Point-of-care viscoelastic assay devices (rotational thromboelastometry and thromboelastography): a primer for surgeons.

VE assays are used most commonly during orthotopic liver transplantation, trauma, postpartum haemorrhage and cardiac surgery. Although the evidence is not overwhelming, we have identified recurrent themes where VE assays seem to be beneficial. VE assay use, especially when incorporated into an algorithm, appears to reduce blood product administration which in turn reduces cost and potential adverse events. They are quicker than SLTs and they can detect hyperfibrinolysis, the hallmark of coagulopathy, via in vivo clot analyses which SLTs are unable to do. Ultimately more randomized controlled trials are required.