Hyperkalemia can occur in all the following except-: (A) Cushing syndrome, (B) Crush injuries, (C) Renal failure, (D) Intravascular haemolysis
Answer is A. The enhanced mineralocoicoid effect in Cushing syndrome is caused by occupation of the MR by the high concentration of coisol. Hypokalemia and metabolic alkalosis are more common in Cushing syndrome caused by ectopic ACTH production (90%) than in other causes of Cushing syndrome (10%) Ref Davidson 23rd edition pg 364