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 pointsCauses 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*

The major causes are: Viral croup (80%)** Epiglotitis (5%) Foreign body

aspiration

Failure to manage the airway is the leading cause of preventable

pediatric deaths

* 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

Infants and children decompensate more quickly compared to

adults

Infections

Thermal injury

Congenital anomalies Post-

extubation laryngospasm

Depressed conscious level

Trauma

Rapidlyprogressive

Airwayobstruction

Airway foreign body

Life-threatening emergency

*Morton NS. Large airway obstruction in children: causes, assessment and management. Update Anaesthesia 2004; 18 (article 13):1

Laryngospasm after tracheal extubation –major of UAO after surgery

Important causes of airway obstruction in children

Anaphylactoid reactions

Signs of airway obstruction in children

- 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

conscious patient unconscious or sedated patient

- 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

TachypneaParadoxical 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 respirationauto CPAPPosition: Infants may assume an opisthotonic position; the

"tripod" or sniffing position is seen in the older child

Signs of increased work of breathing

Inspiratory stridor Expiratory stridor

Stridor

The magnitude or severity of stridor does not correlate with the severity of obstruction

airway compromise at the supraglotic or laryngeal level intrathoracic obstruction

Signs of ineffective breathing and respiratory failure:

CyanosisAltered consciousnessBradypnea, apneic spelssSilent chest in spite of vigorous effort

Compleet airway obstruction

Choking, absent breath sounds and aphonia This rapidly progresses to cyanosis, bardycardia and cardiac arrest

Post-extubation laryngospasm, angiooedema and

anaphylactoid reactions

Airway obstruction with foreign bodyForeign-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

• Children with a history of choking and subsequent symptoms must be referred to immediate bronchoscopy!

Airway obstruction with foreign body

• Oropharyngeal foreign bodies :mouth breathing

• Nasal foreign bodies unilateral rhinorrhea and stinking breath

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

*Schmidt H., Manegold BC. Foreign body aspiration in children. Surg Endosc 2000; 14:644-8

*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

“Circulus viciosus”BLS maneuvers(Heimlich, Guidel )

direct laryngoscopy

Complications1. Mild oedema of the respiratory mucosa

2. Tracheobronchitis3. granulation tissue

Most patients can be discharged within 24 h

Magill forceps or suction

flexible bronchoscopy

short course of corticosteroids

Repeat bronchoscopy rigid 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

cords are sprayed with local anaesthetic

gentle assistance with inhalational technique

rigid bronchoscope with a ventilating side arm is inserted, facilitated by laryngoscopyhigher FiO2

DexamethadoneThe 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

Sevoflurane might be choice, but its use has some controversy, because lower potency of sevoflurane may not permit intubation

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

volatile anaesthetics

The Jackson-Rees modification of Ayer,s “T piece” circuit- CPAP

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

intubation is difficult or impossible

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

flexible fiberoptic bronchoscopy

As the depth of anaesthesia increases, the child may be gradually lowered to the

supine position

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 placeThe 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

Usually affects children from 6 months to 4 years of age, with a peak incidence at 2 years of age

Endoscopic view of subglottic oedemain viral croup

Radiological presentation of subglottic oedema in viral croup (left) compared with

a normal trachea (right)

acute clinical syndrome of hoarse voice, barking cough and stridor

There is some controversy regarding treatment with epinephrine

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).

Epiglotitis

Conversely, epinephrine is not effective in the treatment of epiglottitis and may be deleterious.

Controversy! To look or not to look

Airway burns

Exposure in an enclosed spaceDecreased level of consciousness, confusion

Soot in mouth, nares

Swelling, ulceration of oral mucosa or tongue

Suspect for inhalation injury

Carbonaceous sputum

Dyspnoea

Hoarseness

Stridor, wheeze, crepitations

Increased work of breathingOxygen saturations <94% in air

Caboxyhaemoglobin >5% on co-oximetry

Heat produces an immediate injury to the airway mucosa edema

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 patencyProtect against aspirationPulmonary toilet to decrease mucous plugging and infection risks

Need for positive-pressureWhen in doubt, it is safer to intubate!

TRAUMATIC LESIONS

Damage from endotracheal intubation andtracheotomy

Even the dictum that ‘cuffed endotracheal tubes should not be used inchildren under the age of 8 years’ can no longer be maintained

since the development of high-volume, low-pressure cuffs*

*Newth CJL, Rachman B, Patel N, Hammer J. The use of cuffed versusuncuffed endotracheal tubes in pediatric intensive care. J Pediatr 2004; in press

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

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 - life-threatening complication aspiration, airway obstruction

local irritation by blood or saliva light planes of anaesthesia Child undisturbed - in the lateral recovery position

Tracheal extubation

HypoventilationHypoxemiaHypercarbiaCardiac dysrhythmiasCardiac arrest

deep anesthesia

awake

Concern:light plane of anesthesia!

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 forregurgitation/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 - Awake- Following commands- Breathing spontaneuosly- Wheel oxigenated

- Not excessively hyperbaric- (PaCo2 50 mmHg

- Fully recovered from MR- Sustained head lift- Strong hand grip- Strong tongue protrusion

- Hypoxic (O2 saturation < 90 mmHg)

- Excessively hyperbaric(Pa CO2 >50mm Hg

- Hypothermic (< 34 C)- NMB present

Partial laryngospasm complete laryngospasm

inspiratory stridor

Increased airway problems

children with a history of a recent upper respiratory tract infection former premature infants

children with chronic, obstructive sleep apnea

absence of air movementTracheal tug and paradoxical (“see-saw”) movement of the abdomen

If necessary a dose of succinylcholine followed by tracheal re-intubation (in children older than 2 years!!!)

mild biphasic snoring-noisy breathing

Managament of laryngospasm

jaw thrust maneuver, neck extension and mouth opening

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

 Of particular concern have been the instances of life-threatening 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. 

Airway irritation/obstruction

Blood/secretions

Light anaesthesia

Regurgitation

In the Proposed Approach to the management of laryngospasm first of all is to think of:

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

Associated risk factors

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

tight fitting tubetrauma at intubationduration of intubation >1 hcoughing on the tubechange 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

● 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

Conclusion

Thank you