Lessons to be learned: a case study approach: Pseudohyperkalaemia due to thrombocytosis in a case of tube-ovarian abscess

The case described here is that of a 48-year-old lady who presented with ab dominal pain and fever; at a later stage she was found to have hyperkalaemi a of uncertain origin. Blood examination revealed there to be marked elevat ion of the platelets (thrombocytosis) on some occasions. It nas then realis ed that there was correlation between the platelet levels and serum potassi um values. During the clotting process the release of potassium from the in creased number of platelets caused the serum potassium to be elevated on ac count of an in vitro effect. The important point is that the raised serum p otassium levels were not due to an in vivo phenomenon and, therefore, the p atient did not need treatment for this; however, the presence of thrombocyt osis was itself a clue to the diagnosis which was eventually recognised as being due to an infection. At operation a tube-ovarian abscess was discover ed to be the cause of the problem.