Tension pneumothorax results in all except?
**Core Concept**
Tension pneumothorax is a life-threatening condition characterized by the accumulation of air in the pleural space, which cannot escape, leading to increased intrathoracic pressure on the affected side. This condition can compress the mediastinum, causing a shift in the mediastinal structures and compromising venous return to the heart.
**Why the Correct Answer is Right**
Tension pneumothorax results in **mediastinal shift** towards the affected side, which can compress the superior and inferior vena cava, and also compromise the cardiac output. The increased intrathoracic pressure can also cause **decreased lung expansion** on the affected side, leading to hypoxia and respiratory distress.
**Why Each Wrong Option is Incorrect**
**Option A:** This option might seem plausible, but tension pneumothorax does not result in decreased intrathoracic pressure. Instead, it leads to increased intrathoracic pressure on the affected side.
**Option B:** While tension pneumothorax can cause decreased lung expansion, this is not the only effect. The correct answer should be a distinct consequence that is not a result of tension pneumothorax.
**Option D:** This option might be true, but it is not the only consequence of tension pneumothorax. The correct answer should be a consequence that is not associated with tension pneumothorax.
**Clinical Pearl / High-Yield Fact**
In a patient with suspected tension pneumothorax, a **needle thoracostomy** should be performed immediately to relieve the pressure and stabilize the patient before definitive treatment.
**Correct Answer: C.**