What is the first-line imaging modality to rapidly assess suspected pneumothorax in a hemodynamically unstable patient?

• A. Chest radiography
• B. MRI
• C. CT scan
• D. Point-of-care ultrasound

Answer: (D)

In a hemodynamically unstable patient, the priority is a rapid, bedside assessment to detect pneumothorax and guide immediate action. Point-of-care ultrasound fits this need because it can be done right at the bedside within minutes, without moving the patient, and it remains highly sensitive for identifying pneumothorax even when the patient is supine.

During the exam, look for signs such as the absence of pleural sliding on the affected side, which suggests air between the visceral and parietal pleura. The presence of a lung point—the exact location where the collapsed lung meets the chest wall—is highly specific for pneumothorax. M-mode can show the barcode or stratosphere sign when there’s no lung movement. These ultrasound findings allow rapid confirmation and immediate management decisions, such as needle decompression or chest tube placement if a tension pneumothorax is suspected.

Chest radiography can miss posterior or small pneumothoraces in unstable patients and takes longer, while CT is very accurate but impractical and risky to transport a hemodynamically unstable patient. MRI isn’t suitable for acute, unstable trauma.

So, the fastest and most practical first-line imaging in this scenario is bedside ultrasound.