This study is designed to determine the causes of low sodium (salt) in the body fluids outside the cells for patients who have received a kidney transplant at the Mayo Clinic of Florida. The investigators will look at data collected on previous transplant patients at the Mayo Clinic to determine if the low sodium levels could be related to factors occurring in the course of surgery. The investigators hypothesize that the intravenous fluid used in the surgery, which is about half the concentration of normal saline, could contribute to the low sodium levels.