Are Chest Radiographs or Ultrasound More Accurate in Predicting a Pneumothorax or Need for a Thoracostomy Tube in Trauma Patients?

BACKGROUND: Historically, chest radiographs (CXR) have been used to quickly diagnose pneumothorax (PTX) and hemothorax in trauma patients. Over the last 2 decades, chest ultrasound (CUS) as part of Extended Focused Assessment with Sonography in Trauma (eFAST) has also become accepted as a modality for the early diagnosis of PTX in trauma patients.

METHODS: We queried our institution's trauma databases for all trauma team activations from 2021 for patients with eFAST results. Demographics, injury variables, and the following were collected: initial eFAST CUS, CXR, computed tomography (CT) scan, and thoracostomy tube procedure notes. We then compared PTX detection rates on initial CXR and CUS to those on thoracic CT scans.

RESULTS: 580 patients were included in the analysis after excluding patients without a chest CT scan within 2 hours of arrival. Extended Focused Assessment with Sonography in Trauma was 68.4% sensitive and 87.5% specific for detecting a moderate-to-large PTX on chest CT, while CXR was 23.5% sensitive and 86.3% specific. Extended Focused Assessment with Sonography in Trauma was 69.8% sensitive for predicting the need for tube thoracostomy, while CXR was 40.0% sensitive.

DISCUSSION: At our institution, eFAST CUS was superior to CXR for diagnosing the presence of a PTX and predicting the need for a thoracostomy tube. However, neither test is accurate enough to diagnose a PTX nor predict if the patient will require a thoracostomy tube. Based on the specificity of both tests, a negative CXR or eFAST means there is a high probability that the patient does not have a PTX and will not need a chest tube.