In a patient who is decompensating quickly from a pneumothorax, what immediate intervention is recommended?

• A. Oxygen
• B. Small-bore catheter
• C. 14-16 G needle decompression
• D. Chest tube attached to water seal

Answer: (C)

The immediate issue in a rapidly decompensating pneumothorax is a life-threatening tension physiology, where trapped air under pressure collapses the lung and impairs venous return to the heart. The fastest, lifesaving move is to decompress the chest with a large-bore needle (about 14–16 gauge) inserted into the chest—classically the second intercostal space at the midclavicular line—to vent the trapped air and relieve the pressure. This immediate relief helps restore circulation and breathing, buying time to place a definitive chest tube for ongoing drainage and lung re-expansion. Oxygen is important support, but it doesn’t resolve the mechanical problem right away. A small-bore catheter can be used in stable cases but may be too slow for a rapidly decompensating tension pneumothorax, and a chest tube with a water seal is essential but comes after the immediate decompression to quickly relieve the life-threatening pressure.