What is the purpose of a chest seal on an open chest wound?

• A. To apply a decorative label
• B. To seal the wound and prevent air from entering the chest cavity, reducing the risk of tension pneumothorax
• C. To cleanse the wound
• D. To immobilize the chest

Answer: (B)

Open chest wounds create a direct path for air to move into the chest cavity with each breath. A chest seal covers the wound with an occlusive dressing that blocks air from entering the pleural space, which helps prevent a tension pneumothorax. Many chest seals are designed to be occlusive yet allow air to escape during exhalation (one-way behavior), so pressure inside the chest doesn’t build up and compromise breathing and circulation. This is the purpose: to keep the lung expanded and reduce the risk of life-threatening pressure from within the chest. It’s not about labeling, cleaning, or immobilizing—the seal’s job is specifically to prevent air entry and limit pressure changes in the chest.