Thoracic point-of-care ultrasound is an accurate diagnostic modality for clinically significant traumatic pneumothorax

Abstract

Objective: There are conflicting data regarding the accuracy of thoracic point-of-care ultrasound (POCUS) in detecting traumatic pneumothorax (PTX). The purpose of our study was to determine the accuracy of thoracic POCUS performed by emergency physicians for the detection of clinically significant PTX in blunt and penetrating trauma patients.

Methods: We conducted a retrospective institutional review board-approved study of trauma patients 15 years or older presenting to our urban Level I academic trauma center from December 2021 to June 2022. All study patients were imaged with single-view chest radiography (CXR) and thoracic POCUS. The presence or absence of PTX was determined by multidetector computed tomography (CT) or CXR and ultrasound (US) with tube thoracostomy placement.

Results: A total of 846 patients were included, with 803 (95%) sustaining blunt trauma. POCUS identified 13/15 clinically significant PTXs (defined as ≥35 mm of pleural separation on a blinded overread or placement of a tube thoracostomy prior to CT) with a sensitivity of 87% (95% confidence interval [CI] 58-97), specificity of 100% (95% CI 99-100), positive predictive value of 81% (95% CI 54%-95%), and negative predictive value of 100% (95% CI 99%-100%). The positive likelihood ratio was 484 and the negative likelihood ratio was 0.1. CXR identified eight (53%) clinically significant PTXs, with a sensitivity of 53% (95% CI 27%-78%) and a specificity of 100%, when correlated with the CT. The most common reason for a missed PTX identified on expert-blinded overread was failure to recognize a lung point sign that was present on US.

Conclusions: Thoracic POCUS accurately identifies the majority of clinically significant PTXs in both blunt and penetrating trauma patients. Common themes for false-negative thoracic US in the expert-blinded overread process identified key gaps in training to inspire US education and medical education research.

Keywords: emergency department; point-of-care ultrasound; thoracic ultrasound; traumatic pneumothorax.