Test methods

The primary aim was to determine agreement and interchangeability of the TEG6S and TEG5000 platforms. We used the sampling methodology previously described by Lloyd-Donald et al. [1]. The TEG6S global haemostasis test provides four assays in one multi-channel cartridge, with each assay able to measure various components of the clotting process. We assessed: R time (min), K time (min), alpha angle (degrees), maximum amplitude (mm), and LY30% (%) on the standard citrated kaolin (CK) assay. Each of the TEG devices were calibrated appropriately with biological quality controls. Treating clinicians were blinded to the results of both TEG6S and TEG5000, however operators were neither blinded to either TEG results or clinical information of the patients. Blood was sampled from the patient’s arterial line by a single skilled TEG technician, as previously described [1]. As there is no need for controlled pipetting or prior manipulation of reagents, an unmetered amount of blood (~ 0.5 mL) was removed from the citrated tube and placed into each loaded TEG6S cartridge. All TEG6S assays were performed in automatically loaded microfluidic cartridges. TEG5000 assay sampling was performed manually using recalcification with 20 μl of calcium carbonate solution, and activation by kaolin, as per standard TEG protocol. Patient characteristics and reason for ICU admission was recorded.