Saturday, April 11, 2009

Saturday April 11, 2009
Regarding pleural effusions

Scenario:
67 yeear old male presented to ER with shortness of breath. There is significant opacification of left lateral lobe. Your dignosis is pleural effusion with underlying atelactasis. To acertain reasonable amount of fluid to tap (thoracentesis), what could be your next step?






Answer: Perform lateral decubitus films

CXRs done in the lateral decubitus position are more sensitive, and can pick up as little as 50 ml of fluid. Upright chest films need at least 300 ml of fluid to pick up pleural effusion consistent with blunting of costophrenic angles. If the fluid layer is more than 1 cm, there is enough of it to do a pleural tap. Lateral decubitus film may also help in revealing loculated pleural effusions, if any - which may require CT-guided thoracocentesis. 500 ml of pleural effusion is enough to show detectable clinical signs.