Blood clotting. Kidneys' dysfunction?

My father has been suffering from uric acid problem since 12years and a year ago he was diagnosed with a kidney disease.A month ago he had a swollen knee which was very painful but his uric acid levels were fine..He went through a knee wash out (arthoscopy) procedure only to find that there were blood clots in his knee and had no infection..Recently he started bleeding from his mouth and the pulmonologist asked him to go through a bronchoscopy and found out there were blood clots in his airways.He is on dialysis twice a week and his KFT panel seems fine however his haemoglobin is almost always at 6 and the doctors here keep on asking for more blood units.I see the problem here is of blood clots and it seems like it started before the dialysis begun,that is when his knee pain started..What could it be?? Should I consider seeing a haemotologist? Is it related to his kidneys' dysfunction?