[Hemostasis and tests used to investigate it]

Abstract

Under physiological conditions, in healthy subjects, there is a perfect equilibrium between coagulation activation and inhibition systems. During a surgical operation, dysfunction of the coagulation activation system, responsible for haemorrhage, can be induced by the extent of the anatomical lesions or the pre-existence of a quantitative or qualitative platelet abnormality and/or one or several plasma clotting factors. In contrast, the postoperative period is dominated by the risk of thrombosis and this risk is increased in subjects with a deficit of a coagulation inhibitory protein. The patient's haemorrhagic and thrombotic risk must therefore be evaluated prior to any surgical procedure. The information obtained by clinical interview concerning the patient's personal and family history, combined with a few simple clotting tests generally allows prevention of haemorrhagic or thrombotic accidents.