Bedside Lung Ultrasound as an Independent Tool to Diagnose Pneumonia in Comparison to Chest X-ray: An Observational Prospective Study from Intensive Care Units.

Abstract

Background: Diagnosing pneumonia is challenging because of multiple differential diagnosis. Bedside lung ultrasound (BLUS) is a safe, portable, rapid and inexpensive new modality to diagnose pneumonia. This study was aimed to evaluate the sensitivity of BLUS vs chest X-ray (CXR) to diagnose community-acquired pneumonia (CAP) using computed tomography (CT) scans as the gold standard.

Patients and methods: An observational cross-sectional study was conducted in selected intensive care units (ICUs). Eligible 85 adult patients with symptoms suggestive of pneumonia as per 2007 Infectious Disease Society of America (IDSA), American Thoracic Society (ATS) criteria, and 2D echocardiography were enrolled consecutively by using convenient sampling technique. Real-time reverse transcription-polymerase chain reaction (RT-PCR) assay for SARS-associated coronavirus was sent with in 1 hour followed by BLUS and CXR within 24 hours of ICU admission. The final confirmation of CAP was done by a thoracic CT scan.

Results: Bedside lung ultrasound vs CXR could detect 74 vs 58 cases out of 84 confirmed cases. Sensitivity and specificity of BLUS vs CXR was 88.1% vs 67.8% and 100% vs 0%, respectively. Moreover, LR+ and LR- for BLUS was found to be 0 and 0.12 in comparison to 0.68 and 0 for CXR. The area under receiver operator characteristics (ROC) curve for BLUS vs CXR was 0.94 (95% CI 0.0-1.0) with p = 0.13 and 0.66 (95% CI 0.12-1.0) with p = 0.58. There was a significant agreement between diagnostic accuracy of BLUS and CT scan [kappa value (κ) = 0.14, p = 0.009], whereas CXR could not establish its diagnostic efficiency (κ = -0.023, p = 0.493). Sonographic features of pneumonia were B-lines, shred, and hepatization signs.

Conclusion: It is observed that BLUS showed higher sensitivity, specificity, and diagnostic accuracy as compared to CXR to diagnose pneumonia.

How to cite this article: Dhawan J, Singh G. Bedside Lung Ultrasound as an Independent Tool to Diagnose Pneumonia in Comparison to Chest X-ray: An Observational Prospective Study from Intensive Care Units. Indian J Crit Care Med 2022;26(8):920-929.