Lung Cancer, Pleural catheter not draining - 1268927

Hello,

I got some unusual responses from my dad's clinical team and I am not sure what to do.
He had a pleural catheter inserted in early January 2015, after what had been a stable effusion, grew very large and caused a partial collapse of his lung. He went from draining 500-700 ml daily to 150-200 ml currently. His Lung is re-expanding and he has recently began feeling better. He has stage 4 adencarcinoma and is currently on Tarceva. However his Onc has recently been seeing very slight signs that tumor resistance is happening.

His catheter has stopped working and in the past has had to be flushed with saline. We contacted his pulmonologist office on a Monday and were told on Thursday no appointments were available for 2 more weeks. And that unless he is having breathing trouble it is ok that the catheter is not draining. We are not sure if this advice came from his pulmonologist or if this is a nurses advice. We are concerned that waiting for two weeks (it will actually have been three weeks from the day the catheter stopped draining) could cause damage to his already weakend left lung.

Question: A 65 yr old man with malignant pleural effussion, a recent history of partially collapsed lung and signs of resistance to his current treatment. He drains around 1,000 ML a week, how long can he wait to drain the effusion before it causes damage?