WHAT THE NEUROSURGEON NEEDS TO KNOW ABOUT THE COAGULATION SYSTEM

Intracranial surgery is often complicated by thromboembolic events inc luding the life-threatening pulmonary embolism. After head trauma and in patients with brain tumors disseminated intravascular coagulation ( DIC) can occur, characterized by the triggering of the coagulation cas cade and the depletion of coagulation factors which ultimately leads t o bleeding. The identification of patients at high risk as well as the early diagnosis of hemostatic problems uses routine laboratory parame ters such as partial thromboplastin time and prothrombin time reflecti ng the intrinsic and the extrinsic pathway of the coagulation respecti vely Thrombin antithrombin III complexes (TAT) and prothrombin fragmen t 1 + 2 (F1 + 2) are further indicators of an activation of the coagul ation whereas fibrinogen degradation products (FDP) refer to the fibri nolytic system. The basic principles of coagulation and fibrinolysis a re summarized as well as the changes of laboratory parameters accompan ying DIG, hypercoagulability and hyperfibrinolysis. (C) 1997 by Elsevi er Science Inc.