Thank you for your question.
Raised CPK can have many causes, these include injury to the muscles, high fever
, inflammation of the muscles called as myositis
, McArdle's disease also causes high CPK levels.
In any condition the levels of CPK can fluctuate and since she was dialysed so the CPK must have been removed from the blood via dialysis
so that could be the reason why it is not raised anymore.
Such a high CPK does require further testing such as a muscle biopsy
etc to determine exaclty whats causing it and then to treat the condition accordingly.