Comparison between thrombelastography and thromboelastometry in hyperfibrinolysis detection during adult liver transplantation.

Background: Hyperfibrinolysis is one of the main causes of non-surgical bleeding during liver transplantation (LT). Viscoelastic haemostatic assays, including thromboelastometry (ROTEM(®)) and thrombelastography (TEG(®)), can detect hyperfibrinolysis at the bedside. No study has yet demonstrated which device or assay is more suitable for detecting hyperfibrinolysis.
Methods: This prospective observational study compared ROTEM(®) and TEG(®) in isolated adult LT. ROTEM(®) (EXTEM(®) [tissue factor activation], FIBTEM(®) [tissue factor activation with platelet inhibition], and APTEM(®) [tissue factor activation with tranexamic acid/aprotinin]) and TEG(®) (kaolin-TEG(®)) were simultaneously performed using arterial blood samples at eight time-points during LT: induction of general anaesthesia, 60 min after skin incision, 10 and 45 min after portal vein clamp, 15 min before graft reperfusion, and five, 30, and 90 min after graft reperfusion. Hyperfibrinolysis was identified per the manufacturers' definitions (maximum lysis >15% in ROTEM(®) or Lysis30>8% in TEG(®)) and confirmed with APTEM(®); incidence was compared between assays McNemar's test.
Results: Among 296 possible measurement points from 376 consecutive LT recipients, 250 underwent final analysis: 46 measurement points were excluded because of missing assays or flat line. Hyperfibrinolysis was confirmed at 89 (36%) of 250 measurement points: FIBTEM(®), EXTEM(®), and kaolin-TEG(®) detected 84 (94%), 41 (46%), and 21 (24%) hyperfibrinolysis, respectively. These hyperfibrinolysis detection rates significantly differed from each other (P<0.001).
Conclusions: Tissue factor-triggered ROTEM(®) tests were more sensitive than contact-activated k-TEG(®) in identifying hyperfibrinolysis in LT patients. Inhibition of platelet-fibrin interaction in FIBTEM(®) enhanced sensitivity to hyperfibrinolysis detection compared with EXTEM(®).
(© The Author 2016. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)