A patient with a stab wound to the right lower chest is semiconscious, has labored breathing, collapsed jugular veins, and absent breath sounds on the right side. Which injury is most likely?

• A. Pneumothorax
• B. Hemothorax
• C. Ruptured spleen
• D. Liver laceration

Answer: (B)

When a penetrating chest wound produces absent breath sounds on the affected side, along with signs of poor perfusion and labored breathing, the most likely injury is blood in the pleural space causing a hemothorax. The stab wound in the right lower chest allows blood to leak into the pleural cavity, which collapses the right lung and stops normal air entry on that side. The accumulating blood also reduces venous return to the heart, so the neck veins appear collapsed or flat, which fits the patient’s hypovolemic state and contributes to the breathing difficulty and altered mental status.

This pattern helps distinguish it from pneumothorax, where air in the pleural space can also blunt breath sounds but tends to cause distended neck veins (in a tension pneumothorax) and may produce hyperresonance on percussion and possible tracheal shift — features not described here. Abdominal injuries like a ruptured spleen or liver laceration would not typically explain unilateral chest findings such as absent breath sounds on the right side.