Platelet reactivity in thromboelastometry. Revision of the FIBTEM test: a basic study

Abstract

This study aimed to investigate modifications to the FIBTEM test to better assess fibrinogen levels and the quality of fibrin polymerization in citrated blood using Multiplate impedance aggregometry to verify platelet inhibition. Blood samples from 26 healthy volunteers were subjected to thromboelastometry studies (EXTEM/FIBTEM tests) in accordance with the standard study protocol (cytochalasin D) and according to a modified protocol (synthetic IIbIIIa receptor antagonist vs. acetylsalicylic acid [ASA] + synthetic IIbIIIa receptor antagonist instead of cytochalasin D). Independent of thromboelastometry, Multiplate impedance aggregometry was used to assess the degree of restriction by the platelet blocked with the following treatments: (1) cytochalasin D, (2) synthetic IIbIIIa antagonist or (3) ASA + synthetic IIbIIIa antagonist to assess the aggregation response to activation with an agonist (ADP, collagen, thrombin receptor activating peptide-6 [TRAP-6], and arachidonic acid). Via aggregometry, cytochalasin D more weakly inhibited platelet aggregation than simultaneous administration of the -IIbIIIa receptor antagonist with ASA. However, total platelet aggregation inhibition was observed after simultaneous administration of cytochalasin D combined with a synthetic IIbIIIa receptor antagonist. In the thromboelastometry, a significant decrease of the A10, A20 and MCF parameters were observed in the EXTEM/FIBTEM tests after they were modified by the addition of a synthetic IIbIIIa receptor antagonist alone or in combination with ASA. In conclusion, in this Multiplate- and ROTEM-based laboratory approach, a two-way blockade (IIbIIIa-antagonist + cytochalasine D) was sufficient to completely inhibit procoagulant platelet function as observed by aggregometry and thromboelastometry.

Timing of major fracture care in polytrauma patients – An update on principles, parameters and strategies for 2020

“…Therefore, in addition to platelet counts, multiple dynamic test systems have been developed to rapidly identify these patients including the critical administration threshold (CAT), the assessment of blood consumption (ABC) score, and other dynamic platelet function tests (diamond of death) as identified by thrombelastography (TEG). These tests have been recommended in various studies (7,(113)(114)(115)(116)(117)(118), while other studies found no evidence for benefit using TEG and ROTEM (119).…”

FIBTEM as a predictor of intra- and postoperative blood loss in revision total hip arthroplasty

“…[11,12] FIBTEM is one of the ROTEM parameters and provides information about the change of fibrinolytic system, including fibrinogen concentration and fibrin polymerization. [13] In recent years, a number of articles have reported the usefulness of ROTEM as a POC device in numerous clinical situations such as emergency care, cardiovascular surgery, liver transplantation, trauma surgery, and septic disseminated intravascular coagulation. [11,14–17] FIBTEM is reported as an effective early predictor for massive bleeding and transfusion in orthopedic hip surgery and trauma patients.…”

The Dark Side of FIBTEM: Cytochalasin D

“…Other in vitro studies have demonstrated that "platelet noise" remains in the FIBTEM assay despite the addition of CytD. 3,4 This indicates that the MCF FIBTEM overestimates the "fibrinogen effect" on the clot strength because of both an undefined effect of the reagent on the plasmatic coagulation system and an incomplete inhibition of the platelet effect on the clot. However, this effect can be minimized by translating "dual platelet" inhibition from clinical into laboratory practice.…”