The application of BLUE (bedside lung ultrasound in emergency) protocol in the emergency department

Abstract

Aim: This study aimed to evaluate the effectiveness of lung ultrasonography (US) in detecting the cause of acute respiratory distress in the emergency department. Materials and Methods: This cross-sectional analytical study was carried out on 195 adult patients who were admitted to the Emergency Department of a University Hospital with acute respiratory failure in 6months period. The validity of the US diagnoses was assessed by comparing the decisions made by researchers according to the BLUE protocol classification with the final judgments made by the primary doctors using gold-standard diagnostic techniques suggested by the guidelines. Results: The diagnostic accuracy of chest ultrasound was 89.7%. Specifically, ultrasound demonstrated 95.6% sensitivity and 99% specificity for diagnosing Congestive Heart Failure (CHF), 94.3% sensitivity and 97.2% specificity for Chronic Obstructive Pulmonary Disease (COPD), 94.2% sensitivity and 91.2% specificity for pneumonia, and 100% sensitivity and specificity for Pneumothorax (PTX). In contrast, the sensitivity for Pulmonary Embolism (PE) diagnosis was 66.7%. Ultrasound also identified pneumonia associated with CHF with 83.3% sensitivity and 96.0% specificity, and pneumonia associated with COPD with 54.6% sensitivity and 98.4% specificity. The diagnostic accuracy of routine physical examination and chest X-ray, which are standard for assessing respiratory distress at the bedside in the emergency department, was compared with ultrasound. The accuracy rates for CHF were 89.2%/81.9%/97.4%; for COPD were 90.8%/77.8%/96.4%; for pneumonia were 76.9%/93.8%/92.3%; for PE were 90.8%/90.7%/96.4%; and for PTX were 99.5%/100%/100%, respectively. Additionally, the average time difference between the requests and screenings for X-ray and chest CT was 1.36 hours and 2.26 hours, respectively. Discussion: Our study demonstrated that chest ultrasound is an effective and feasible diagnostic tool for diagnosing CHF, COPD, pneumonia, PE, and PTX. Compared to gold standard tests, ultrasound reduced the diagnostic time and provided more reliable results than physical examination.