Sonorheometry Device Thresholds in Liver Transplantation: An Observational Retrospective Study

Liver transplantation (LT) remains a potentially haemorrhagic procedure whose perioperative bleeding and transfusion could be better monitored using point-of-care devices. Quantra^® is a device based on sonorheometry to assess whole blood clot formation. Our aims were to describe Quantra^® parameters during LT and to study their correlations with standard laboratory parameters, and to determine Quantra^® cut-off values for thrombocytopenia, hypofibrinogenemia and coagulation factors' deficit.

In 34 patients undergoing LT, blood samples were collected before surgical incision, 15 min after the beginning of the anhepatic phase, and 15 min after arterial revascularization of the graft.

Clotting time (CT) was well correlated with prothrombin (PT) ratio and activated partial thromboplastin time (aPTT) ratio. Platelet contribution to clot stiffness (PCS) was correlated with platelets (ρ = 0.82, p < 0.001) and fibrinogen contribution clot stiffness (FCS) with fibrinogen (Fg) (ρ = 0.74, p < 0.001). CT predicted a PT ratio < 30% with an area under the curve (AUC) of 0.93 (95% CI 0.87-0.98; p < 0.001). PCS predicted a platelet count < 50 G/L with an AUC of 0.87 (95% CI 0.76-0.98, p < 0.001). FCS predicted a Fg < 1.0, 1.2 or 1.5 g/L, with an AUC of 0.86 (95% CI 0.77-094, p < 0.001), 0.82 (95% CI 0.74-0.91, p < 0.001) and 0.88 (95% CI 0.82-0.95, p < 0.001), respectively.

Quantra^® provides a rapid assessment of haemostasis during LT.