Diagnostic accuracy of chest ultrasound in patients with pneumonia in the intensive care unit: A single‐hospital study

Abstract

Background and aims

Chest radiography (CXR) and computerized tomography (CT) scan are the preferred methods for lung imaging in diagnosing pneumonia in the intensive care unit, in spite of their limitations. The aim of this study was to assess the performance of bedside lung ultrasound examination by a critical care physician, compared with CXR and chest CT, in the diagnosis of acute pneumonia in the ICU.

Materials and Methods

This was an observational, prospective, single‐center study conducted in the intensive care unit of Ahmadi General Hospital. Lung ultrasound examinations (LUSs) were performed by trained critical care physicians, and a chest radiograph was interpreted by another critical care physician blinded to the LUS results. CT scans were obtained when clinically indicated by the senior physician.

Results

Out of 92 patients with suspected pneumonia, 73 (79.3%) were confirmed to have a diagnosis of pneumonia based on radiological reports, clinical progress, inflammatory markers, and microbiology studies. Of the 73 patients, 31 (42.5%) were male, with a mean age of 68.3 years, and a range of 27 to 94 years. Eleven (15%) patients had community‐acquired pneumonia, and 62 (85%) had hospital‐acquired pneumonia. In the group of patients with confirmed pneumonia, 72 (98.6%) had LUSs positive for consolidation (sensitivity 98.6%, 95% CI 92.60%‐99.97%), and in the group without pneumonia, 16 (85%) had LUS negative for consolidation (specificity 84.2%, 95% CI 60.42%‐96.62%), compared with 40 (55%) with CXRs positive for consolidation (sensitivity 54.8%, 95% CI 42.70%‐66.48%) and 33 (45%) with CXRs negative for consolidation (specificity 63.16%, 95% CI 38.36%‐83.71%).

A chest CT was performed in 38 of the 92 enrolled patients and was diagnostic for pneumonia in 32 cases. LUSs were positive in 31 of 32 patients with CT‐confirmed pneumonia (sensitivity 96%), and CXR was positive in 5 of 32 patients with CT‐confirmed pneumonia (sensitivity 15.6%).

Conclusion

Bedside lung ultrasound is a reliable and accurate tool that appears to be superior to CXR for diagnosing pneumonia in the ICU setting. LUS allows for a faster, non‐invasive, and radiation‐free method to diagnose pneumonia in the ICU.