Jessica P.E. Davis, Patrick G. Northup, Stephen H. Caldwell, Nicolas M. Intagliata
Long thought to be hypocoagulable, new evidence suggests cirrhosis patients have 'rebalanced' coagulation in the setting of decreased synthesis of both pro- and anti-coagulant factors. Traditional testing like PT/INR reflects only the decreased synthesis of pro-coagulant factors and thus does not correspond to bleeding or clotting risk in this population. In this review, we discuss the use of viscoelastic testing (VET), an assay of global hemostasis in cirrhosis patients. We describe the technique and interpretation of commercially available VET and assess the application of VET in both transplant and non-transplant cirrhosis populations. VET largely correlates well with traditional testing including platelet count and fibrinogen level, however, is potentially less accurate in patients with low fibrinogen levels. VET may be useful in identifying patients at higher risk of hypercoagulable complications post-transplant and reflects changes in hemostasis in decompensated patients. While VET has been associated with decreased transfusion support in multiple studies, the lack of bleeding in patients who avoided prophylactic transfusion suggests a 'rescue' rather than prophylactic approach to transfusion may be ideal and further studies with a 'rescue' arm are needed. Additional prospective studies of VET should include clinically relevant endpoints of bleeding and thrombosis.
Key words. Coagulation., Cirrhosis., Thrombosis., Liver transplantation., Transfusion medicine.