Download Emergent evaluation of acute upper airway obstruction in children.

Upper airway obstruction in pediatric
patients from anesthesiologist vew
Prof. Mirjana Shosholcheva
University clinic of surgery “St. Naum Ohridski”
Medical faculty-Skopje, Macedonia
Disclosures
 No financial disclosures
 No conflict of interest
Key points
Causes of airway obstruction in children
Signs of airway obstruction
Airway obstruction with foreign body
Airway obstruction during emergence from anaesthesia
Management of laryngospasm
Securing the airway in a child with airway obstruction
Epidemiology and mortality
 Upper airway obstruction
accounts for up to 15%
pediatric emergency*
Failure to manage the
airway is the leading
cause of preventable
pediatric deaths
 The major causes are:
 Viral croup (80%)**
 Epiglotitis (5%)
 Foreign body
aspiration
Infants and children
decompensate more
quickly compared to
adults
* Loftis L. Emergent evaluation of acute upper airway obstruction in children.
Reprint from Up to date www.uptodate.com
** Manno M. Pediatric respiratory emergencies: Upper airway obstruction and infections. In: Marx J, ed.
Rosen's Emergency Medicine: Concepts and Clinical Practice . 7th ed. Philadelphia, Pa: Mosby Elsevier;
2009:chap 166
Important causes of airway obstruction in children
Laryngospasm after tracheal
extubation –major of UAO after surgery
Life-threatening emergency
Congenital
anomalies
Anaphylactoid
reactions
Depressed
conscious level
Postextubation
laryngospasm
Rapidly
progressive
Airway
obstruction
Infections
Thermal injury
Trauma
Airway
foreign body
*Morton NS. Large airway obstruction in children: causes, assessment
and management. Update Anaesthesia 2004; 18 (article 13):1
Signs of airway obstruction in children
unconscious or
sedated patient
conscious patient
-
marked respiratory distress
altered voice
dysphagia
the hand-to-the-throat choking sign
stridor, facial swelling
prominence of neck veins
absence of air entry into the chest
tachycardia
- inability to ventilate with
a bag-valve mask
- asphyxia progresses to cyanosis
-
bradycardia
hypotension
irreversible cardiovascular collapse
Obstructive noise or stridor is specific for UAO
Specifics regarding signs of airway
obstruction in children
 Mild upper airway
obstruction


child recovering from
anaesthesia
tonsillar hypertrophy and
obstructive sleep apnea
Signs of partial upper
airway obstruction
include biphasic snoring
and mild desaturation
 Severe, non-complete,
progressive airway
obstruction




increased work of breathing
respiratory failure
Hypoxemia
cardiac arrest
Children with severe
croup, tracheitis,
epiglottitis, airway burns
Trauma, depending on its severity and location, may produce
immediate or progressive obstruction
Signs of increased work of breathing
Tachypnea
Paradoxical respiration “See-saw” pattern of breathing
(dyssynchrony between rib cage and abdomen)
Suprasternal, intercostal, and subcostal retraction along with
an increased use of accessory muscles of respiration
auto CPAP
Position: Infants may assume an opisthotonic position; the
"tripod" or sniffing position is seen in the older child
Stridor
Inspiratory stridor
airway compromise at
the supraglotic or laryngeal level
Expiratory stridor
intrathoracic obstruction
The magnitude or severity of stridor does not correlate with the
severity of obstruction
Signs of ineffective breathing and respiratory failure:
Cyanosis
Altered consciousness
Bradypnea, apneic spelss
Silent chest in spite of vigorous effort
Compleet airway
Post-extubation laryngospasm,
angiooedema and
obstruction anaphylactoid reactions
Choking, absent breath sounds and aphonia
This rapidly progresses to cyanosis, bardycardia and cardiac arrest
Airway obstruction with foreign body
Foreign-body aspiration is a relatively frequent accident and
a leading cause of accidental death in children under 5 years of age
Diagnosis of foreign body aspiration should be suspected in
children who do not respond to appropriate
intervention
Laryngeal impaction is life-threatening
(large or sharperdged foreign bodies may lodge in the larynx)
Most foreign bodies pass the vocal
cords and lodge in the lower airways (bronchi -80%)
Symptoms can mimic other
diseases such as croup or asthma
Airway obstruction with foreign body
• Nasal foreign bodies
unilateral rhinorrhea and stinking breath
• Oropharyngeal foreign bodies :
mouth breathing
• Children with a history of choking and subsequent
symptoms must be referred to immediate bronchoscopy!
