Acute upper airway obstruction

Acute upper airway obstruction can be caused by foreign body aspiration, viral or bacterial infections (croup, epiglottitis, tracheitis), anaphylaxis, burns or trauma.
Initially stable and partial obstruction may worsen and develop into a life-threatening emergency, especially in young children.

Clinical features

Clinical signs of the severity of obstruction:



Danger signs


  • Respiratory distress followed by cardiac arrest


Imminent complete

  • Severe respiratory distress with cyanosis or SpO2 < 90%
  • Agitation or lethargy
  • Tachycardia, capillary refill time > 3 seconds


  • Stridor (abnormal high pitched sound on inspiration) at rest
  • Severe respiratory distress:
    • Severe intercostal and subcostal retractions
    • Nasal flaring
    • Substernal retractions (inward movement of the breastbone during inspiration)
    • Severe tachypnoea


  • Stridor with agitation
  • Moderate respiratory distress:
    • Mild intercostal and subcostal retractions
    • Moderate tachypnoea



  • Cough, hoarse voice, no respiratory distress

Management in all cases

– Examine children in the position in which they are the most comfortable.
– Evaluate the severity of the obstruction according to the table above.
– Monitor SpO2, except in mild obstruction.
– Administer oxygen continuously:
• to maintain the SpO2 between 94 and 98% if it is ≤ 90%1 or if the patient has cyanosis or respiratory distress;
• if pulse oxymeter is not available: at least 5 litres/minute or to relieve the hypoxia and improve respiration.
– Hospitalize (except if obstruction is mild), in intensive care if danger signs.
– Monitor mental status, heart and respiratory rate, SpO2 and severity of obstruction.
– Maintain adequate hydration by mouth if possible, by IV if patient unable to drink.

Management of foreign body aspiration

Acute airway obstruction (the foreign body either completely obstructs the pharynx or acts as a valve on the laryngeal inlet), no warning signs, most frequently in a child 6 months-5 years playing with a small object or eating. Conscience is initially maintained.

Perform maneuvers to relieve obstruction only if the patient cannot speak or cough or emit any sound:
– Children over 1 year and adults:
Heimlich manoeuvre: stand behind the patient. Place a closed fist in the pit of the stomach, above the navel and below the ribs. Place the other hand over fist and press hard into the abdomen with a quick, upward thrust. Perform one to five abdominal thrusts in order to compress the lungs from the below and dislodge the foreign body.
– Children under 1 year:
Place the infant face down across the forearm (resting the forearm on the leg) and support the infant’s head with the hand. With the heel of the other hand, perform one to five slaps on the back, between shoulder plates.
If unsuccessful, turn the infant on their back. Perform five forceful sternal compressions as in cardiopulmonary resuscitation: use 2 or 3 fingers in the center of the chest just below the nipples. Press down approximately one-third the depth of the chest (about 3 to 4 cm).

Repeat until the foreign body is expelled and the patient resumes spontaneous breathing (coughing, crying, talking). If the patient loses consciousness ventilate and perform cardiopulmonary rescucitation. Tracheostomy if unable to ventilate.

Differential diagnosis and management of airway obstructions of infectious origin




Timing of symptoms

Viral croup

Stridor, cough and moderate respiratory difficulty

Prefers to sit



Stridor, high fever and severe respiratory distress

Prefers to sit, drooling (cannot swallow their own saliva)


Bacterial tracheitis

Stridor, fever, purulent secretions and severe respiratory distress

Prefers to lie flat


Retropharyngeal or tonsillar abscess

Fever, sore throat and painful swallowing, earache, trismus and hot potato voice

Prefers to sit, drooling


– Croup, epiglottitis, and tracheitis: see Other upper respiratory tract infections.
– Abscess: refer for surgical drainage.

Management of other causes

– Anaphylactic reaction (angioedema): see Anaphylactic shock (Chapter 1)
– Burns to the face or neck, smoke inhalation with airway oedema: see Burns (Chapter 10).

Ref Notes
1 If possible it is better to treat all patients with a SpO2 < 95% with oxygen.