Final answer:
For a patient with subcutaneous emphysema threatening airway patency, the correct intervention is endotracheal intubation to maintain an open and protected airway.
Step-by-step explanation:
A patient with thoracic trauma is admitted to the ICU and presents with chest and neck swelling along with a crackling sensation upon palpation, indicating the presence of subcutaneous emphysema. If this condition becomes severe, compromising airway patency, the most immediate and life-saving intervention would be to secure the airway. The preferred method for securing the airway in an acute setting, especially if there is a risk of airway obstruction, is through endotracheal intubation.
Placement of an endotracheal tube allows healthcare providers to maintain an open airway directly into the lungs and protect the airway from the oropharynx. This is particularly important during general anesthesia or if the patient's own muscles of respiration are compromised. Other options such as a chest tube, tracheostomy, or feeding tube may be considered for other reasons or in a different context, but for immediate airway protection, endotracheal intubation is indicated.