Ultrasound in Emergency Medicine
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

https://doi.org/10.1016/j.jemermed.2018.09.009Get rights and content

Abstract

Background

Lung ultrasound can accelerate the diagnosis of life-threatening diseases in adults with respiratory symptoms.

Objective

Systematically review the accuracy of lung ultrasonography (LUS) for emergency diagnosis of pneumonia, acute heart failure, and exacerbation of chronic obstructive pulmonary disease (COPD)/asthma in adults.

Methods

PubMed, Embase, Scopus, Web of Science, and LILACS (Literatura Latino Americana e do Caribe em Ciências da Saúde; until 2016) were searched for prospective diagnostic accuracy studies. Rutter-Gatsonis hierarchical summary receiver operating characteristic method was used to measure the overall accuracy of LUS and Reitsma bivariate model to measure the accuracy of the different sonographic signs. This review was previously registered in PROSPERO (Centre for Reviews and Dissemination, University of York, York, UK; CRD42016048085).

Results

Twenty-five studies were included: 14 assessing pneumonia, 14 assessing acute heart failure, and four assessing exacerbations of COPD/asthma. The area under the summary receiver operating characteristic curve of LUS was 0.948 for pneumonia, 0.914 for acute heart failure, and 0.906 for exacerbations of COPD/asthma. In patients suspected to have pneumonia, consolidation had sensitivity of 0.82 (95% confidence interval [CI] 0.74–0.88) and specificity of 0.94 (95% CI 0.85–0.98) for this disease. In acutely dyspneic patients, modified diffuse interstitial syndrome had sensitivity of 0.90 (95% CI 0.87–0.93) and specificity of 0.93 (95% CI 0.91–0.95) for acute heart failure, whereas B-profile had sensitivity of 0.93 (95% CI 0.72–0.98) and specificity of 0.92 (95% CI 0.79–0.97) for this disease in patients with respiratory failure. In patients with acute dyspnea or respiratory failure, the A-profile without PLAPS (posterior-lateral alveolar pleural syndrome) had sensitivity of 0.78 (95% CI 0.67–0.86) and specificity of 0.94 (95% CI 0.89–0.97) for exacerbations of COPD/asthma.

Conclusion

Lung ultrasound is an accurate tool for the emergency diagnosis of pneumonia, acute heart failure, and exacerbations of COPD/asthma.

Introduction

Acute respiratory symptoms are frequent causes of emergency department (ED) visits, and respiratory impairment is a leading cause of hospital ward and intensive care unit (ICU) admissions. The differential diagnosis includes common pulmonary and cardiovascular diseases such as pneumonia, exacerbations of chronic pulmonary diseases, and acute heart failure syndromes, which may lead to rapid clinical deterioration. Thus, an immediate and accurate diagnosis is critical, because failure of, or delay in, diagnoses and treatment can have detrimental effects on patients. Delay in administering adequate antimicrobial therapy can increase the mortality in patients with pneumonia, and inadequate administration of beta-agonists can impair the cardiovascular function in patients with acute heart failure 1, 2.

Chest radiography (CXR) is currently the first diagnostic imaging approach in patients with acute respiratory symptoms. However, several studies report CXR having poor sensitivity for detecting common respiratory diseases such as pneumonia and pulmonary edema from acute heart failure 3, 4. Chest computed tomography (CCT) overcomes this limitation but increases costs and exposure to radiation, and patients need to be transported to the radiology department (5).

In the past decade, lung ultrasound (LUS) has attracted attention in emergency and intensive care medicine. It is radiation free, can be performed at the bedside in a few minutes, and can be interpreted in real time for multiple diagnoses. Along with other point-of-care ultrasound modalities, LUS accelerates the diagnostic process, increases the rate of correct diagnoses, and ensures appropriate treatment in the first hours after arrival at the ED 6, 7. However, diagnostic accuracy studies have assessed different sonographic signs and subgroups of patients, with different values of sensitivity and specificity, even for the same target disease 8, 9, 10.

The aim of this systematic review and meta-analysis was to assess the accuracy of LUS for the emergency diagnosis of the most common diseases in adults with respiratory symptoms. We systematically reviewed the literature for prospective diagnostic accuracy studies of LUS for pneumonia, acute heart failure, and exacerbations of chronic obstructive pulmonary disease (COPD)/asthma. In addition to the overall diagnostic accuracy of LUS for these diseases, we measured the individual diagnostic accuracy of the different sonographic signs that were presented in the literature.

