Integrating point-of-care ultrasound in the ED evaluation of patients presenting with chest pain and shortness of breath.

Objective: The differential diagnoses of patients presenting with chest pain (CP) and shortness of breath (SOB) are broad and non-specific. We aimed to 1) determine how use of point-of-care ultrasound (POCUS) impacted emergency physicians' differential diagnosis, and 2) evaluate the accuracy of POCUS when compared to chest radiograph (CXR) and composite final diagnosis.

Methods: We conducted a prospective observational study in a convenience sample of patients presenting with CP and SOB to the Emergency Department (ED). Treating physicians selected possible diagnoses from a pre-indexed list of possible diagnoses of causes of CP and SOB. The final composite diagnosis from a chart review was determined as the reference standard for the diagnosis. The primary analysis involved calculations of sensitivity and specificity for POCUS identifiable diagnoses in detecting cause of CP and SOB. Additional comparative accuracy analysis with CXRs were conducted.

Results: 128 patients with a mean age of 64 ± 17 years were included in the study. Using a reference standard of composite final diagnoses, POCUS had equal or higher specificity to CXR for all indications for which it was used, except for pneumonia. POCUS correctly identified all patients with pneumothorax, pleural effusion and pericardial effusion. In patients with a normal thoracic ultrasound, CXR never provided any actionable clinical information. Adding POCUS to the initial evaluation causes a significant narrowing of the differential diagnoses in which the median differential diagnosis from 5 (IQR 3-6) to 3 (IQR 2-4) p < 0.001.

Conclusion: In evaluation of patients with CP and SOB, POCUS is a highly feasible diagnostic test which can assist in narrowing down the differential diagnoses. In patients with a normal thoracic ultrasound, the added value of a CXR may be minimal.