A wound that is considered a sucking chest wound is approximately what size relative to the trachea?

• A. 2/3 the size of the trachea
• B. 1/2 the size of the trachea
• C. 1/4 the size of the trachea
• D. Equal to the size of the trachea

Answer: (A)

The key idea here is estimating how large a chest wound must be to be considered a sucking chest wound. In field practice, a wound that communicates with the pleural space and is large enough to cause a noticeable air leak is typically described as about two-thirds the width of the trachea. That size is large enough to allow significant air movement with breathing, which is what creates the sucking chest wound sign and drives the need for rapid occlusive management.

So, a wound roughly two-thirds the trachea’s diameter best fits the definition, because it represents a sizable opening without being as large as the trachea itself. Smaller options, like about half or a quarter the trachea, would usually be considered less likely to produce the classic sucking sign, and a wound equal to the trachea would imply an unusually large opening.

Therefore, two-thirds the size of the trachea is the best choice.