind nasotracheal intubation, light wand intubation, and retrogradetechniques. The choice of technique will depend on the preference
and confidence level of the practitioner, age and degree of cooper-
ation of the child, and the specific clinical circumstances. It may
also be appropriate to involve other health care professionals
skilled in airway access to assist if time permits.
For patients who are likely to be easy to bag-mask ventilate, but dif-
ficult to intubate endotracheally, other approaches are possible. In this
situation, the risk of gastric aspiration during airway manipulations
must be weighed against the increased cooperation gained by admin-
istering sedatives and/or paralytic agents. In agitated and uncoopera-
tive patients, the risk benefit ratio may favor sedation and/or paraly-
sis. The favorable conditions gained may more than offset the risk of
aspiration. In addition to the techniques described previously, the
spontaneously breathing patient can also be taken to the operatingroom and intubated while spontaneously inhaling volatile anesthetics.
In the ED there will be patients with difficult airways and limited
physiological reserve who are in need of immediate airway access.
Approaches in such a setting include the quick confirmation that
one can neither mask ventilate nor endotracheally intubate the
patient. If neither can be done, it is appropriate to place a tempo-
rizing airway (eg, LMA, Combitube) or proceed directly to an in-
vasive airway technique.
Options for invasive airway management in children in the ED in-
clude needle cricothyrotomy and/or placement of a larger cricothy-
roid tube via the Seldinger technique. Needle cricothyroidotomy is
the easiest and safest technique for temporary ventilatory support in
E
FIG. 1. (Continued) E, Crash airway algorithm. Adapted from Walls RW. The emergency airway algorithms. In: Manual of emergency airway management.Philadelphia: Lippincott Williams & Wilkins, 2000;1626.
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the ED and should be considered the technique of choice. The tech-
nique for gas exchange is dictated by patient age. Bag ventilation or
transtracheal jet ventilation (TTJV) with the pressure regulator set to
a low pounds per square inch (PSI) can be used to temporarily restore
oxygenation while a more definitive airway is pursued (52). How-
ever, TTJV should be used only by those who are skilled and com-
fortable with the technique.
Despite all of the opinions and reviews written on this subject,few clinicians actually have experience applying technique in chil-
dren. The cricothyroid membrane is small and may be difficult to
palpate in infants and smaller children. In such instances, it is ap-
propriate to place an intravenous catheter through the trachea in the
region of the cricothyroid membrane. Oxygenation and life-
sustaining levels of ventilation can be sustained for an hour or more
in dogs with nearly complete upper airway obstruction. Gas ex-
change was provided by low-flow oxygen in spontaneously breath-
ing animals and by positive pressure ventilation with a self-filling
bag in paralyzed animals (53).
Needle cricothyrotomy in children is a temporary measure and
is used to preserve oxygenation until a definitive airway can be ob-
tained. Although oxygenation may be preserved at life-sustaining
levels with this technique, ventilation is often marginally adequatefor a finite time period, and careful attention must be paid to the
rise and fall of the chest and oxygenation. Complete, or high-grade
proximal airway obstruction, can result in inadequate exhalation
and air trapping, leading to barotrauma and pneumothoraces.
Complications from errant placement of the needle and catheter
include pneumothorax, subcutaneous emphysema resulting in the
loss of favorable conditions for subsequent attempts at correct
catheter placement, mediastinal emphysema, esophageal injury,
and bleeding. In addition, ventilation with a self-filling resuscita-
tion bag may be difficult because of the high resistance imposed
by the small intravenous catheter in the airway. It may be neces-
sary to disable the pop-off valve on the self-filling bag to optimize
ventilation. Finally, TTJV requires the use of specialized equip-
ment and may cause injury if used improperly (54). Careful mon-itoring of the rise and fall of the chest, oxygen saturations, and
carbon dioxide tensions on blood gases is mandatory. Tracheos-
tomy (with surgical consultation in ED or operating room) or
translaryngeal endotracheal intubation from above can then be at-
tempted after oxygenation is ensured by needle cricothyrotomy.
