A 58-year-old man with a 40-pack-year smoking history presents with progressive dyspnea and stridor over 3 weeks. Laryngoscopy reveals a large mass at the level of the vocal cords with 70% airway obstruction. The patient is scheduled for urgent airway management. After securing the airway with an endotracheal tube, the ENT team plans definitive surgical management. However, the patient develops subcutaneous emphysema and mild crepitus over the anterior neck 48 hours post-intubation. What is the most likely complication that has occurred, and what is the immediate management?