Pleural Effusions and Pneumothoraces.

The pleural space is created by the parietal and visceral pleura that line the chest wall and the lung surface, respectively. Normally, only a small amount (0.3 mL/kg) of hypotonic fluid is present within the pleural space due to homeostatic balances in physiologic fluid production and absorption. Various infectious and noninfectious processes can lead to pathologic filling of the pleural space with fluid (effusion) or air (pneumothorax). Such pathologic changes create a true space that can interfere with normal lungmechanics and, in severe cases, cardiac function. Althoughmuch less common in pediatric than adult populations, pleural effusions and pneumothoraces in both groups can lead to substantial complications, resulting in significant morbidity and mortality if unrecognized or untreated. Overall, the cause of pleural effusions and pneumothoraces differs in children compared to adults. In adults, congestive heart failure (CHF) and malignancy account for a substantial number of pleural effusions, but these are uncommon causes in children. Infectious pleural effusions in the setting of pneumonia (parapneumonic effusions) remain the most common cause of effusions in both children and adults. Unlike the adult population, children experience spontaneous pneumothoracesmore often without underlying contributing pulmonary processes. The evolving role of imaging modalities and minimally invasive treatment approaches for pleural effusions and pneumothoraces has led to ongoing debate, AUTHOR DISCLOSURE Drs Cashen and Petersen have disclosed no financial relationships relevant to this article. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.