What about the child who has stridor and wheezing?
The causes of stridor and wheezing in older infants and children include
foreign bodies in the airway and in the esophagus
and combination of infectious causes
Management of airway obstruction
with foreign body
*if the child can cough and verbalized it is placed in
the position of comfort and oxygen is given
IV line placement and other interventions which may agitate
the child in this case are avoided
X-ray evaluation for localization can be performed
urgently in stable children
The presence of asphyxia indicates the need
for immediate resuscitation and securing the airway
*Schmidt H., Manegold BC. Foreign body aspiration in children. Surg Endosc 2000; 14:644-8
“Circulus viciosus”
BLS maneuvers
Most patients can
be discharged
within 24 h
(Heimlich, Guidel )
direct laryngoscopy
Complications
1. Mild oedema of the respiratory mucosa
2. Tracheobronchitis
3. granulation tissue
short course of
corticosteroids
rigid bronchoscopy
Magill forceps
or suction
flexible
bronchoscopy
Repeat
bronchoscopy
Child is in respiratory distress!
inhalational induction with 100% oxygen and sevoflurane
After loosing the consciousness. i.v. cannula
TIVA with propofol and fentanyl
gentle assistance with inhalational technique
cords are sprayed with local anaesthetic
rigid bronchoscope with a ventilating side arm is inserted,
facilitated by laryngoscopy
higher FiO2
Dexamethadone
The foreign body is withdrawn by a
forceps through the bronchoscope
Laryngeal edema might be worsening after multiple insertions of the rigid
bronchoscope, and post-procedure reintubation might be required
Securing the airway in a child with airway
obstruction – General considerations
Laryngoscopy and intubation
volatile anaesthetics
Sevoflurane might be choice, but its use has some controversy,
because lower potency of sevoflurane may not permit intubation
The Jackson-Rees modification of Ayer,s “T piece” circuit
- CPAP
Attempts to assist ventilation against complete obstruction
are usually futile!
Alveolar ventilation in these children is severely compromised. Uptake of volatile
agents is very slow and induction of anaesthesia may take more than 15 min
Any attempt at “asynchronous” assistance leads
to complete obstruction, especially in large
foreign bodies
“Synchronized” assistance (analogous to triggered ventilation)
is very helpful to maintain oxygenation
As the depth of anaesthesia increases, the
child may be gradually lowered to the
supine position
intubation is difficult or
impossible
flexible fiberoptic
bronchoscopy
If the condition of the child deteriorates,
cricothyrotomy and ventilation through
a T piece circuit can be considered
Jet ventilation is not appropriate as it may
lead to barotrauma
The safest option is emergent
tracheostomy under musk anaesthesia
for most children who cannot be
intubated in one or two attempts
Controversy associated with heliox therapy in UAO
Heliox has been used in several conditions:
postextubation laryngeal edema, tracheal stenosis or extrinsic compression,
status asthmaticus and angioedema
To be effective, the helium–oxygen ratio must be at least 70:30
Although the work of breathing and dyspnea improves to some
degree with the use of heliox, the mechanical obstruction is
still in place
The use of heliox in patients with severe UAO should only be
used to provide temporary support pending definitive
diagnosis and management
Algorithm for management of upper airway obstruction
Infective causes of airway obstruction
acute clinical syndrome of hoarse voice, barking cough and stridor
Endoscopic view of subglottic oedema
in viral croup
Radiological presentation of subglottic
oedema in viral croup (left) compared with
a normal trachea (right)
There is some controversy regarding treatment with epinephrine
Usually affects children from 6 months to 4 years of age,
with a peak incidence at 2 years of age
Epiglotitis
Schematic (left) and endoscopic view (right) of epiglottitis.
Lateral neck radiographs of a normal child (left)
and a child with epiglottitis with the typical thumb sign (right)
Conversely, epinephrine is not effective in the treatment of epiglottitis
and may be deleterious.
Controversy! To look or not to look
Airway burns
Heat produces an immediate injury to the airway mucosa  edema
Suspect for inhalation injury
Exposure in an enclosed space
Decreased level of consciousness, confusion
Soot in mouth, nares
Carbonaceous sputum
Swelling, ulceration of oral mucosa or tongue
Dyspnoea
Increased work of breathing
Hoarseness
Oxygen saturations <94% in air
Caboxyhaemoglobin >5% on co-oximetry
Stridor, wheeze, crepitations
Effect of deep face burns on airway maintenance are:
Airway obstruction by intraoral and laryngeal edema
Anatomic distortion by face and neck edema, which increases
the difficulty of endotracheal intubation
Oral edema decreasing clearance of intraoral secretion
Impaired protection of the airway from aspiration
Maintaining an adequate airway!
