As our patients have been normokalemic at the start of the therapy and have developed hyperkalemia after 4 h, the most common reasons for the development of hyperkalemia can be ruled out: chronic kidney disease (which has been either absent or mild in our patients), pharmacological therapy like potassium substitution (not present, AA used during therapy does not contain potassium), or Renin-Angiotensin-System Blockade (not present). Here, REN is linked to chronic kidney disease.