A 28-year-old woman is brought to the trauma bay after a stab wound to the left chest (5th intercostal space, midaxillary line). On arrival, BP 92/58 mmHg, HR 128/min, RR 26/min, JVD present, breath sounds decreased on the left. Chest X-ray shows a large left-sided hemothorax with mediastinal shift. The patient is alert and responding to commands. After 2 units of O-negative blood initiated, what is the most appropriate next step?