This picture shows tubes being put into a centrifuge without their stoppers. Researchers found that doing so increased potassiums 47%. As a result, patients with low potassiums don't get treated because their samples are tested and reported to be normal. Patients with normal potassiums get treated for elevated potassium levels they don't have. Are your patients being mismanaged because of how their tubes are centrifuged? The Center for Phlebotomy Education has developed a potassium troubleshooting checklist to help your lab assure their potassium results are not being altered by those who draw and handle samples prior to testing.