Maintain airway patency
Protect against aspiration
Pulmonary toilet to decrease mucous plugging and infection risks
Need for positive-pressure
When in doubt, it is safer to intubate!
TRAUMATIC LESIONS
Damage from endotracheal intubation and
tracheotomy
Even the dictum that ‘cuffed endotracheal tubes should not be used in
children under the age of 8 years’ can no longer be maintained
since the development of high-volume, low-pressure cuffs*
Endotracheal tube complications
incorrect size, traumatic or multiple intubations
up and down movements of the endotracheal tube
inadequate analgesia and sedation, whereby the infants
struggle while intubated
*Newth CJL, Rachman B, Patel N, Hammer J. The use of cuffed versus
uncuffed endotracheal tubes in pediatric intensive care. J Pediatr 2004; in press
Cuff vs Uncuffed Endotracheal Tube
Controversial issue
 Traditionally, uncuffed ETT recommended in children < 8 yrs old to
avoid post-extubation stridor and subglottic stenosis
 Arguments against cuffed ETT: smaller size increases airway
resistance, increase work of breathing, poorly designed for pediatric
patients, need to keep cuff pressure < 25 cm H2O
 Arguments against uncuffed ETT: more tube changes for long-term
intubation, leak of anesthetic agent into environment, require more
fresh gas flow > 2L/min, higher risk for aspiration
-
Concluding Recommendations
 For “short” cases when ETT size >4.0, choice of
cuff vs uncuffed probably does not matter
 Cuffed ETT preferable in cases of:
 high risk of aspiration (ie. Bowel obstruction),
 low lung compliance (ie. ARDS, pneumoperitoneum,
CO2 insufflation of the thorax, CABG),
 precise control of ventilation and pCO2 (ie. increased
intracranial pressure, single ventricle physiology)
Golden, S. “Cuffed vs. Uncuffed Endotracheal tubes in children: A review”
Society for Pediatric Anesthesia. Winter 2005 edition.
Laryngeal Mask Airway – WHEN?
Supraglottic airway device
 Flexible bronchoscopy, radiotherapy, radiologic
procedures, urologic, orthopedic, ENT and
ophthalmologic cases are most common pediatric
indications for LMA
 Useful in difficult airway situations, and as a conduit of
drug administration (ie. Surfactant)
 Different types of LMAs: Classic LMA, Flexible LMA,
ProSeal LMA, Intubating LMA
 Disadvantages: Laryngospasm, aspiration
Airway obstruction during emergence from anaesthesia
Postoperative
laryngospasm - lifethreatening complication
aspiration, airway obstruction
Tracheal
extubation
awake
deep anesthesia
Concern:light plane of anesthesia!
local irritation by
blood or saliva
light planes of anaesthesia
Child undisturbed - in the
lateral recovery position
Hypoventilation
Hypoxemia
Hypercarbia
Cardiac dysrhythmias
Cardiac arrest
Emergence and extubation: A systemic approach
Can this patient be extubated while deeply anesthetized?
Yes
No
- No rezidual NMB
- Easy musk ventilation
- Easily intubated
- Not at increased risk for
regurgitation/aspiration
- Normothermic
-
Difficult musk ventilation
Difficult intubation
Residual NMB present
Full stomach
Can this patient be extubated immediately following
surgery and emergence from general anesthesia?
Can this patient be extubated immediately following
surgery and emergence from general anesthesia?
Yes
No
- Hypoxic (O2 saturation < 90 mmHg)
Awake
- Excessively hyperbaric(Pa CO2 >50mm Hg
Following commands
- Hypothermic (< 34 C)
Breathing spontaneuosly
- NMB present
Wheel oxigenated
- Not excessively hyperbaric
- (PaCo2  50 mmHg
- Fully recovered from MR
- Sustained head lift
- Strong hand grip
- Strong tongue protrusion
-
Partial laryngospasm
complete laryngospasm
inspiratory stridor
absence of air movement
Tracheal tug and paradoxical (“see-saw”) movement of the abdomen
Increased airway problems
children with a history of a recent upper respiratory
tract infection
former premature infants
children with chronic, obstructive sleep apnea
Managament of laryngospasm
jaw thrust maneuver,
neck extension and
mouth opening
mild biphasic snoring-noisy breathing
placing the child in the “safe” position
oxygen by face mask
positive pressure with a bag and face mask may be required
along with a naso-pharyngeal airway
If necessary a dose of succinylcholine followed by tracheal reintubation (in children older than 2 years!!!)
