Spurious hemolysis does not influence the reliability of digoxin testing on Siemens RXL MAX and Roche Cobas e601.

Little information is available on the influence of spurious hemolysis on digoxin immunoassays. Seventeen consecutive, non-hemolyzed, sodium-heparin samples were divided in three aliquots. The first was immediately centrifuged and tested for hemolysis index (HI), as well as plasma digoxin on Siemens RXL MAX using the Siemens Dimension Flex and Roche Cobas e601 by electrochemiluminescent (ECLIA) technique. The second and third aliquots were subjected to mechanical hemolysis by aspirating the blood one and two times through a thin needle. The concentration of digoxin measured on Siemens RXL MAX was significantly decreased from aliquot #A, to aliquot #B (-4%), and aliquot #C (-6%), but in none of the hemolyzed specimens the 10% bias was exceeded. No significant variation was observed by measuring plasma digoxin on Roche Cobas. © 2012 by the Association of Clinical Scientists, Inc.