Q. A 30-year-old male is brought in by an ambulance to the emergency department after a motor vehicle accident. He complains of sudden onset stabbing chest pain on the left side, tachypnea, and shortness of breath. The patient states that the pain worsens on respiration. His blood pressure is 85/55 mmHg, heart rate 145/min, and respirations are 24/min. Physical examination shows a jugular venous pressure of 3 cm and bluish discoloration of the skin. On chest auscultation, diminished lung sounds are audible on the left side of the chest. On percussion, hyper-resonance is noted on the left side of the chest. Chest x-ray revealed a mediastinal shift towards the right. What is the most likely diagnosis?