Commercial kits are available for needle cricothyrotomy with sub-
sequent passage of a guidewire into the trachea, passage of serial
dilators, and placement of a cricothyrotomy tube. The wider bore
cricothyrotomy tube is much more able to facilitate ventilation
than the needle catheter; however, such kits exist only for children
older than 10 years.
The Unanticipated Difficult Airway. Despite attempts to
screen for and predict airway difficulties, the difficult airway may
be first recognized during the laryngoscopy phase of RSI. The next
step is to immediately determine whether the patient can be venti-
lated with bag and mask. If the patient can be ventilated, the tech-
niques available include optimizing the position and allowing the
most skilled individual present to repeat laryngoscopy. If the pa-
tient cannot be intubated, alternative techniques of airway manage-
ment include fiberoptic intubation, Bullard laryngoscopy, light
wand, retrograde techniques, and placement of LMA with blind or
fiberoptic placement of an endotracheal tube through the LMA.
Other options are needle cricothyrotomy with bag or transtracheal
jet ventilation or the placement of a cricothyrotomy tube via the
Seldinger technique (patient age and size permitting).
If the patient cannot be ventilated, urgent action is needed to es-
tablish ventilation. In rapid succession, this includes calling for
help, placement of oral and nasal airways (when not contraindi-
cated), and two-hand mask grip with optimization of sniffing posi-
tion and forward mandible displacement (observing c-spine precau-
tions when indicated) while an assistant squeezes the resuscitation
bag. If air cannot be moved effectively, the clinician must quickly
decide whether the airway obstruction can be remedied with LMA
placement or tracheoesophageal Combitube placement (if the pa-tient is an appropriate candidate for this device). Generally speak-
ing, pathology at the level of the supraglottis or below may not be
bypassed with these modalities, and it may be more prudent to pro-
ceed immediately to needle cricothyrotomy. Alternatively, older
children can be managed with placement of a cricothyrotomy tube
via Seldinger technique. For speed and simplicity, needle cricothy-
rotomy is probably the procedure that is most familiar to ED physi-
cians.
Review of Specific Techniques. Needle cricothyrotomy is
performed when anatomic injury prevents the movement of gas
from the upper airway into the trachea and the trachea cannot be in-
tubated via the translaryngeal route. A 14-gauge catheter over a
needle is introduced into the trachea in the region of the cricothy-
roid membrane. A syringe is attached to the needle and aspiratedfor free flow of air indicating entry into the trachea. With the
catheter firmly held in the trachea, the catheter is directly attached
to the endotracheal tube adapter from a 3.0 endotracheal tube. A re-
suscitation bag can then be attached to the catheter adapter assem-
bly, and oxygen can be insufflated into the lungs. Alternatively, the
barrel of a 3-cc syringe can be placed in the hub of the catheter, and
an endotracheal tube adapter from a 7.0 endotracheal tube can com-
plete the assembly for resuscitation bag attachment. An alternative
method for insufflating gas into the trachea is to connect a high-
pressure wall source (50 PSI) to the catheter via a hand-operated jet
injector with a pressure regulator gauge apparatus to prevent baro-
trauma. For children younger than 5 years, needle cricothyrotomy
with bag ventilation is the technique of choice (55). For children
between the ages of 5 and 10 years, options include needle cri-cothyrotomy with bag ventilation or TTJV with the pressure regu-
lator set to a low PSI that is sufficient to inflate the chest. For chil-
dren older than 10 years, the patients size may allow the clinician
to place a larger bore cricothyroid tube from commercially avail-
able kits, such as TTJV catheters or Seldinger cricothyroid sets
(Cook Critical Care, Bloomington, IN) (52).
The LMA is a recent addition to the difficult airway algorithm
presented by the American Society of Anesthesiologists (55) and
has recently been suggested for pediatric advanced life support by
the American Heart Association (56). The LMA consists of a wide
bore tube with a standard 15-mm adapter at the proximal end for at-
tachment to a breathing circuit or resuscitation bag. The distal end
is an elliptical mask that is inflated through a pilot balloon and con-
forms to the shape of the larynx. It provides a low-pressure seal for
mask ventilation at the level of the larynx (Fig. 2).
