Five-minute parameter of thromboelastometry is sufficient to detect thrombocytopenia and hypofibrinogenaemia in patients undergoing liver transplantation

Background. Early detection of coagulopathy is important to prevent bleeding during liver transplantation (LT). Rotation thromboelastometry (ROTEM (R)) provides the earliest parameter of clot amplitudes at 5 min (A5). We evaluated whether A5 correlates with platelet count (PLT) and fibrinogen concentration (Fib) and can predict thrombocytopenia and hypofibrinogenaemia in hypocoagulable patients undergoing living-donor LT (LDLT). Methods. A total of 3446 retrospective ROTEM (R) measurements, including 1139 EXTEM, 1182 INTEM, and 1125 FIBTEM, with simultaneously measured PLT and Fib, were analysed during LDLT in 239 patients. The correlations between A5 and maximum clot firmness (MCF) index, PLT, and Fib were calculated. Receiver operating characteristic analysis with area under the curve (AUC) was used to assess A5 thresholds predictive of PLT and Fib. Results. The median PLT was 47 000 mm(-3) and the median Fib was 100 mg dl(-1) during LDLT. The A5 parameters of EXTEM (A5(EXTEM)) and INTEM (A5(INTEM)) were highly correlated with MCF (r=0.96 and r=0.95, respectively), PLT (r=0.76 and r=0.77, respectively), and Fib (r=0.63 and r=0.64, respectively). A5 of FIBTEM (A5(FIBTEM)) was also correlated with MCF (r=0.91) and Fib (r=0.75). A5(EXTEM) thresholds of 15 and 19 mm predicted PLT<30 000 mm(-3) (AUC=0.90) and <50 000 mm(-3) (AUC=0.87), respectively, whereas A5(FIBTEM) 4 mm predicted Fib<100 mg dl(-1) (AUC=0.86). Biases from A5(EXTEM) and A5(FIBTEM) to their MCFs were 16.4 and 1.3 mm, respectively. Conclusions. A5 as an early variable of clot firmness is effective in detecting critically low PLT and Fib. A5 can therefore be a reliable fast index guiding transfusion therapy in hypocoagulable patients undergoing LDLT.