TOPLINE:

Lung ultrasound (LUS) demonstrated good diagnostic performance in identifying an adjudicated bacterial component in children with acute lower respiratory tract infections, and when combined with C-reactive protein (CRP), it may have contributed to more rational antibiotic decision-making.

METHODOLOGY:

• Researchers conducted a single-centre prospective observational study to evaluate the diagnostic role of LUS, alone or combined with CRP, in identifying a clinically adjudicated bacterial component in children with acute lower respiratory tract infections.
• They included 160 children aged 1 month to 19 years who were hospitalised with symptoms of acute lower respiratory tract infections lasting more than 24 hours at a tertiary referral centre in the Czech Republic between December 2022 and April 2024.
• Acute respiratory illness included cough, fever > 38 °C, tachypnoea, dyspnoea, chest pain, abnormal auscultation, and oxygen requirement.
• LUS was performed within 24 hours of admission by a physician blinded to all clinical, laboratory, and radiologic findings. LUS findings stratified patients into presumed viral, bacterial, or mixed aetiologic categories on the basis of predefined imaging criteria.
• Final aetiologic classification was determined by three senior paediatricians blinded to LUS results using an adjudicated composite reference standard integrating clinical course, laboratory markers, microbiology, and chest radiography.

TAKEAWAY:

• On the basis of the adjudicated composite reference standard, 46.9% of patients were classified as viral, 37.5% were classified as combined bacterial-viral, and 15.6% were classified as bacterial.
• LUS identified a bacterial component with good diagnostic performance, with an area under the receiver operating characteristic curve (AUROC) of 0.89, a sensitivity of 83.5%, and a specificity of 94.6%.
• A CRP level of ≥ 40 mg/L also showed comparable performance in identifying a bacterial component, with an AUROC of 0.91, a sensitivity of 75.3%, and a specificity of 94.7%.
• Large lung consolidations (≥ 20 mm), bronchograms, confluent B-lines, and pleural effusions were associated with bacterial components, whereas viral cases were characterised by small, bilateral subpleural consolidations and diffuse non-confluent B-lines.

IN PRACTICE:

"Our findings support the use of LUS as a first-line imaging modality in children hospitalized with ALRTIs [acute lower respiratory tract infections], particularly when interpreted in conjunction with CRP. This approach may facilitate early, pathogen-oriented stratification at hospital admission, help reduce unnecessary antibiotic prescribing, and decrease reliance on radiographic imaging," the authors wrote.

SOURCE:

This study was led by Jiří Fremuth, Faculty Hospital, Faculty of Medicine in Pilsen, Charles University, Pilsen, Czech Republic. It was published online on June 03, 2026, in the European Journal of Pediatrics.

LIMITATIONS:

The single-centre design may have limited the generalisability of the findings. The relatively small sample size reduced statistical power. A single experienced operator performed all LUS examinations and did not assess variability between different observers.

DISCLOSURES:

The study did not explicitly mention the funding source. The authors declared having no competing interests.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.