Airway obstruction

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Airway obstruction
Classification and external resources
MeSH D000402

Airway obstruction is a blockage of respiration in the airway. It can be broadly classified into being either in the upper airway or lower airway.

Upper airway obstruction[edit]

Further information: Choking

Causes of upper airway obstruction, foreign body aspiration, blunt laryngotracheal trauma, penetrating laryngotracheal trauma, tonsillar hypertrophy, paralysis of the vocal cord or vocal fold, acute laryngotracheitis such as viral croup, bacterial tracheitis, epiglottitis, peritonsillar abscess, pertussis, retropharyngeal abscess, spasmodic croup.[1]

Lower airway obstruction[edit]

Further information: Obstructive lung disease

Lower airway obstruction is mainly caused by increased resistance in the bronchioles (usually from a decreased radius of the bronchioles) that reduces the amount of air inhaled in each breath and the oxygen that reaches the pulmonary arteries. It is different from airway restriction (which prevents air from diffusing into the pulmonary arteries because of some kind of blockage in the lungs). Diseases that cause lower airway obstruction are termed obstructive lung diseases.

Lower airway obstruction can be measured using spirometry. A decreased FEV1/FVC ratio (versus the normal of about 80%) is indicative of an airway obstruction, as the normal amount of air can no longer be exhaled in the first second of expiration. An airway restriction would not produce a reduced FEV1/FVC ratio, would produce a reduced vital capacity. The ventilation is therefore affected leading to a ventilation perfusion mismatch and hypoxia.

Consequences[edit]

Airway obstruction may cause obstructive pneumonitis or post-obstructive pneumonitis.

References[edit]

  1. ^ Respiratory Emergencies, section Acute Upper Airway Obstruction. From FP Essentials 368. January 2010 by American Academy of Family Physicians.

See also[edit]