The Accuracy of Lung Ultrasonography Versus Chest Radiography for Diagnosis and Follow-up of Pneumonia in Critically Ill Patients

Abstract

Background: Pneumonia is a common and serious infectious disease that can cause high mortality. Lung ultrasonography is being increasingly utilized in emergency and critical settings. The role of Lung Ultrasound (LUS) in the diagnosis and follow-up of pneumonia is becoming more and more important. Aim of the Work: To compare the diagnostic accuracy of LUS against a referent Chest X-Ray (CXR), chest contrastenhanced Computerized Tomography (CT) scan and/or clinical criteria for diagnosis and follow-up of pneumonia in critically ill adult patients. Patients and Methods: We enrolled 32 (11M, 21F) multimorbid patients aged 61.31 ± 12.13 years from March 2016 to October 2016. Each participant underwent CXR and bedside LUS within 6 hours from Intensive Care Unit (ICU) admission. LUS was performed by skilled clinicians, blinded to CXR results and clinical history. The final diagnosis (pneumonia vs. no-pneumonia) was established by another clinician reviewing clinical and laboratory data independent of LUS results and possibly prescribing chest contrast-enhanced CT. Diagnostic parameters of CXR and LUS were compared. Results: 28 patients (87.5%) out of 32 patients with positive LUS had a final diagnosis of pneumonia. LUS was falsely positive in two cases (6.2%) and false negative in two patients (6.2%). The sensitivity and the specificity of LUS were 87.5% (95% CI 78.9-92.7%) and 89.3% (95% CI78.3-91.9%) respectively. Conclusion: The study supports that LUS when conducted by highly-skilled sonographers, performs well for the diagnosis of pneumonia. Intensivist and Emergency Medicine physicians should be encouraged to learn LUS since it appears to be an established diagnostic tool in the hands of experienced physicians.