What is the purpose of applying a three-sided occlusive dressing over a penetrating chest wound?

• A. Prevent air entry while allowing air to escape
• B. Stop all air movement
• C. Promote air entry
• D. Keep dressing dry only

Answer: (A)

Controlling air movement through a penetrating chest wound is the point. By sealing three sides of the dressing and leaving one edge open, air cannot be drawn into the chest through the wound during inhalation, but air can escape if pressure builds during exhalation. This helps prevent a tension pneumothorax while still allowing the wound to vent. A fully sealed dressing could trap air and worsen pressure, and a dressing that promotes air entry would worsen the injury. Keeping the dressing dry matters, but the main purpose here is managing air flow through the wound.