Which finding is associated with obstructive shock?

• A. Asymmetric or absent unilateral breath sounds
• B. JVD
• C. Clear lungs
• D. Normal respiration

Answer: (A)

Obstructive shock happens when something physically blocks blood flow, most notably a tension pneumothorax in the prehospital setting. In a tension pneumothorax, air builds up in one side of the chest, the lung on that side collapses, and the mediastinum shifts, which compresses the heart and great vessels and greatly impedes venous return. That drop in preload and cardiac output leads to shock. The clearest clue is asymmetric or absent breath sounds on one side, which points to a pneumothorax causing the obstruction. JVD can occur with obstructive states but isn’t as specific, and lungs being clear or respiration appearing normal would argue against a pneumothorax and thus obstructive shock in this context.