Evaluation of the Minimum Concentration of Tranexamic Acid Required to Inhibit Fibrinolysis in a Population of Pregnant Women at Term.

Summary

Pregnancy induces a physiological change of hemostasis to a prothrombotic state : protein S decrease and increase of virtually all the clotting factors, in particular fibrinogen, von Willebrand factor and factor VIII. However, a state of hyperfibrinolysis may occur in the immediate postpartum period (especially after placental delivery), thereby promoting postpartum hemorrhage.

This state of hyperfibrinolysis is associated with the use of transfusions of blood products and the realization of hysterectomy.It is currently the most common etiology of maternal mortality in childbirth.There is an imperative to develop an efficient and reliable protocol for the management of this postpartum complication.

Tranexamic acid is an anti-fibrinolytic agent (like lysine) which acts by preventing the conversion of plasminogen to plasmin, by blocking the binding of plasminogen to the heavy chain of fibrin.The optimal dose of tranexamic acid enabling to inhibit fibrinolysis without increasing the complications rate remains to be defined. It is in this context that the investigators aim to evaluate, in an in-vitro model, the minimum dose of tranexamic acid required to inhibit fibrinolysis after activation of the latter by t-PA. The degree of fibrinolysis will be evaluated by thromboelastometry.

Conditions

• Hyperfibrinolysis

Interventions

PROCEDURE

Blood sampling (pregnant)

5.4 ml of venous blood will be taken during the delivery or the caesarian procedure, in addition to the standard of care blood sampling. This blood vial will be sent to the coagulation laboratory and all tests will be performed in vitro. The blood sample will be split in several aliquots. In each blood sample, fibrinolysis will be activated by the plasminogen tissular activator (tPA - concentration: 1066 UtPA/ml). Tranexamic acid will be added at increasing concentrations (2.5 microg/ml up to 40 microg/ml) to each sample and coagulation will be measured by two different tests: EXTEM and NATEM.

PROCEDURE

Blood sampling (non pregnant)

5.4 ml of venous blood will be taken. This blood vial will be sent to the coagulation laboratory and all tests will be performed in vitro. The blood sample will be split in several aliquots. In each blood sample, fibrinolysis will be activated by the plasminogen tissular activator (tPA - concentration: 1066 UtPA/ml). Tranexamic acid will be added at increasing concentrations (2.5 microg/ml up to 40 microg/ml) to each sample and coagulation will be measured by two different tests: EXTEM and NATEM.

Sponsors & Collaborators

• Brugmann University Hospital

  lead OTHER

Principal Investigators

• Philippe Van der Linden, MD · CHU Brugmann

• Arnaud Lechien, MD · CHU Brugmann

Study Design

Allocation

NON_RANDOMIZED

Purpose

PREVENTION

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Sex

FEMALE

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2015-11-30

Primary Completion

2016-04-30

Completion

2016-04-30

Countries

• Belgium

Study Locations