Ultrasound for identification of pleural fluid in pneumonia

Abstract

It can be difficult to definitively differentiate between pleural effusion and empyema versus infiltrate alone on plain chest radiographs of patients. However, this is a clinically important distinction that drives optimal therapy, as large fluid collections are unlikely to resolve with antibiotic therapy alone and usually require drainage. A four-year-old male arrived for evaluation of 5 days of fever and cough. The cough was non-productive and associated with postural difficulty in breathing, which improved when leaning on his right side. Vital signs revealed tachycardia, tachypnoea, afebrile, and SpO2 100% at room air. Physical examination revealed an alert patient in moderate to severe respiratory distress, nasal flaring, and purulent rhinorrhoea bilaterally. Lung examination revealed a dull percussion note over the right lung field and significantly decreased air entry. A chest radiograph revealed a large area of opacity involving the right chest. The working diagnosis was right-sided pneumonia with empyema. The differential diagnosis included tuberculosis with pleural effusion. A focused bedside ultrasound revealed dense lung consolidation without significant associated fluid collection. Given this additional diagnostic information, the management planned was altered and the intercostal drain placement aborted. Sonographic evaluation of the lungs is well described in medical literature and has been used in patients to assess for pneumothorax, pleural effusion, pulmonary oedema, and lung consolidation. Even in settings where advanced imaging options are available, emergency sonography has several features that make it an attractive option for the acute care provider. In the resource-limited setting, the utility of emergency sonography is enhanced, especially when other imaging modalities are unavailable or cost prohibitive. Focused point-of-care sonography is a useful adjunct to clinical examination that may augment clinical decision-making and safely avoid unnecessary invasive procedures.