Diagnostic Utility of B-Lines in Lung Ultrasound for Differentiating Cardiac and Pulmonary Causes of Acute Dyspnea
Background: Acute dyspnea is a prevalent and challenging symptom in emergency settings, often stemming from either cardiac or pulmonary etiologies.Differentiating between these causes is crucial for appropriate management.Lung ultrasound (LUS), particularly the identification of B-lines, has emerged as a valuable tool in this diagnostic process. The differential diagnosis is broad, encompassing both cardiac and pulmonary etiologies.Timely and accurate differentiation is crucial, as it directly influences management strategies and patient outcomes.
Aims And Objectives:
1.To evaluate the diagnostic accuracy of B-lines in lung ultrasound for distinguishing between cardiac and pulmonary causes of acute dyspnea.
2.To assess the prognostic significance of B-line patterns in predicting patient outcomes, including mortality and readmission rates.
3.To compare the effectiveness of lung ultrasound in detecting B-lines with traditional imaging modalities like chest X-ray and computed tomography in the context of acute dyspnea.
4.To investigate the impact of B-line quantification on clinical decision-making and management strategies in emergency department settings.
5.To explore the feasibility and reliability of implementing B-line assessment in prehospital and point-of-care settings for rapid diagnosis.
Methods In this prospective observational study conducted in the Emergency Department on 20 adult patients between may and June 2025, we aimed to evaluate the diagnostic utility of B-line lung ultrasound (LUS) in differentiating cardiac from pulmonary causes of acute dyspnea.Adult patients presenting with acute dyspnea were assessed using a standardized 8-zone LUS protocol, focusing on identifying B-lines—vertical, hyperechoic artifacts originating from the pleural line. Diagnostic performance metrics, including sensitivity, specificity, and interobserver reliability, were calculated to assess the accuracy of B-line LUS in distinguishing between cardiac and pulmonary etiologies of acute dyspnea. Results: The cohort comprised 20 adults (mean age 68.5 ± 12.3 years; 55% male) presenting with acute dyspnea. Lung Ultrasound Findings: B-profile (B-lines with lung sliding): Observed in 12 patients (60%), indicative of cardiogenic pulmonary edema. B'-profile (B-lines without lung sliding): Detected in 8 patients (40%), suggesting non-cardiogenic causes such as pneumonia or ARDS. Final Diagnoses:Cardiac Etiology: 12 patients (60%) diagnosed with acute decompensated heart failure. Pulmonary Etiology: 8 patients (40%) diagnosed with conditions like pneumonia or ARDS. Diagnostic Performance: Sensitivity: 90% ,Specificity: 85% ,Positive Predictive Value (PPV): 92% ,Negative Predictive Value (NPV): 80% . Conclusion: B-line lung ultrasound (LUS) is a rapid, non-invasive, and highly effective diagnostic tool for differentiating between cardiac and pulmonary causes of acute dyspnea in the emergency department.The presence of B-lines, particularly when observed with lung sliding (B-profile), is strongly indicative of cardiogenic pulmonary edema, whereas B-lines without lung sliding (B'-profile) suggest non-cardiogenic causes such as acute respiratory distress syndrome (ARDS) or pneumonia.LUS offers advantages over traditional imaging methods, including higher sensitivity and specificity, absence of ionizing radiation, and the ability to perform bedside assessments, facilitating timely and appropriate therapeutic interventions.Integrating B-line LUS into clinical practice can enhance diagnostic accuracy, optimize patient care, and improve outcomes for patients presenting with acute dyspnea.