Clinical meaning
The upper airway (nasopharynx, oropharynx, larynx) warms, humidifies, and filters inspired air before it reaches the lower airways. Airway patency depends on intact neuromuscular tone, adequate mucociliary clearance, and absence of obstruction. Loss of consciousness, edema, secretions, or foreign bodies can compromise the airway at any level, leading to hypoxemia within minutes.
Exam relevance
Risk factors: - Altered level of consciousness (GCS ≤ 8) - Post-anesthesia/sedation recovery - Trauma to face, neck, or chest - Anaphylaxis - Burns involving the airway - Neuromuscular disorders (myasthenia gravis, Guillain-Barré) - Obesity with obstructive sleep apnea
Diagnostics: - Assess airway patency using look, listen, feel approach - Evaluate breath sounds bilaterally with auscultation - Monitor continuous pulse oximetry and capnography (EtCO2) - Assess work of breathing (accessory muscle use, retractions) - Evaluate cough effectiveness and ability to manage secretions - Perform modified Allen test before arterial puncture if ABG needed