Upper Airway Obstruction: Causes, Assessment and Emergency Management
Upper airway obstruction is partial or complete blockage from the nose and pharynx to the larynx and extrathoracic trachea. It can deteriorate within minutes; treatment is guided by the patient's physiology and likely cause, not by waiting for a definitive test.
Inability to speak or cough, silent airflow, exhaustion, altered consciousness, cyanosis, severe recession, rapidly worsening stridor or falling oxygen saturation indicate critical obstruction. Call for senior airway help immediately and prepare a rescue plan.
Learning objectives
- Classify causes by anatomical level, age and speed of onset.
- Recognise stridor and signs of impending respiratory failure.
- Perform an ABCDE assessment without worsening obstruction.
- Outline cause-specific treatment and escalation to a definitive airway.
Functional anatomy and sound
| Finding | Likely level | Examples |
|---|---|---|
| Snoring/stertor | Nose, nasopharynx or oropharynx | Secretions, reduced tone, adenotonsillar enlargement |
| Inspiratory stridor | Supraglottis or glottis | Croup, epiglottitis, laryngeal oedema, foreign body |
| Biphasic stridor | Glottis, subglottis or fixed central airway lesion | Subglottic stenosis, bilateral vocal-fold immobility |
| Expiratory wheeze | Intrathoracic lower airway more likely | Asthma, bronchiolitis; a central foreign body can produce mixed signs |
Causes
Food, toys, blood, facial injury, laryngeal fracture, burns or post-intubation swelling.
Viral croup, epiglottitis, bacterial tracheitis, tonsillitis, peritonsillar or retropharyngeal abscess.
Anaphylaxis, angio-oedema, drug reaction, inhalational or caustic injury.
Tumour, goitre, congenital stenosis, laryngomalacia, bilateral vocal-fold paralysis or sleep-related collapse.
Children have a narrower airway and can deteriorate rapidly with small increases in mucosal oedema. In adults, consider tumour, deep-neck infection, anaphylaxis, trauma and foreign body.
Clinical assessment
Rapid look-and-listen assessment
- Position, ability to speak, cry or feed, voice quality and presence of drooling.
- Respiratory rate, effort, chest movement, recession and accessory-muscle use.
- Stridor timing and loudness; a quieter stridor with worsening effort may mean falling airflow, not improvement.
- Air entry, cough strength, oxygen saturation, heart rate and mental state.
Keep a child with the caregiver in the position of comfort. Do not force the patient supine or perform an unnecessary throat examination when epiglottitis or critical obstruction is suspected. Agitation can precipitate complete obstruction.
ABCDE approach
- Airway: call for help, open with simple manoeuvres, suction visible secretions and remove only a clearly visible object. Use jaw thrust if cervical injury is possible.
- Breathing: give high-concentration oxygen when tolerated, monitor continuously and assist ventilation with bag-mask technique if inadequate.
- Circulation: obtain IV or intraosseous access without delaying airway care; treat shock.
- Disability: falling consciousness, bradycardia or exhaustion are late signs.
- Exposure: look for urticaria, facial swelling, burns, trauma, neck swelling and fever.
Important differential features
| Condition | Clues | Immediate priorities |
|---|---|---|
| Foreign body | Sudden choking, cough, unilateral findings or witnessed ingestion | Age-appropriate choking manoeuvres for severe obstruction; bronchoscopy/ENT removal. |
| Croup | Barking cough, hoarseness, inspiratory stridor, viral prodrome | Minimise distress; corticosteroid and nebulised adrenaline for moderate/severe disease per protocol. |
| Epiglottitis/deep infection | Fever, toxic appearance, severe sore throat, drooling, muffled voice, tripod position | Do not examine throat forcibly; controlled airway with anaesthesia/ENT and IV antimicrobials. |
| Anaphylaxis | Rapid airway/breathing/circulatory features, often with skin or gastrointestinal symptoms | Immediate intramuscular adrenaline according to current protocol; airway support and fluids. |
| Angio-oedema | Lip, tongue or laryngeal swelling; allergic, hereditary or drug-related | Early expert airway plan plus cause-specific treatment. |
| Trauma/burn | Neck injury, soot, facial burns, hoarseness or expanding haematoma | Early controlled airway before oedema progresses; trauma management. |
Investigations
Do not delay airway stabilisation for tests. A clinically critical obstruction may require treatment in theatre or the resuscitation area before imaging.
- Continuous pulse oximetry and ECG; blood gas when it will change management and can be obtained safely.
- Flexible nasolaryngoscopy by an experienced clinician in a controlled setting for stable patients.
- Neck/chest radiographs for selected foreign body, swelling or tracheal disease; normal films do not exclude obstruction.
- CT neck/chest with contrast for stable patients with suspected deep-neck infection, mass or extrinsic compression.
- Full blood count, cultures and inflammatory markers when infection is suspected, without delaying antibiotics in severe disease.
Emergency management
Initial measures
- Activate the difficult-airway team and assign roles, equipment and backup plans.
- Allow spontaneous breathing and the position of comfort when positive-pressure ventilation or sedation could worsen dynamic obstruction.
- Use suction, basic airway manoeuvres and appropriate airway adjuncts when tolerated.
- Pre-oxygenate and prepare appropriately sized tubes, video/flexible devices and front-of-neck access equipment.
Cause-specific treatment
- Severe choking: follow current age-appropriate basic life-support manoeuvres; begin CPR if unresponsive and inspect the mouth only for a visible removable object. Never perform blind finger sweeps.
- Anaphylaxis: give intramuscular adrenaline promptly according to current weight/age protocol; repeat as directed while treating shock and arranging airway support.
- Croup: administer corticosteroid; use nebulised adrenaline for significant stridor/distress and observe for recurrence according to protocol.
- Bacterial infection: secure the airway when needed, obtain cultures if safe, then give appropriate IV antibiotics and drain an abscess when indicated.
- Oedema or burns: anticipate progression and intubate early when warning signs are present.
Definitive airway
Tracheal intubation should be performed by the most experienced available clinician with anaesthetic and ENT/surgical backup. A smaller tube may be required. If oxygenation cannot be maintained and intubation fails, proceed immediately to the locally recommended emergency front-of-neck airway. In young children, the rescue technique differs from adults and requires paediatric expertise.
Complications
- Hypoxic brain injury, cardiac arrest and death.
- Aspiration, negative-pressure pulmonary oedema and pneumonia.
- Airway trauma, bleeding, pneumothorax or surgical-airway complications.
- Post-obstruction oedema, recurrent obstruction and subglottic stenosis.
Review the anatomy of the larynx, anatomy of the pharynx, congenital throat stenosis and laryngitis.
Key examination points
- Stridor is a sign, not a diagnosis.
- A silent or exhausted patient may have more severe obstruction than a noisy patient.
- Airway intervention must not wait for imaging.
- Keep a distressed child calm and avoid unsafe throat examination.
- Always plan intubation, rescue oxygenation and surgical backup together.
References and further reading
- WHO: Basic Emergency Care.
- NCBI Bookshelf: Upper Airway Obstruction.
- Resuscitation Council UK: Resuscitation Guidelines.
For education only. Apply current Uganda Clinical Guidelines, age-appropriate resuscitation algorithms, local protocols and senior specialist advice.
