Direct airway damage can occur anywhere between the nasopharynx and the bronchi.
- Maxillofacial Injuries. In addition to soft tissue edema of the pharynx and peripharyngeal hematoma, blood or debris in the oropharynx may be responsible for partial or complete airway obstruction in the acute stage of these injuries.
- Serious airway compromise may develop within a few hours in up to 50% of patients with major penetrating facial injuries or multiple trauma as a result of progressive inflammation or edema resulting from liberal administration of fluids.
- Fracture-induced encroachment on the airway or limitation of mandibular movement, pain, and trismus may limit mouth opening. (Fentanyl in titrated doses of up to 2–4 µg/kg over a period of 10–20 minutes may produce an improvement in the patient's ability to open the mouth if mechanical limitation is not present.)
- Most patients with isolated facial injuries do not require emergency tracheal intubation. Surgery may be delayed for as long as 1 week with no adverse effect on the repair. Alternatively, tracheostomy may be indicated as an emergency procedure.
- Cervical Airway Injuries. Clinical signs such as air escape, hemoptysis, and coughing are present in almost all patients with penetrating injuries, facilitating the diagnosis. In contrast, the patient with major blunt laryngotracheal damage may asymptomatic or not recognized because suggestive signs and symptoms are missed in the initial evaluation (hoarseness, muffled voice, dyspnea, stridor, dysphagia)
- A CT scan of the neck provides valuable information and should be performed before any airway intervention in all stable patients.
- Laryngeal damage precludes cricothyroidotomy. Tracheostomy should be performed with extreme caution because up to 70% of patients with blunt laryngeal injuries may have an associated C-spine injury.
- Thoracic Airway Injuries. Blunt injury usually involves the posterior membranous portion of the trachea and the mainstem bronchi, usually within approximately 3 cm of the carina.
- In patients intubated without the suspicion of a tracheal injury, difficulty in obtaining a seal around the endotracheal tube or the presence on a chest radiograph of a large radiolucent area in the trachea corresponding to the cuff suggests a perforated airway.
- Anesthetics, and especially muscle relaxants, may produce irreversible obstruction, presumably because of relaxation of structures that maintain the airway patent in the awake patient. Airway loss may also occur during attempts at awake intubation.