High levels of potassium after birth?

I started developing preeclampsia pretty early on..it escalated more towards the end and I was on bedrest. I had my baby at 37 weeks. Blood pressure went down the day after I had her and it's stayed normal. I started getting this warm flushing feeling in my arms and hands like then they run fluids through your iv..my doctor ran labs to check on my kidneys and said everything was normal except my potassium is high. She rushed me off the phone without explaining very much. She said the lasix I was taking to get fluid off would help. So has anyone dealt with high potassium?