Chest tube insertion for pneumothorax is best inserted at which location?

• A. 7th ICS MCL
• B. 7th ICS MAL
• C. 2nd ICS MAL
• D. 2nd ICS MCL

Answer: (D)

In an unstable patient with a tension pneumothorax, the priority is rapid relief of intrathoracic pressure. The quickest way to achieve that is needle thoracostomy in the second intercostal space at the midclavicular line, inserting just above the upper border of the rib to reach the pleural space. This apex location allows air to escape immediately and improves hemodynamics. Once the patient is stabilized, a chest tube is placed for definitive management, typically in the fourth or fifth intercostal space at the midaxillary line to continuously evacuate air and re-expand the lung. The second intercostal space at the midclavicular line is chosen for emergent decompression because it provides fastest access to relieve the emergency, whereas other sites are slower or better suited for definitive drainage rather than immediate relief.