Diagnostic comparison of bedside lung ultrasound and chest radiography in the intensive care unit

Abstract

Background. Bedside lung ultrasound (POCUS) offers advantages over chest X-ray, including better cost-effectiveness for diagnosing certain pulmonary pathologies. This study compares the diagnostic concordance between portable chest X-rays and bedside lung ultrasounds in the intensive care unit (ICU).

Methods. Adult ICU patients were included. POCUS was performed using the abbreviated BLUE protocol. Diagnostic results from POCUS and chest radiographies were compared using the intensivist clinical diagnosis - based on clinical examinations and lung ultrasounds - as the reference. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the ultrasounds were calculated.

Results. A total of 100 patients were included, 71 with pulmonary pathologies. The average time to perform the ultrasound was 308 seconds. Ultrasound identified pathology in 20 patients with a normal chest radiographs. Diagnostic discrepancies occurred in 30 patients, highlighting ultrasound´s superior sensitivity in detecting atelectasis, pleural effusions, and pulmonary edema. Ultrasound demonstrated sensitivity (S) of 85%, specificity (E) of 100%, positive predictive value (PPV) of 100%, and negative predictive value (NPV) of 55%.

Conclusion. Lung point-of-care ultrasound at ICU admission detects more pathologies and does not miss significant abnormalities seen on chest X-rays. It also shows good diagnostic accuracy. These findings suggest that pulmonary POCUS, using an abbreviated protocol, could be a viable alternative to chest radiography for initial evaluation and follow-up of pulmonary pathologies in critically ill patients, potentially improving care quality and management.