Of particular concern have been the instances of lifethreatening malignant hyperpyrexia and reports of rare, but
often fatal, hyperkalaemic cardiac arrests in young boys with
undiagnosed muscular dystrophy.
As a result of these reports, in 1994, the US Food and Drug
Administration (FDA) recommended that
‘the use of succinylcholine in children should be reserved for
emergency intubation and instances where immediate
securing of the airway is necessary, e.g. laryngospasm,
difficult airway, full stomach, or for i.m. use when a
suitable vein is inaccessible’.
Since the publication of this recommendation, the use of
succinylcholine in routine anaesthesia in children has been
declined.
RISK OF CARDIAC ARREST FROM
HYPERKALEMIC RHABDOMYOLYSIS
This syndrome often presents as peaked T-waves and sudden cardiac arrest
within minutes after the administration of the drug in healthy appearing
children (usually, but not exclusively, males, and most frequently 8 years
of age or younger).
There have also been reports in adolescents.
Recent concerns about the elective use of succinylcholine in
pediatric patients have focused on the occasional reports of
hyperkalemic cardiac arrest, particularly in children with
undiagnosed Duchenne muscular dystrophy. The incidence
of Duchenne muscular dystrophy is only 1 in 3000 to 8000
male children. The revised labeling continues to permit the use
of succinylcholine for emergency control of the airway and
treatment of laryngospasm.
Succinylcholine is the only neuromuscular blocking agent
currently available that has been demonstrated to be effective
after intramuscular (IM) administration when emergency
control of the airway is required and there is no IV access. In
this circumstance, the dosage must be increased to 4 to 5 mg/kg
IM. Atropine is administered simultaneously. Following IM
succinylcholine, onset of neuromuscular blockade takes
approximately 2 to 5 minutes; the response in patients who are
hypotensive or hypovolemic is unpredictable.
In the Proposed Approach to the management of
laryngospasm first of all is to think of:
Airway irritation/obstruction
Blood/secretions
Light anaesthesia
Regurgitation
The main aim is to rapidly
oxygenate child!
100% oxygen (warm, humidified,
oxygen enriched air mixture in neonates)
Visualize and clear pharynx/airway
Jaw thrust with bilateral digital pressure behind
temporomandibular joint, oral/nasal airway
Deepen anaesthesia with propofol (20% induction dose)
Succinylcholine 0.5 mg/kg to relieve laryngospasm
(1.0-1.5 mg/kg i.v. or 4.0 mg/kg i.m. for intubation
Be aware of use in children < 2 years old!!!
Intubate and ventilate
Airway obstruction in the postoperative period
post-intubation croup
Laryngeal edema - in neonates and infants = inspiratory
stridor within 6 h of extubation (Subglottic edema of 1 mm in neonates
can reduce the laryngeal lumen by 35%)
- Supraglottic oedema
- Retroarytenoidal oedema
- Subglottic oedema
Associated risk factors
tight fitting tube
trauma at intubation
duration of intubation >1 h
coughing on the tube
change of head and neck position during surgery
Management of laryngeal edema
warm, humidified, oxygen enriched air mixture
nebulized epinephrine 1:1000 (0.5 ml kg−1 up to 5 ml)
dexamethasone 0.25 mg kg−1 followed
by 0.1 mg kg−1 six hourly for 24 h
reintubation with a smaller tube in severe cases
Conclusion
● Upper airway obstruction (UAO) is a life-threatening emergency that
requires prompt diagnosis and treatment
● Severe UAO can be surprisingly asymptomatic at rest if it develops
gradually. Sudden clinical deterioration is unpredictable
● Patients with possible UAO must never be sedated until the airway is
secured. Minimal sedation may precipitate acute respiratory failure
● Achievement of airway patency in total airway obstruction and
reestablishment of ventillatory airflow is the first and foremost goal of
the anaesthesiologists
Conclusion
● Critical care physicians must be aware that pharmacologic
interventions (epinephrine, steroids, and heliox) provide
temporary support but cannot significantly improve mechanical
UAO
● Bronchoscopy constitutes the most accurate diagnostic tool
and frequently provides the best way to correct UAO
● Cricothyroidotomy is the surgical intervention of choice to
reestablish airflow when medical interventions have failed
Conclusion
If the anaesthesiologist is competent in the
full range of airway access procedures and
when appropriately management is
performed, the possibility of incidence and
consequences of acute airway obstruction in
children will be very low
Thank you