Background Current UK (British Thoracic Society, 2005) guidance recommends that CT is not routinely used in the initial investigation of pleural effusion in children. Ultrasound is recommended to confirm the presence of pleural fluid and to guide drain insertion. However, optimal imaging is also essential in delineating ‘simple’ parapneumonic pleural effusion from necrotising pneumia with complications.
Method We review the evidence comparing ultrasound to CT imaging for paediatric pleural effusion and present four cases where early CT imaging could have altered clinical outcomes.
Results Three cases presented with complete unilateral ‘white-out’ on chest X-ray, limiting the information available about the underlying lung parenchyma from that modality. These patients had a total of six ultrasound scans, only one of which identified underlying parenchymal complications. All three patients had evidence of necrotic pneumonia; one developed a pneumatocele post percutaneous drainage; two required surgical management and had evidence of bronchopulmonary fistula formation, one in conjunction with diaphragmatic necrosis and perforation. The fourth patient had a discrepancy between chest X-ray and ultrasound findings and also went on to develop pneumatocele following percutaneous drainage.
Discussion Previously published evidence and our case series show that ultrasound is less successful than CT at identifying lung necrosis in the setting of paediatric pleural effusion. The early use of CT may help to reduce length of hospital stay by avoiding inappropriate percutaneous drainage and subsequent complications or by prompting earlier surgical intervention.