Pleural hemorrhage in neonates on extracorporeal membrane oxygenation and after repair of congenital diaphragmatic hernia: imaging findings.

Abstract

The purpose of this study was to determine the frequency and range of radiographic and sonographic findings of clinically significant pleural hemorrhage in neonates who have had repair of a congenital diaphragmatic hernia and are being treated with extracorporeal membrane oxygenation (ECMO) for severe respiratory failure due to a combination of pulmonary hypoplasia and persistent pulmonary hypertension. Drainage and control of larger pleural hemorrhages and hemorrhagic pleural effusions, which may not be apparent clinically, can be essential to the successful completion of ECMO bypass support. The medical records, chest radiographs, and thoracic sonograms of 32 neonates with repaired congenital diaphragmatic hernia who were being treated with ECMO bypass were reviewed for radiographic and sonographic findings associated with significant pleural hemorrhage, defined as sufficient in amount to be recognizable by bedside imaging. Drainage of these hemorrhages was considered likely to result in improvement in the patient's clinical status and possibly to be essential to the patient's survival. The imaging findings most likely to reflect these large pleural hemorrhages were radiographic evidence of a rapid accumulation of pleural fluid or an atypical shift of mediastinal structures and sonographic demonstration of echogenic fluid in the pleural space. Nine patients had 11 episodes of pleural hemorrhage significant enough to produce recognizable radiographic and/or sonographic findings and to effect a change in clinical management. The imaging findings varied with the evolution of the usual thoracic changes after repair of the hernia, severity of pleural hemorrhage, and ability to drain the hemorrhage. Both tension and nontension hemothoraces and hemopneumothoraces were observed on portable chest radiographs before treatment. Atypical shift of mediastinal structures and/or rapid accumulation of pleural space fluid were the radiographic findings most suggestive of significant pleural hemorrhage and occurred in six of the nine patients. Sonography of the thorax confirmed pleural hemorrhage in eight patients and was nondiagnostic owing to overlying bandage material in one patient. The frequency of significant pleural hemorrhage in neonates with repaired congenital diaphragmatic hernia who were on ECMO bypass support was approximately 30%. The chest radiograph may be the initial indicator of large pleural hemorrhages in these patients. The radiographic findings can vary widely, from partial to complete opacification of the involved hemithorax and with varying degrees of contralateral mediastinal displacement. A shift in position of the ECMO cannulas may be the initial and only radiographic sign of pleural hemorrhage when both lungs are completely opaque and airless. Sonography is helpful in distinguishing hemothorax from pleural effusion. The combined radiographic and sonographic findings can be essential in deciding on appropriate therapeutic intervention.