She is feeling weak after dialysis because they are removing too much fluid from her body during dialysis. Discuss with your doctor to see if removing less fluid or not removing fluid from her body will prevent her from feeling weak. In disease of kidney caused by pain killers used in rheumatoid arthritis, patient tend to pass a lot of urine compared to other patients and hence many a time only dialysis is required and little or no extra fluid needs to be removed during dialysis. If your mom has pain still discuss with your doctor if she will benefit from steroid and leflunomide. The chance of your mom recovering is high if the creatinine increase is recent. However for predicting chances of improvement more information is required. Discuss with your doctor if she will need a renal biopsy in the near future. It can predict recovery better than other tests. However if the kidneys are severely damaged and small biopsy is dangerous and treatment has to done without kidney biopsy. Wishing fast recovery for your mom. Hope the information helps.