Usefulness of Emergency Departmentbedside Lung Ultrasound in Emergency (ED-BLUE) Protocol for Patients Complaining of Dyspnea in the Emergency Department

Abstract

Purpose: The bedside lung ultrasound in emergency (BLUE) protocol is an excellent diagnostic tool for acute respiratory failures requiring admission to the intensive care unit. We incorporated cardiac ultrasound in the BLUE algorithm because cardiac origin is also necessary to examine in an emergency setting. We studied the usefulness of the emergency department (ED)-BLUE protocol for patients complaining of dyspnea in an emergency department. Methods: At first, we assessed lung sliding, artifacts (Alines and B-lines), alveolar consolidation and pleural effusion on stage I and II evaluation. Then, we checked heart to detect 3Es (Effusion, Equality, and Ejection fractions). We divided all the possible conditions into 10 categories. We compared it with final diagnosis and examined the agreements using kappa statistics. We compared the physician’s level of confidence for the first impression. The 10 categories were: 1) normal or inconclusive, 2) pulmonary embolism, 3) airway disease (chronic obstructive pulmonary disease or asthma), 4) pneumothorax, 5) large pleural effusion, 6) alveolar consolidation, 7) acute pulmonary edema due to systolic congestive heart failure, 8) acute respiratory distress syndrome, 9) chronic interstitial lung disease with exacerbation, and 10) pericardial effusion with/without tamponade. Results: This prospective study was performed for 172 patients over 18-years-of-age with dyspnea during a 25-month period. Kappa value between the diagnosis after ED-BLUE and final diagnosis was 0.812(p<0.001). The mean of physician’s full term for LOC for the first impression before and after ED-BLUE was 3.09±0.83 and 4.36±0.70(paired t-test, p<0.001). Conclusion: ED-BLUE protocol could help the emergency physician make an accurate diagnosis in patients with dyspnea in the emergent setting.