Emergency Department Accuracy of Point-of-Care Ultrasound in Identifying Clinically Significant Pneumothorax in High-Severity Trauma Patients

Abstract

Background: Thoracic point-of-care ultrasound (POCUS) is an improved modality for detecting pneumothorax (PTX) with high accuracy compared with supine chest x-ray (CXR) study. However, recent research has questioned the sensitivity of POCUS for diagnosis of PTX in trauma patients.

Objective: The authors determined the accuracy of emergency physician (EP) POCUS in identifying clinically significant PTX in high-severity trauma patients based on the red criteria of the 2021 National Expert Panel on Field Triage.

Methods: The authors conducted a retrospective review of high-severity trauma patients over a 3-year period at a level I trauma center. The presence or absence of PTX was determined by means of computed tomography or a clinician's description of a "rush of air" on tube thoracostomy placement. PTX was defined as clinically significant if the patient required tube thoracostomy within 2.5 h of triage. Diagnostic test characteristics of CXR study and POCUS performed by emergency providers were calculated.

Results: Forty of 924 patients had clinically significant PTX. POCUS identified 26 of 38 patients who survived before computed tomography, for a sensitivity of 68% (95% CI 52-80%), specificity of 100% (95% CI 19.8-100%), positive predictive value of 100% (95% CI 84-100%), and negative predictive value of 14.3% (95% CI 2.5-43.9%). Review of POCUS by fellowship-trained EPs improved sensitivity to 32 of 38 (84%; 95% CI 70-93%), specificity remained the same, PPV was 100% (95% CI 87-100%), and NPV was 25% (95% CI 4.5-64%). Plain CXR study had an overall sensitivity of 48.1% (95% CI 34.2-62.2%) and specificity of 99% (95% CI 97.5-99.6%).

Conclusions: Our results suggest that POCUS is accurate in identifying clinically significant PTX, especially when supervised by fellowship-trained EPs. Less experienced EPs should exercise proper technique in image acquisition and interpretation and may require more supervision by trained EPs. These results highlight the necessity for ongoing real-time quality improvement.

Keywords: emergency medicine; pneumothorax; point-of-care ultrasound; trauma.