I Am Caring For A 76 Yr Old MS Patient

I am caring for a 76 yr old MS patient with an indwelling catheter. Recently she has had a lot of sediment in her urine resembling sand and scabs. She is also being treated for a UTI. Her catheter becomes blocked by the sediment and scabs blocking the catheter however she is still voiding outside of the catheter. Over a 7 hour time frame I have recorded 50ml of urine in her bag, but have changed her bed pads twice of saturation and scab like sediment. Is this a sign of kidney failure?