Diseases of the pleura

In this review, three aspects of pleural disease are discussed. Although it was thought for many years that the origin of pleural fluid was the capillaries in the parietal or visceral pleura, recent evidence suggests that in many cases the origin of pleural fluid is the interstitial space of the lung. The interstitial space of the lung appears to be the source of the pleural fluid in patients who have congestive heart failure, parapneumonic effusions, pulmonary embolism, and lung transplants. The Hantavirus pulmonary syndrome is characterized by rapidly progressive, noncardiogenic pulmonary edema in relatively young, previously healthy individuals. The mortality rate with this syndrome is approximately 60%, and at autopsy most patients have large pleural effusions. Patients after lung transplantation frequently have profuse drainage from their chest tubes because most of the fluid that enters the lung must exit through the pleural space. The incidence of pleural effusion is very high in patients who have a complication of their lung transplantation, but the pleural fluid findings in patients after lung transplantation have not been well studied. Similarly, virtually all patients who undergo liver transplantation have a right-sided pleural effusion. The effusion usually reaches its maximum size around the third postoperative day. If the effusion increases in size after this time, serious complications should be suspected. The approach to pleural diseases has been altered with the advent of videothoracoscopy. Videothoracoscopy should be considered in patients who have undiagnosed pleural effusions and are not improving; in patients who have had recurrent pneumothorax, or a spontaneous pneumothorax with a persistent airleak or unexpanded lung; or in patients who have a traumatic hemothorax with clotted blood.