A Practical Guide to Haemostasis

Global Assays of Haemostasis:


Haemostasis is a complex process that is dependent upon the interaction of many cellular and plasma components. Many tests exist that allow us to dissect different aspects of Haemostasis and many of these are covered in this website. However, many of these tests look at haemostasis in isolation, often using non-physiological activators, frequently in platelet poor plasma and commonly are based on the formation of a fibrin clot.  There is, therefore, increasing interest in Global Tests of Haemostasis both in the laboratory and in the near-patient setting that allows an analysis of the overall haemostatic profile. The aim of such tests is to identify individuals who may be at risk of bleeding or thrombosis or in some cases to more effectively monitor/manage their treatment. 

These tests are covered in detail through but include:

Test Comments
ROTEM Viscoelastic Haemostatic Assays performed on whole blood and which allow an analysis of clot formation, clot elasticity development and fibrinolysis process in real time.  Increasingly these are employed as Point-of-Care devices.
Modification of the tests allow the clotting pathways to be analysed in detail.
ETP Endogenous Thrombin Potential which measures endogenous Thrombin generation.
Global Thrombosis Test The Global Thrombosis Test [GTT] is a Point-of-Care test of Platelet function, Thrombin generation and Thrombolytic activity. This in vitro test evaluates the formation of a shear-induced thrombus and its subsequent lysis [Thrombolysis] under physiological conditions using non-anticoagulated blood samples.

Click HERE for further information on the role of this test in monitoring endogenous thrombolysis.
OHP  Assay The Overall Haemostatic Potential [OHP] assay is a global assay of Fibrin generation and Fibrinolysis and which has been evaluated in a number of clinical situations.  The Test involves the generation of a Fibrin Time Curve in which the generation of Fibrin and its subsequent lysis is measured by changes in absorbance at 405nm.

The Coagulation Inhibitor Potential (CIP) assay is a development of the Overall Haemostatic Potential [OHP] assay in which a Pentasaccharide is added to the plasma sample to activate Antithrombin and so increase the sensitivity of the assay to functional abnormalities/deficiencies of Antithrombin and in addition Protac is included which activates Protein C to activated Protein C [APC].
CIP Assay
ReoRox The ReoRox G2® assay is a viscoelastic-based system that measures the viscoelastic properties of whole blood using free oscillation.