Ok. Seven Years In Center HD. Slight Concussion Yesterday. Today

Ok. Seven years in center HD. Slight concussion yesterday. Today during treatment instead of using maintainence Heperin they flush my lines with saline every 30 minutes. Because of the additional saline they programmed my machine to take an extra 300 off. Near the end if treatment I cramped. Extremely bad cramping. Question: Can I take an Epsom Salt bath to relieve the pain? Do I need to worry about my magnesium levels or anything else?