its for all d docs on board,uro-surgeons or urologists...?

my mother is a kidney patient,aged 46,weight-48 kg, is having left kidney hydronephrosis because her left ureter is blocked from lower end and she is on PCN for left kidney.her urine output is 250 to 300 ml in 24 hrs.from left PCN and around 800 -1000 ml from fully wrking right kidney!so how can we come to know how much % her left kidney is working?and how this left partially working kidney can be revived fully?in a lot of probs..pls help!!thanx!