The advantage of the LMA is that it can effectively bypass the
supraglottic structures and can free the clinicians hands for further
airway endeavors. It also serves as an effective conduit for placement
of a fiberoptic bronchoscope into the trachea, because the LMA
opening is at the entrance of the glottis. LMAs come in varying sizes
and can be used in the smallest of pediatric patients (Table 6). LMAs
designed to facilitate fiberoptic intubation through the LMA are now
available with a modified laryngeal aperture with a movable flange
designed to lift the epiglottis from the path of the bronchoscope.
The LMA provides no more airway protection than a simple face-
mask. Patients may aspirate gastric contents, and the low-pressure
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seal may make ventilation difficult in patients who require elevatedinflating pressures because of obesity or intrinsic lung disease.
Placement of the LMA requires more sedation or anesthesia than
placement of an oral or nasal airway, and practice is required to be
proficient at proper placement and use of this instrument. Inability
to ventilate through the LMA is either a result of downfolding of the
epiglottis over the glottis during LMA placement or obstruction be-
low the level of the glottis.
The tracheoesophageal Combitube can be very helpful in allowing
ventilation and oxygenation to be preserved when mask ventilation
is difficult. The Combitube is a cylindrical device with two separate
lumens and two separate 15-mm airway adapters at the proximal end.
One of the lumens (white) serves as an endotracheal tube if the de-
vice should end up in the trachea as it is passed blindly through the
mouth. There other lumen (blue) has a sealed distal end and proximal
fenestrations to allow air to be delivered to the region of the glottis
by bag mask. A proximal balloon is inflated in the hypopharynx to
provide an adequate airway seal to permit ventilation. With the de-
vice placed blindly into the espohagus it serves the function of an
LMA, and the endotracheal tube lumen (white) can be used to facil-
itate passage of a nasogastric tube to evacuate the stomach (Fig. 3).
The Combitube has the disadvantage of being available in only one
size and is, therefore, helpful only in adolescents (patients older than15 years and5 ft tall) and has the potential to cause esophageal in-
jury in patients with esophageal pathology.
Although patients sometimes cannot be ventilated by mask or
118 PEDIATRIC EMERGENCY CARE April 2002
TABLE 6Suggested sizes for laryngeal mask airways in children
Mask size Patient size Weight (kg) Cuff volume (mL)
1 Infant 6.5 2 to 42 Child 6.520 102.5 Child 2030 153 Small adult 30 20
4 Normal and large adult 30Reprinted with permission from Morgan GE Jr, Mikhail MS. Airway
management. In: Clinical anesthesiology, ed 2. Stamford, CT: Appletonand Lange, 1996; 5072.
FIG. 3. Tracheoesophageal Combitube placed in esophagus or tracheacan provide emergency ventilation.A, The tracheoesophageal Combitubehas two lumens and two cuffs. B, If placed in the esophagus, ventilationthrough the blind tube will force gas out the side perforations and into thelarynx. C, If placed in the trachea, ventilation through the patent clear tubewill direct gas into the trachea. Reprinted with permission from Morgan GEJr, Mikhail MS. Airway management. In: Clinical anesthesiology, ed 2.Stamford, CT: Appleton-Lange, 1996;59.
A
B
FIG. 2. A, Laryngeal mask airways (LMA) of different sizes. B,Schematic drawing of proper placement of LMA: side view of LMA (A),insertion of LMA with head in sniffing position while pressing devicealong hard palate (B), advancement of LMA against posterior pharynx un-til seated (C), correctly seated LMA (D). Reprinted with permission fromMorgan GE Jr, Mikhail MS. Airway management. In: Clinical anesthesiol-ogy, ed 2. Stamford, CT: Appleton-Lange, 1996; 56.
