Evaluation of the BD vacutainer rapid serum tube on haemolysis markers in the emergency department

Aims Haemolysis is an important source of assay interference, especially in the Emergency Department (ED). A rapid-clotting serum tube, Becton-Dickinson (BD) Vacutainer Rapid Serum Tube (RST), was reported to reduce haemolysis rates compared to standard serum tubes. We evaluated the effect of RST on haemolysis markers compared with our current STAT testing tube, BD Vacutainer Plasma Separator Tube (PST). Methods Patients presenting to the ED over a 8-day period had an additional RST and BD Vacutainer non-gel heparin plasma tube collected. Blood was collected from 347 patients by trained nursing staff from an intravenous cannula using an adaptor device (Vacutainer Luer-Lok access device). All samples were then analysed for six haemolysis markers: haemolysis index, phosphate, magnesium, potassium, lactate dehydrogenase (LD), and aspartate aminotras-ferase (AST). Results We found 9% of samples were haemolysed (>0.5g/L free haemoglobin). Significant differences (p p 0.05) higher for phosphate and potassium and lower for LD. Discussion/conclusion RST tubes did not improve markers of haemolysis compared to plasma tubes.