Airway

An airway is the passage by which air enters the lungs and carbon dioxide exits. In humans it comprises the upper airway (the nasal and oral cavities, pharynx, and larynx) and the lower airway (the trachea, bronchi, bronchioles, and the distal alveolar units).

The airway conditions inspired air by warming, humidifying, and filtering it. The mucociliary escalator traps particles and transports mucus out of the lungs, while protective reflexes such as coughing and the epiglottis help prevent aspiration.

Airway management is essential in anesthesia, critical care, and emergency medicine. Common devices include oropharyngeal and nasopharyngeal airways, laryngoscope-guided endotracheal tubes, supraglottic airways, and, when indicated, emergency access such as cricothyrotomy.

Disorders affecting the airway include acute obstruction from foreign bodies or swelling, inflammatory conditions such as croup or epiglottitis, and chronic diseases like asthma or COPD that involve airway narrowing. Tumors, trauma, and infections can also impair airway patency. Signs of airway compromise may include stridor, wheeze, dyspnea, and the use of accessory muscles.

Assessment aims to determine patency and adequacy of ventilation. Management may require maneuvers to open the airway, suctioning, supplemental oxygen, and airway support with devices or procedures to secure ventilation when needed.