Airway obstruction is a blockage of the airways, which impedes air flow and effective respiration.
- Upper airway obstruction (UAO):
- Nasopharynx, larynx, and trachea
- Central airway obstruction (CAO):
- Trachea and mainstem bronchi
- Lower airway obstruction (LAO):
- Distal to mainstem bronchi
- Involves small airways
- Usually a manifestation of chronic disease
- Exact incidence is unknown.
- Occurs in 20%–30% of patients with lung cancer
Upper airway obstruction and CAO (large airway obstruction):
- Lung cancer most common
- Benign masses (papillomas)
- Aspiration of foreign body
- Mucous plug
- Angioedema (tongue swelling)
- Obstructive sleep apnea (OSA)
- Tracheal strictures/stenosis
- Airway hematomas (trauma)
- Extrinsic compressions (e.g., vascular rings, thyroid tumors)
Lower airway obstruction (small airway obstruction):
- Chronic obstructive pulmonary disease (COPD)
- Post-infective bronchial hyperreactivity
- Bronchiectasis and cystic fibrosis
- Allergic bronchopulmonary aspergillosis
- Endobronchial tuberculosis
- Extrinsic or intrinsic compression due to tumors
- Endobronchial granulation tissue or calcifications
- Thinning or collapse of the airway wall due to tracheomalacia
- Airway edema due to infection, inflammation, or bleeding
Chronic and subacute
- Minor obstruction is often asymptomatic initially.
- Can be caused by a mass, a stricture, or external compression
- Can be exacerbated by exertion, increased ventilatory demands (e.g., pneumonia), or progressive obstruction; and then become acute
- Precipitating events:
- Foreign body aspiration
- Mucous plug
- Laryngotracheal trauma
- Smoke inhalation
- Pediatric infections:
- Tonsillar or retropharyngeal abscess
- Acute exacerbation of mild chronic obstruction in the setting of swelling, bleeding, or increased secretions
Chronic and subacute
- Symptoms are non-specific:
- Chest pain
- Frequently misdiagnosed as asthma/COPD
- Diagnostic clues:
- Positional symptoms rather than diurnal (day vs. evening)
- Inspiratory wheeze (stridor)
- History of intubation or tracheal disease (tracheal stenosis)
- Acute onset tachypnea
- Inspiratory stridor
- Increased respiratory effort: suprasternal retractions, nasal flaring, grunting
- Gagging, gasping
- Obtunded mental status
History can be obtained from a responsive patient not in extremis.
- Does the patient have a history of:
- Respiratory disease
- Lung or head/neck cancer
- Foreign body aspiration
- Previous intubation/tracheostomy
- Neck surgery
- Pulse oximetry < 90%
- Facial/neck swelling
- Signs of respiratory distress (tachypnea, nasal flaring, gasping, use of accessory muscles)
- Direct inspection of the airways:
- Visual inspection (angioedema, foreign body)
- Should only be performed after airway stabilization
- Chest X-ray:
- Tracheal deviation
- Mediastinal shift
- Endobronchial luminal defect
- Neck X-ray:
- Thumbprint sign for epiglottitis
- Chest computed tomography (CT):
- More detailed imaging than X-ray
- Magnetic resonance imaging (MRI):
- For vascular pathology
- Soft tissue tumors (e.g., sarcomas)
Pulmonary function test (PFT)
For chronic/subacute symptoms in the setting of suspected obstruction:
- Minimal variability in peak flow/spirometry
- Characteristic “squared-off” flow-volume loop
- Fall in peak expiratory flow rate (PEFR) relatively greater than fall in forced expiratory volume in 1 second (FEV1)
- If a foreign body is suspected, abdominal thrusts (Heimlich maneuver) or back slaps (for infants) should be performed for responsive patients.
- Cardiopulmonary resuscitation is initiated for unresponsive patients.
- The goal of initial management:
- Provide adequate oxygenation
- Secure airway
- The initial step is bag-mask ventilation.
- Maneuvers to help open the airway:
- Head tilt-chin lift (if no cervical spine trauma is suspected)
- Jaw-thrust (allows airway opening without disturbing the cervical spine)
- Endotracheal intubation is the definitive airway management.
- If intubation cannot be accomplished:
- A laryngeal mask can be inserted if obstruction is from a swollen tongue.
- Emergent cricothyroidotomy or tracheostomy
- Rigid bronchoscopy and retrograde intubation may be needed in case of bronchial obstruction.
Not immediately life-threatening obstruction
- History, laboratory, and imaging evaluations can be obtained.
- Initial management:
- Sit the patient up.
- High-flow oxygen or heliox (a mixture of oxygen and helium) via a mask
- Intravenous high-dose corticosteroids (reduce edema around the obstruction)
- Nebulized salbutamol and adrenaline
- Intravenous fluid replacement
- Definitive management depends on the underlying cause.
- Chronic obstructive pulmonary disease: chronic obstructive inflammation of the small airways and changes in the lung parenchyma and pulmonary vasculature. Patients usually present with dyspnea and chronic cough. COPD is a progressive condition with acute flares. Management includes smoking cessation, pulmonary rehabilitation, and pharmacotherapy.
- Asthma: chronic inflammatory respiratory condition characterized by bronchial hyperresponsiveness and airflow obstruction. Patients typically present with wheezing, cough, and dyspnea. Diagnosis is confirmed with a PFT showing a reversible obstructive pattern. Treatment, based on symptom severity, includes bronchodilators and inhaled corticosteroids for control of inflammation.
- Aboussouan, L. S., & Stoller, J. K. (1994). Diagnosis and management of upper airway obstruction. Clinics in chest medicine, 15(1), 35–53. https://pubmed.ncbi.nlm.nih.gov/8200192/
- Herth F. JF. (2020). Clinical presentation, diagnostic evaluation, and management of central airway obstruction in adults. Retrieved 25 January 2021, from https://www.uptodate.com/contents/clinical-presentation-diagnostic-evaluation-and-management-of-central-airway-obstruction-in-adults
- Loftis L.L. (2019). Emergency evaluation of acute upper airway obstruction in children. Retrieved 25 January 2021, from https://www.uptodate.com/contents/emergency-evaluation-of-acute-upper-airway-obstruction-in-children
- Wittels K. (2019). Basic airway management in adults. Retrieved 26 January 2021, from https://www.uptodate.com/contents/basic-airway-management-in-adults