Accuracy of Bedside Lung Ultrasound in Emergency (BLUE) Protocol to Diagnose the Cause of Acute Respiratory Distress Syndrome (ARDS): A Meta-Analysis

Oke Dimas Asmara, Ceva Wicaksono Pitoyo, Vally Wulani, Kuntjoro Harimurti, Abrianty P Araminta


Background: There is a stigma that ultrasound cannot be used to see abnormalities in the air-filled organs makes ultrasound rarely used to identify lung abnormalities. This study purpose comparing diagnostic accuracy of BLUE protocol with gold standard for each diagnosis causing acute respiratory failure. Methods: Systematic search was done in 6 databases (Pubmed/MEDLINE, Embase, Cochrane Central, Scopus, Ebscohost/CINAHL dan Proquest) and multiple grey-literature sources for cross-sectional studies. We manually extracted the data from eligible studies and calculated pooled sensitivity, pooled specificity, likelihood ratio (LR) and diagnostic odds ratio (DOR). We follow PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guideline throughout these processes. Results: Four studies has been picked from total 509 studies involved. The results yield parameters indicating BLUE protocol as a reliable modality to diagnose pneumonia with pooled sensitivity 84% (95% CI, 76-89%),  pooled specificity 98%  (95% CI, 93-99%), LR+ 42 (95% CI, 12-147), LR- 0.12 (95% CI, 0.07-0.2) and DOR 252 (95% CI, 81-788), respectively. It also considerably applicable to diagnose pulmonary oedema with pooled sensitivity 89% (95% CI, 81-93%), pooled specificity 94% (95% CI, 89-96%), LR+ 14 (95% CI, 8-25), LR- 0.165 (95% CI, 0.11-0.24), and DOR 116 (95% CI, 42-320), respectively. Conclusion: BLUE protocol has good diagnostic accuracy to diagnose pneumonia and pulmonary oedema. We recommend implementing BLUE protocol as a tool in evaluating cause of ARF.


Ultrasonography; BLUE protocol; Accuracy; Respiratory Failure; Meta-analysis


Peris A, Tutino L, Zagli G, et al. The use of point-of-care bedside lung ultrasound significantly reduces the number of radiographs and computed tomography scans in critically ill patients. Anesth Analg 2010;111.

Zanobetti M, Scorpiniti M, Gigli C, et al. Point-of-care ultrasonography for evaluation of acute dyspnea in the ED. Chest. 2017;151.

Cochi SE, Kempker JA, Annangi S, et al. Mortality trends of acute respiratory distress syndrome in the United States from 1999 to 2013. Ann Am Thorac Soc. 2016;13.

Lichtenstein DA. Lung ultrasound in critically ill. Ann Intensive Care. 2014;30.

Leidi A, Rouyer F, Marti C, et al. Point of care ultrasonography from the emergency department to the internal medicine ward: current trends and perspectives. Intern Emerg Med. 2020;15.

Silva S, Biendel C, Ruiz J, et al. Usefulness of cardiothoracic chest ultrasound in the management of acute respiratory failure in critical care practice. Chest. 2013;144.

Chavez MA, Shams N, Ellington LE, et al. Lung ultrasound for the diagnosis of pneumonia in adults: A systematic review and meta-analysis. Respir Res. 2014;15.

Volpicelli G, Elbarbary M, Blaivas M, et al. International evidence-based recommendations for point-of-care lung ultrasound. Intensive Care Med. 2012;38.

Vignon P, Repessé X, Vieillard-Baron A, et al. Critical care ultrasonography in acute respiratory failure. Crit Care. 2016;20.

Lichtenstein D. Lung ultrasound in acute respiratory failure an introduction to the BLUE-protocol. Minerva Anestesiol. 2009;75.

Lichtenstein DA, Mezière GA. Relevance of lung ultrasound in the diagnosis of acute respiratory failure the BLUE protocol. Chest. 2008;134.

Dexheimer Neto FL, Andrade JMS de, Raupp ACT, et al. Diagnostic accuracy of the Bedside Lung Ultrasound in Emergency protocol for the diagnosis of acute respiratory failure in spontaneously breathing patients. J Bras Pneumol. 2015;41.

Bekgoz B, Kilicaslan I, Bildik F, et al. BLUE protocol ultrasonography in Emergency Department patients presenting with acute dyspnea. Am J Emerg Med. 2019;37.

Danish M, Agarwal A, Goyal P, et al. Diagnostic performance of 6-point lung ultrasound in ICU patients: A comparison with chest X-ray and CT thorax. Turkish J Anaesthesiol Reanim. 2019;47.

