If the pleural fluid is in both chest cavities at the same time, drain both sides if necessary. If the pleural fluid is unilateral, drainage of only one side is sufficient.
Hydrothorax is any fluid in the pleural cavity that is formed too quickly or absorbed too slowly by any number of factors. It produces a pleural effusion. Generally people with large amounts of pleural effusion are pumped 2 to 3 times a week until the pleural effusion disappears completely. The first draw should not exceed 700 ml, and subsequent draws should not exceed 1,000 ml. Avoid drawing too much fluid too quickly, either unilaterally or bilaterally.
Withdrawal of pleural effusion needs to be based on the condition of the patient to decide whether or not to drain bilaterally. If a pleural effusion is diagnosed, medical treatment needs to be sought as soon as possible to avoid worsening of the hydrothorax.