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LMA, it is more likely that the patient can be ventilated to some de-
gree but cannot be intubated by the translaryngeal route under di-
rect visualization. This is common in patients with cervical spine
trauma, cervical spine fusion, limited mouth opening, and other
anatomic reasons contributing to the clinicians inability to align
the oral, pharyngeal, and laryngeal axes. In this situation, transla-
ryngeal tracheal intubation is possible via the blindor indirect vi-
sualization techniques.Indirect visualization techniques allow the clinician to see the
larynx indirectly using flexible fiberoptic bronchoscopy or a
Bullard laryngoscope. The Bullard laryngoscope is available in
adult and pediatric sizes (Fig. 4) and consists essentially of a
fiberoptic apparatus mounted on a handheld, L-shaped frame. It is
inserted into the oropharynx and allows the airway structures to
be directly visualized while the preloaded endotracheal tube is
passed off a wire stylet through the glottis under indirect visual-
ization. This can be done when the patient is awake (with topical
anesthesia) or asleep with either spontaneous or positive pressure
mask ventilation (asleep and paralyzed). Flexible fiberoptic intu-
bation entails the use of a variety of sizes (outer diameter and
length) of fiberoptic bronchoscopes over which an endotracheal
tube has been loaded. The bronchoscope can be introduced intothe airway via the oral or nasal routes and, likewise, can be done
when the patient is awake, asleep and breathing spontaneously, or
asleep and paralyzed. This can be accomplished via intermittent
attempts between mask ventilation with periods of apnea or it can
be performed through specialized facemasks that allow for con-
tinuous ventilation while flexible fiberoptic bronchoscopy is per-
formed.
Blindtechniques are methods in which the endotracheal tube is
placed into the trachea without direct or indirect visualization.
These techniques essentially include blind nasal techniques as well
as light wand intubations. Blind nasal intubation is easier in a spon-
taneously breathing patient. This technique involves the introduc-
tion of an endotracheal tube into the nasopharynx of the patient and
the advancement of the tube as the breath sounds in the endotra-cheal tube become louder. Commercially available endotracheal
tubes that incorporate a guiding ring and cable in the wall of the en-
dotracheal tube make it easy to direct the tube in an anterior direc-
tion for easier insertion. This technique is not advisable in patients
with potential basilar skull fracture. Techniques to facilitate seda-
tion with spontaneous ventilation include light benzodiazepine-
opioid sedation with topical airway anesthesia, inhalation anesthe-
sia, or ketamine-benzodiazepine methods. Blind nasal intubation is
not likely to be successful in small children because of the anterior
location of the glottis and the small laryngeal aperture that is ob-
scured by the epiglottis. This technique is not recommended for
routine use in children younger than 10 years (55).Light wand techniques involve passing an endotracheal tube
from an illuminated intubating stylet into the trachea without direct
or indirect visualization. The light wand has a very bright light on
its tip that is blindly passed through the glottic aperture. Placement
is attempted when a very bright light is visible through the skin
overlying the thyroid and cricoid cartilage. The main pitfall of this
technique is that, even with esophageal placement of the stylet, a
very bright light can sometimes still be seen through the anterior
neck. It is important to practice this technique to be able to reliably
distinguish between correct and incorrect stylet positions so as to
pass the endotracheal tube without displacing the stylet. This tech-
nique works better in anesthetized patients.
The final methods for translaryngeal intubation are collectively
referred to as retrograde techniques. This term encompasses a widevariety of permutations of maneuvers but in its distilled form refers
to the placement of a guidewire into the airway via the cricothyroid
membrane or trachea. The wire is passed proximally through the
laryngeal aperture and retrieved from the oropharynx. The wire is
passed through the Murphy eye of the endotracheal tube, and the
endotracheal tube is advanced into the trachea over the guidewire.
Alternatively, the guidewire can be passed through the working port
of a bronchoscope over which an endotracheal tube has already been
loaded. The bronchoscope and endotracheal tube combination is ad-
vanced over the guidewire and placed in the trachea under indirect
visualization. These techniques work best with generous topical air-
way anesthesia or after the induction of anesthesia.
CONCLUSIONS
Proper airway management requires practice and judgment in
addition to an appreciation of the anatomic, pharmacologic, and
physiologic differences that separate infants and children from
adults. It is prudent to become proficient at techniques for airway
management beyond simple direct laryngoscopy and endotracheal
intubation, even though most cases will require nothing more. The
clinician should strive to be familiar with many techniques, but
should become very adept at only a few.
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