Patel CJ, Bhatt HB, Parikh SN, et al. Bedside lung ultrasound in emergency protocol as a diagnostic tool in patients of acute respiratory distress presenting to emergency department. J Emergencies Trauma Shock. 2018;11.

Ye X, Xiao H, Chen B, et al. Accuracy of lung ultrasonography versus chest radiography for the diagnosis of adult community-acquired pneumonia: Review of the literature and meta-analysis. PLoS One. 2015;10.

Long L, Zhao H-T, Zhang Z-Y, et al. Lung ultrasound for the diagnosis of pneumonia in adults. Med. 2017;96.

Llamas-Álvarez AM, Tenza-Lozano EM, Latour-Pérez J. Accuracy of lung ultrasonography in the diagnosis of pneumonia in adults: Systematic review and meta-analysis. Chest. 2017;151.

Cibinel GA, Casoli G, Elia F, et al. Diagnostic accuracy and reproducibility of pleural and lung ultrasound in discriminating cardiogenic causes of acute dyspnea in the Emergency Department. Intern Emerg Med. 2012;7.

Lichtenstein D. Novel approaches to ultrasonography of the lung and pleural space: Where are we now?. Breathe. 2017;13.

Narendra DK, Hess DR, Sessler CN, et al. Update in management of severe hypoxemic respiratory failure. Chest. 2017;152.

Xirouchaki N, Kondili E, Prinianakis G, et al. Impact of lung ultrasound on clinical decision making in critically ill patients. Intensive Care Med. 2014;40.

Seyedhosseini J, Bashizadeh-fakhar G, Farzaneh S, et al. The impact of the BLUE protocol ultrasonography on the time taken to treat acute respiratory distress in the ED. Am J Emerg Med. 2017;35.

Seif D, Perera P, Mailhot T, et al. Bedside ultrasound in resuscitation and the rapid ultrasound in shock protocol. Crit Care Res Pract. 2012;2012.

Lichtenstein DA. BLUE-Protocol and FALLS-Protocol: Two applications of lung ultrasound in the critically ill. Chest. 2015;147.

Staub LJ, Mazzali Biscaro RR, Kaszubowski E, et al. Lung ultrasound for the emergency diagnosis of pneumonia, acute heart failure, and exacerbations of chronic obstructive pulmonary disease/asthma in adults: A systematic review and meta-analysis. J Emerg Med. 2019;56.

Wooten WM, Shaffer LET, Hamilton LA. Bedside ultrasound versus chest radiography for detection of pulmonary edema: A prospective cohort study. J Ultrasound Med. 2019;38.

Al Deeb M, Barbic S, Featherstone R, et al. Point-of-care ultrasonography for the diagnosis of acute cardiogenic pulmonary edema in patients presenting with acute dyspnea: A systematic review and meta-analysis. Acad Emerg Med. 2014;21.

Abdalla W, Elgendy M, Abdelaziz AA, et al. Lung ultrasound versus chest radiography for the diagnosis of pneumothorax in critically ill patients: A prospective, single-blind study. Saudi J Anaesth. 2016;10.

Lichtenstein DA, Mezière GA, Lagoueyte JF, et al. A-lines and B-lines: Lung ultrasound as a bedside tool for predicting pulmonary artery occlusion pressure in the critically ill. Chest. 2009;136.

Huang D, Ma H, Xiao Z, et al. Diagnostic value of cardiopulmonary ultrasound in elderly patients with acute respiratory distress syndrome. BMC Pulm Med. 2018;18.

Ranieri VM, Rubenfeld GD, Thompson BT, et al. Acute respiratory distress syndrome: The Berlin definition. JAMA - J Am Med Assoc. 2012;307.

Soldati G, Demi M, Demi L. Ultrasound patterns of pulmonary edema. Ann Transl Med. 2019;7.

Saraogi A. Lung ultrasound: present and future. Lung India. 2015;32.

Prosen G, Klemen P, Strnad M, et al. Combination of lung ultrasound (a comet-tail sign) and N-terminal pro-brain natriuretic peptide in differentiating acute heart failure from chronic obstructive pulmonary disease and asthma as cause of acute dyspnea in prehospital emergency setting. Crit Care. 2011;15.

Schünemann HJ, Mustafa R, Brozek J, et al. GRADE Guidelines: 16. GRADE evidence to decision frameworks for tests in clinical practice and public health. J Clin Epidemiol. 2016;76.

Full Text: PDF


  • There are currently no refbacks.

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.