Lung Ultrasonography Versus Chest X Ray for Diagnosing Pneumonia in Children with Fever and Respiratory Distress: A Prospective Blind Study

Abstract

Pneumonia is a major cause of morbidity and mortality in children especially in developing countaries. Lung ultrasonography (LUS) is an accepted safe diagnostic tool with many advantages over chest x-ray (CXR). The objective of this prospective observational study was to evaluate the usefulness of LUS in comparison with CXR for diagnosing pneumonia in 60 children presented with fever and respiratory distress. For each patient complete diagnostic workup was performed including history, physical examination, routine laboratory investigations, CXR and LUS. LUS was performed by a sonographer blinded to patient’s clinical and CXR findings. The patients were classified into; <i>Pneumonia group</i>: included 45 patients diagnosed by two clinicians as having community acquired pneumonia (CAP) based on the recommendations of British Thoracic Society and <i>Non pneumonia group</i>: included 15 patients received other diagnoses. The clinicians were blinded to CXR and LUS findings. In pneumonia group, sonographic and radiographic findings compatible with pneumonia were found in 95.6% and 88.9% of patients respectively. In non pneumonia group, LUS can exclude pneumonia in 93.3% of patients while CXR excluded pneumonia in 86.7% of them. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of LUS to demonstrate lung involvement were higher than those of CXR (95.6%, 93.3%, 97.7%, 85.7% and 94.5% versus 88.9%, 86.7%, 95.2%, 72.2% and 86.7% respectively). LUS was superior to CXR in identifying pleural effusion and multiple consolidation in more than one lobe. Being safer, cheaper and relatively more time saving, lung ultrasonography offers an important contribution to the diagnosis of CAP in febrile children with respiratory distress compared to chest X-ray.