Lung Ultrasound Findings and Algorithms to Detect Pneumonia: A Systematic Review and Diagnostic Testing Meta-Analysis

Area of Science:

• Medical Imaging
• Pulmonology
• Diagnostic Accuracy

Background:

• Lung ultrasound (LUS) is a radiation-free, accessible diagnostic tool for pneumonia.
• Its diagnostic accuracy for various pneumonia types needs comprehensive evaluation.

Purpose of the Study:

• To systematically review and meta-analyze the diagnostic accuracy of individual LUS findings and algorithms for pneumonia.
• To compare LUS performance against chest radiography and CT scans.

Main Methods:

• Systematic search of PubMed, Embase, and Cochrane databases.
• Inclusion of 26 studies (3454 patients) evaluating LUS for community-acquired, hospital-acquired, and ventilator-associated pneumonia (VAP).
• Bivariate linear mixed models and Bayesian analyses for pooling sensitivity, specificity, and likelihood ratios; Quality Assessment of Diagnostic Accuracy Studies-2 tool for bias assessment.

Main Results:

• The Bed Lung Ultrasound in Emergency (BLUE) protocol achieved the highest sensitivity (88%).
• Dynamic air bronchograms demonstrated the highest specificity (96%).
• Focal B-lines showed low sensitivity (24%) but high specificity (96%). LUS specificity decreased in VAP patients.

Conclusions:

• Lung ultrasound is a valuable tool for diagnosing community-acquired and hospital-acquired pneumonia.
• LUS utility is limited in diagnosing VAP, necessitating complementary diagnostic methods.
• This meta-analysis is the first to evaluate the specificity and sensitivity of individual LUS findings for pneumonia.