What is a potential risk if a large volume of pleural fluid is removed too rapidly during thoracentesis?

When a large volume of pleural fluid is removed too rapidly during thoracentesis, the risk of hypotension arises primarily due to the rapid shift in intrathoracic pressure and the potential for decreased venous return. The pleural cavity has a negative pressure that helps maintain venous return to the heart; removing a significant volume of fluid quickly can lead to sudden changes that might cause a drop in blood pressure. This can result in symptoms of hypotension, such as dizziness and fainting, which are important clinical considerations during the procedure.

While other complications like hemorrhage, atelectasis, and pneumothorax can occur during thoracentesis, they are not specifically associated with the rapid removal of fluid in the same way hypotension is. Hemorrhage is more related to bleeding from blood vessels, atelectasis could arise from lung collapse due to pressure changes, and pneumothorax occurs if air enters the pleural space. However, hypotension is a direct consequence of the abrupt changes in pressure and volume during the extraction of pleural fluid.