Tension Pneumothorax — Needle Decompression

A 24-year-old tall, thin male smoker presents to the emergency department in extremis with severe right-sided pleuritic chest pain, breathlessness, BP 80/50 mmHg, HR 140/min, RR 36/min, SpO₂ 84% on 15 L oxygen, cool clammy peripheries, bulging neck veins, tracheal deviation to the left, absent breath sounds over the right hemithorax with hyperresonant percussion, and reduced chest expansion on the right. He has not been intubated. A portable erect chest X-ray is obtained. The structure marked **A** in the diagram—the hyperlucent hemithorax with absent lung markings—is a pathognomonic radiological finding in this clinical scenario. Which of the following is the IMMEDIATE life-saving intervention required in this patient?