The balance between fibrinolytic activity and coagulation mechanisms seems to play an important role in the rebleeding of a subarachnoid hemorrhage (SAH) due to aneurysmatic rupture. In the present paper we describe our findings in a group of patients (n10) with S AH. The plasmatic levels of fibrinogen and their degradation products (FDP), APTT, prothrombin activity and factor XIII were determined within 72 hours of initial bleeding, or of eventual rebleeding. Factor XIII activity in the first bleeding was 82.1 ±4%, while the levels of FDP were 3.8±lmg/ml. In patients presenting rebleeding (n4), Factor XIII activity was 67.3±4.5% the day it manifested, which is significantly less than the values previously observed (p<0.01), while the FDP level was 4.1±2mg/ml. The decrease of factor XIII activity suggests an important role as regards clot stability in rupture location. It is also possible to attribute a rebleeding predictive value to its activity reduction.
factor XIII activity; subarachnoid hemorrhage; aneurysm rebleeding