Quite a surprise! two thoracic cases on the same day.
Lung ca patients with "huge" malignant pleural effusions develop them for essentially two reasons: massive pleural spread or an obstructing lesion with an inability of the lung to expand. In both cases their prognosis is limited to a few weeks to months. Of course the way to determine which is the actual cause would be a full work-up including, bronchoscopy, CT and if in doubt a thoracoscopy. In the first case chest tube drainage with pleurodesis is the option of choice. The lung will expand and the adhesions will prevent the effusions from reaccumulating. In the second case, you can drain a huge volume of fluid and pour in any chemical agent you want and there will be no pleurodesis. The lung just can't expand so no adhesions can form. Moreover, drainage of these huge effusions doesn't even help the patient. By and large the mediastinum is not shifted and the patient doesn't benefit from the drainage of 3 liters. Considering the short prognosis of these patients, it is probably best to drain a few hundred cc whenever the mediastinum begins to shift, but in general they do not live longe enough to benefit from more than 2 or 3 taps. If by some chance, they appear to be doing well, then the Denver shunt is the way to drain off the excess- not drain them dry.