Diagnostic Accuracy of Lung Ultrasonography Compared to Chest Radiography, BNP and Physical Examination in Patients with Dyspnea Suggestive of Pulmonary Edema: A Systematic Review and Meta-Analysis

Background: Pulmonary edema (PE) is the result of an abrupt increase in hydrostatic pressure in the pulmonary capillaries that leads to leakage of fluid through microvascular endothelial cells. This leads to a disruption of gas exchange in the lungs. Aims: This meta-analysis aimed to determine the diagnostic accuracy of lung ultrasonography (LUS) in pulmonary edema. Methods: A systematic search was conducted using a strategy based on these search terms (Lung ultrasonography, pulmonary edema, diagnostic accuracy); we searched PubMed, Google Scholar, and the Cochrane Library. Out of 1029, 14 prospective cross-sectional and observational studies with 2239 patients who reported the sensitivity and specificity of lung ultrasonography in diagnosing pulmonary edema were selected. For inclusion and data extraction, an independent review of citations was carried out. The data obtained were analyzed using SPSS, RevMan 5.3, and Stata 14.0 software. A quality assessment was conducted using the QUADAS-2 tool. The reference gold standard was the final clinical diagnosis according to chest radiography, B-type natriuretic peptide, and/or physical examination in dyspneic patients. Results: The overall sensitivity and specificity of lung ultrasonography in the diagnosis of pulmonary edema were 0.86 (95% CI, 0.81-0.90) and 0.91 (95% CI, 0.90-0.93), respectively, with a Younden index of 77.8%. The area under the receiver operating characteristic (ROC) curve was 0.889. Conclusion: The overall diagnostic odds ratio was 68.86. The results of this meta-analysis suggest that lung ultrasonography is an effective non-invasive technique in the diagnosis of acute pulmonary edema with rapid bedside examination and immediate interpretation.