Discrepant Potassium Results.

Abstract

A 70-year-old male patient called our laboratory to complain about an increased potassium result of 6.1 mmol/L, based on which his doctor advised him to go to the nearest emergency department (ED).2 He stated that he was scared and immediately went to an ED despite lacking chest pain, nausea, or dizziness. However, the ED laboratory obtained a potassium result of 4.7 mmol/L, and he was sent home. He questioned the high potassium result obtained from our laboratory, which caused him distress and an unnecessary ED visit. After receiving the patient's complaint, we retrieved the original serum sample collected in a BD Vacutainer® serum separator tube (SST™, Gold Top) for comprehensive metabolic panel (CMP) and visually examined it for hemolysis. The serum sample did not appear to be hemolyzed. In our laboratory, we use an indirect ion selective electrode (ISE) method on the Roche (Roche Diagnostics) Cobas 6000 automated chemistry analyzer to measure potassium. The original result of 6.1 mmol/L on the sample was above the critical call limit of 6.0 mmol/L for our laboratory and was confirmed by repeat testing before it was reported and called to the ordering physician. Quality control (QC) data was in range, indicating a normal working analytical process. As part of the investigation, we …