Volume-based haemostasis reserves in blood product free liver transplantations

Introduction: During liver transplantation, haemostasis is typically assessed by means of standard laboratory tests and viscoelastic tests, while dynamic monitoring of coagulation factor specific blood losses is an unusual, yet established approach. Aim: Our aim was to evaluate the volume-based haemostasis reserves in blood product free liver transplants in the first perioperative 48 hours, in association with the Child-Pugh score. Method: Data of 59 blood product free liver transplanted patients' coagulation factor levels, viscoelastic parameters and coagulation factor specific blood losses according to Gross methodological, baseline and 'coagulopathic' trigger levels were analysed. The haemostasis reserves were estimated according to the Child-Pugh classification. Laboratory tests and the calculation of haemostasis reserves were carried out before liver transplantation (T1), at the end of the surgery (T2) and also 12-24-48 hours postoperatively (T3-T4-T5). The viscoelastic tests were performed before liver transplantation (T1) and at the end of the surgery (T2). Results: Fibrinogen levels decreased by 1.2 g/L. Factor II, V, VII, X levels decreased by 26-40%. From T2 to T4, fibrinogen increased by 0.9 +/- 0.6 g/L over 24 h (p<0.001). Factor II, V, VII, X levels increased by 12-30% between T3 to T5 (p<0.001). The viscoelastic parameters remained in the normal range during liver transplantation (T1-T2). Haemostasis reserves decreased by 61% at the end of surgery (p<0.001), but reached 88% of the preoperative value on the second postoperative day. The initial reserves of Child B and C groups were 36-41% lower than Child A, nevertheless, these differences were not significant at 48 hours. Conclusion: The volume-based haemostasis approach supplements the standard laboratory and viscoelastic tests. This unusual approach dynamically indicates the actual reserve of haemostasis and shows the 'weakest link' within the system.