Upper Airway Obstruction

Excerpt

The upper airway consists of the nasal cavities, oral cavity, pharynx, and larynx. The pharynx is further subdivided into the nasopharynx, oropharynx, and hypopharynx. The larynx is divided into three regions, dependent on their relationship to the vocal cords (glottis). These areas are the supraglottis, glottis, and subglottis. The supraglottis consists of the epiglottis, the arytenoids, the aryepiglottic folds, the false cords, and the ventricles. The subglottis is the subregion just below the free edge of the vocal cords to the inferior margin of the cricoid. The narrowest part of an adult airway is the glottis. The narrowest part of a pediatric airway is the cricoid. Upper airway obstruction varies from narrowing to partial or complete occlusion of any of these anatomic structures, potentially leading to a compromise in ventilation. Given the urgency related to this issue, it is crucial that healthcare professionals fully understand and appreciate the signs and symptoms that indicate upper airway obstruction.

When forming a differential diagnosis for upper airway obstruction, it is important to determine the level at which the obstruction is occurring. A vital clinical sign is noisy breathing, which can be described as 'stertor' or 'stridor'. ‘Stertor’ is noisy breathing which occurs above the larynx. ‘Stridor’ is noisy breathing that occurs at the level of the larynx or below. Stridor can be further subdivided as inspiratory (level of the supraglottis), expiratory (level of the glottis), and biphasic (level of the subglottis or trachea).

Upper airway obstruction can be partial or complete. A partial obstruction can be chronic or acute, therefore it is crucial to take a good history and perform an efficient and comprehensive exam to determine the etiology of the obstruction and therefore the urgency of subsequent management. Left untreated, upper airway obstruction can have significant long-term or fatal effects.