I had a patient who's morning labs came back with K 5.0 and Na 127. The patient had been getting D5 1/2 NS all night at 125 cc/hr and urine output was about 30-40 cc/hr. I was concerned for fluid overload and suspected the fluids might've been responsible for the low sodium as well. The resident rounding wrote for lasix 40 mg IVP as well as fluids to be changed to D5 NS at 75 cc/hr. I thought it was okay at first, but now that I'm home I can't stop wondering what that might do to his sodium. I can't find any concrete numbers on how strong of an effect lasix has on sodium. Any thoughts, resources, ideas?