Are there practical treatments for pleural fluid buildup other than a drain tube?

My mom had a chest drain tube and abdominal drain tube put in about 2 weeks ago, and every second day a home care support worker has been draining anywhere from .5 to 1.5 liters of fluid from the abdomen and .5 to 1 liters from the chest tube with each visit.

I can give the details of my mom's colon cancer if necessary, but briefly she was operated on in Nov 2014 and had 2 rounds of chemo (5FU and some other stuff). She's 76 years old.

She is basically in palliative care at home at this point, but I'm wondering if there is any practical treatment for her pleural effusion that I should be advocating / insisting that she receive. I need to know if there are treatments for this - something that can reduce or prevent this fluid buildup. As far as I know, her cancer has not spread to her lungs so why she has this persistent fluid buildup in her chest (right side) I don't know. She isin't on any drugs to treat this fluid buildup, and no bronch-dilators.

I need to know the "standard of care" for someone in this situation above and beyond just draining the chest every 2 days. If there are effective ways to treat this situation, I need to know that so I can advocate for her that she receive this treatment.

Since my question deals with pleural effusion and draining, it may not be specific to colon cancer, so I don't know if this question is more appropriate for another forum here.