Section snippets

Materials and Methods

The protocol of this review was prospectively registered in the International Prospective Register of Systematic Reviews (PROSPERO; Centre for Reviews and Dissemination, University of York, York, UK; CRD42016048085). The review is reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (11).

Two independent authors (LJS and RRMB) selected the studies, extracted their data, and assessed their risk of bias and applicability concerns.

Characteristics of the Included Studies

From the 11,017 titles and abstracts screened, 25 studies involving 4241 patients were included. Fourteen studies assessed pneumonia (n = 1867 patients), 14 assessed acute heart failure (n = 2778 patients), and four studies assessed exacerbation of COPD or asthma (n = 527 patients) 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40. Figure 1 shows the study selection process.

All included studies were published between 2008 and 2016. Most of them

Discussion

This study systematically reviewed the available literature for prospective studies on the accuracy of the LUS for the emergency diagnosis of pneumonia, acute heart failure, and exacerbations of COPD/asthma. Twenty-five studies were included, most of which had assessed pneumonia and acute heart failure. The studies were heterogeneous in their characteristics and results, and the overall methodological quality was low, demanding cautious interpretation of the findings. The meta-analysis suggests

Conclusions

LUS has high accuracy for pneumonia, acute heart failure, and exacerbation of COPD/asthma, and seems to be a valuable complement to other diagnostic methods in the emergency diagnosis of these diseases in adults with respiratory symptoms. The interpretation of the LUS examination should take into account the accuracy of the individual sonographic signs to diagnose pneumonia and acute heart failure.

Article Summary

1. Why is this topic important?

  1. Pneumonia, acute heart failure, and exacerbation of chronic obstructive pulmonary disease

Acknowledgment

The authors appreciate the assistance of Maria Gorete Monteguti Savi for her help with the database search strategy.

References (48)

  • R. Nafae et al.

    Adjuvant role of lung ultrasound in the diagnosis of pneumonia in intensive care unit-patients

    Egypt J Chest Dis Tuberc

    (2013)
  • P. Nazerian et al.

    Accuracy of lung ultrasound for the diagnosis of consolidations when compared to chest computed tomography

    Am J Emerg Med

    (2015)
  • S. Parlamento et al.

    Evaluation of lung ultrasound for the diagnosis of pneumonia in the ED

    Am J Emerg Med

    (2009)
  • K.L. Anderson et al.

    Diagnosing heart failure among acutely dyspneic patients with cardiac, inferior vena cava, and lung ultrasonography

    Am J Emerg Med

    (2013)
  • E. Pivetta et al.

    Lung ultrasound-implemented diagnosis of acute decompensated heart failure in the ED: a SIMEU multicenter study

    Chest

    (2015)
  • E.E. Unluer et al.

    Lung ultrasound by emergency nursing as an aid for rapid triage of dyspneic patients: a pilot study

    Int Emerg Nurs

    (2014)
  • D.A. Lichtenstein

    BLUE-protocol and FALLS-protocol: two applications of lung ultrasound in the critically ill

    Chest

    (2015)
  • J. Gullett et al.

    Interobserver agreement in the evaluation of B-lines using bedside ultrasound

    J Crit Care

    (2015)
  • L.A. Mandell et al.

    Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults

    Clin Infect Dis

    (2007)
  • C.S. Wang et al.

    Does this dyspneic patient in the emergency department have congestive heart failure?

    JAMA

    (2005)
  • A.M. Llamas-Álvares et al.

    Accuracy of lung ultrasonography in the diagnosis of pneumonia in adults: systematic review and meta-analysis

    Chest

    (2017)
  • M.A. Chavez et al.

    Lung ultrasound for the diagnosis of pneumonia in adults: systematic review and meta-analysis

    Respir Res

    (2014)
  • J.L. Martindale et al.

    Diagnosing acute heart failure in the emergency department: a systematic review and meta-analysis

    Acad Emerg Med

    (2016)
  • D. Moher et al.

    Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement

    Ann Intern Med

    (2009)
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