What is an initial treatment measure for subcutaneous emphysema?

• A. Place diver on 100% O2
• B. Immediate recompression
• C. Perform chest X-ray first
• D. Administer diuretics

Answer: (A)

Speeding the resorption of trapped gas with high-concentration oxygen is the key idea. Subcutaneous emphysema happens when air leaks into the tissues, and in divers that air often contains nitrogen. Breathing 100% oxygen lowers the nitrogen partial pressure in the blood and tissues, creating a diffusion gradient that drives nitrogen out of the subcutaneous air into the bloodstream to be exhaled. This accelerates the resolution of the emphysema and supports better overall gas exchange.

Immediate recompression is reserved for decompression illness or arterial gas embolism, not for isolated subcutaneous emphysema. Chest imaging can help diagnose underlying injuries, but waiting for imaging before giving oxygen can delay treatment. Diuretics don’t address trapped gas and aren’t indicated.