What is the purpose of sealing a chest wound with a three-sided occlusive dressing?

• A. To keep the wound fully sealed to prevent air entry
• B. To prevent air from entering the chest entirely
• C. To allow air to escape and prevent tension pneumothorax
• D. To accelerate healing by moisture retention

Answer: (C)

When a chest wound, if it’s sealed too tightly, air can get trapped in the chest and build up pressure, potentially leading to a life-threatening tension pneumothorax. A three-sided occlusive dressing is used to create a vented seal: it covers the wound on three sides but leaves one edge open. This setup blocks air from entering the chest during inhalation while still allowing air to escape during exhalation, so pressure doesn’t build up. That’s why the purpose is to allow air to escape and prevent tension pneumothorax. It isn’t about keeping the wound fully sealed or accelerating healing by moisture retention, which aren’t the primary goals in this emergency technique.