Before placing a commercial chest seal on an open chest wound, what should the casualty do?

• A. Fully Exhale
• B. Inhale deeply
• C. Speak to describe pain
• D. Move around

Answer: (A)

The key idea is to prevent air from being sucked into the chest through the wound as you seal it. Have the casualty exhale fully before placing the chest seal. Exhaling lowers intrathoracic pressure, reducing the chance that air will be drawn into the chest when you apply the dressing. The chest seal is designed to be occlusive with a one-way mechanism to vent air if needed, but it should not be applied while air is being drawn into the wound. After the seal is in place, the casualty can breathe normally.

Inhaling deeply at that moment could push air into the chest through the wound, worsening a pneumothorax. Speaking or moving doesn’t address the risk and could complicate the situation.