BLUE protocol ultrasonography in Emergency Department patients presenting with acute dyspnea

Am J Emerg Med. 2019 Nov;37(11):2020-2027. doi: 10.1016/j.ajem.2019.02.028. Epub 2019 Feb 20.


Objective: Dyspnea is a common Emergency Department (ED) symptom requiring prompt diagnosis and treatment. The bedside lung ultrasonography in emergency (BLUE) protocol is defined as a bedside diagnostic tool in intensive care units. The aim of this study was to investigate the test performance characteristics of the BLUE-protocol ultrasonography in ED patients presenting with acute dyspnea.

Method: This study was performed as a prospective observational study at the ED of a tertiary care university hospital over a 3-month period. The BLUE-protocol was applied to all consecutive dyspneic patients admitted to the ED by 5 emergency physicians who were certified for advanced ultrasonography. In addition to the BLUE-protocol, the patients were also evaluated for pleural and pericardial effusion.

Results: A total of 383 patients were included in this study (mean age, 65.5 ± 15.5 years, 183 (47.8%) female and 200 (52.2%) male). According to the BLUE-protocol algorithm, the sensitivities and specificities of the BLUE-protocol are, respectively, 87.6% and 96.2% for pulmonary edema, 85.7% and 99.0% for pneumonia, 98.2% and 67.3% for asthma/COPD, 46.2% and 100% for pulmonary embolism, and 71.4% and 100% for pneumothorax. Although not included in the BLUE-protocol algorithm, pleural or pericardial effusion was detected in 82 (21.4%) of the patients.

Conclusion: The BLUE-protocol can be used confidently in acute dyspneic ED patients. For better diagnostic utility of the BLUE-protocol in EDs, it is recommended that the BLUE-protocol be modified for the assessment of pleural and pericardial effusion. Further diagnostic evaluations are needed in asthma/COPD groups in terms of the BLUE-protocol.

Keywords: BLUE protocol; Bedside lung ultrasonography; Dyspnea; Emergency Department.

Publication types

  • Observational Study

MeSH terms

  • Acute Disease
  • Adult
  • Aged
  • Aged, 80 and over
  • Algorithms
  • Clinical Protocols
  • Cross-Sectional Studies
  • Dyspnea / diagnostic imaging*
  • Dyspnea / etiology
  • Emergency Service, Hospital*
  • Female
  • Humans
  • Lung / diagnostic imaging*
  • Lung Diseases / complications
  • Lung Diseases / diagnostic imaging*
  • Male
  • Middle Aged
  • Point-of-Care Testing*
  • Prospective Studies
  • Sensitivity and Specificity
  • Ultrasonography