Fluid around lung

My mother aged 72 had a leg bypass 7 months ago,after which was put on warfarin. her leg has been very large and full of fluid since. water tablets didn't help at all, she recently became a little breathless with a bit of a cough. Then developed a bad cough and chest infection which was treated with antibiotics, the breathlessness got worse with a pain in her side. then she coughed up blood which was investigated with an xray  and was told she had fluid on the lung.She is now waiting to have a biopsy, to find the cause of the fluid, she has had about 3 litre drained off because she was in distress. warfarin had to be stopped for this so having to wait for levels to drop. She is very unwell and not eating but her stomach is still big think she may have fluid there too. when the fluid is drained it is the colour of red wine. Could this fluid be connected to the build up in her leg. Have you any idea what the cause may be. THANKS

[National Jewish]

Pulmonary embolism (PE) is a blood clot in an artery of the lungs.  This could be the cause of your mother