RESUMO
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.