Question 1 of 10 · Order of Draw & Additive Interference

A nurse asks you to redraw a chemistry panel because the prior potassium resulted at 7.2 mEq/L on a patient with no cardiac or renal history. Reviewing the previous draw, you see the sequence was: gold SST, then lavender EDTA, then green lithium heparin. What is the most likely pre-analytical cause of the spurious hyperkalemia?