Cough and tachypnoea in a toddler

In part 1 we reported how a 17-month-old girl became rapidly ill with cough, pyrexia and respiratory distress. A chest X-ray showed air—fluid cavities in the right hemithorax. Ventilation became necessary and a post-intubation chest radiograph unexpectedly showed an increase in the size and number of cavities in the right hemithorax (Figure 1).

Figure 1.

Pre-intubation chest radiograph

Figure 3.

CT scan of chest after exploratory surgery. This cross-section is a slice at a level below the tracheal bifurcation. Several cavities can be seen (asterisks) in the right middle lobe. There is also collapse and consolidation of middle lobe segments behind these cavities and a right pleural effusion

The child was transferred to our paediatric intensive-care unit where she was reviewed by a consultant paediatric intensivist and a consultant paediatric surgeon. Her chest radiographs were reviewed by a consultant paediatric radiologist. All the clinicians agreed that her clinical course and findings were consistent with a diagnosis of a late-presenting congenital right-sided diaphragmatic hernia. However, on exploratory laparotomy the diaphragm was found to be intact. A CT scan then revealed multiple right-sided pulmonary abscesses (Figure 2). Next day she underwent a right middle lobe excision, from which she recovered without incident. No organisms were isolated either from the excised tissue or from blood cultures. The pathologist found no evidence of a bronchopleural fistula.

Figure 2.

Post-intubation chest radiograph

COMMENT

This case reveals the diagnostic difficulty occasionally posed by multiple air and air—fluid cavities on chest X-ray. In a previously well Caucasian toddler, the list of differential diagnoses should include an infected congenital cystic abnormality of the lung such as a bronchogenic cyst and cystic adenomatoid malformation², a primary pulmonary abscess secondary to a bacterial pneumonia, and a late-presenting congenital right-sided diaphragmatic hernia^3,4,5,6. Infected pulmonary air—fluid cavities developing in previously healthy or in congenitally abnormal lung tissue would normally be associated with a longer history of chest signs and symptoms in addition to the fever. Moreover, while the number and size of the cavities might increase, this would generally occur over a period of days, as commonly found in staphylococcal pneumonia^2,3. In this case, the time from the onset of respiratory symptoms was short and the course of the illness was rapid. Furthermore, the increase in the size and number of cavities, which occurred over a period of hours, was associated with institution of mechanical ventilation. At the time, the features seemed most consistent with insufflation of herniated bowel segments by air during the intubation procedure. The pathophysiology underlying the increase in size and number of fluid-filled cavities is unclear. It is possible that the lesions developed acutely after the child's admission to hospital and were the cause of the deterioration. Alternatively, the cavities might have been collapsed before the child was ventilated, and inflated by application of positive pressure.

In future, at our centre, all children who present with an intrathoracic mass on chest X-ray will have additional imaging to confirm and further define the pathology underlying the mass, especially when surgery is contemplated.