Activation of Blood Coagulation After Aneurysmal Subarachnoid Hemorrhage: A Prospective Observational Trial of Rotational Thromboelastometry

OBJECTIVE: Aneurysmal subarachnoid hemorrhage (aSAH) has been reported to actuate blood coagulation. Rotational thromboelastometry (ROTEM) is a dynamic hemostatic test that can differentiate various coagulation abnormalities. For example, increased coagulation activity can be detected as a wider amplitude of tracing (maximal clot firmness [MCF]). ROTEM had not been used to evaluate coagulation changes after aSAH. We evaluated the ongoing coagulation process in patients with aSAH in a prospective, observational study to compare their ROTEM assay results with the control values obtained from patients undergoing clipping of nonruptured aneurysms. METHODS: ROTEM analyses were performed at 12, 24, 48, and 72 hours after the onset of aSAH and compared with the preoperative analyses from the control group. A total of 17 patients with aSAH treated in the intensive care unit and 16 control patients were enrolled. RESULTS: At 72 hours, EXTEM-MCF was significantly greater in patients with aSAH compared with the baseline values of the control group (68.0 mm [interquartile range (IQR), 66.0-71.0] versus 64.5 mm [IQR, 59.5-66.8]; P = 0.024). This was mainly due to increased fibrin formation and fibrin polymerization. The same comparison in the FIBTEM-MCF analysis yielded similar results (aSAH group, 23.0 mm [IQR, 19.0-25.0] vs. control group, 15.4 mm [IQR, 12.5-17.8], respectively; P = 0.001). CONCLUSIONS: Blood coagulation is activated at 72 hours after aSAH onset, which can be detected by ROTEM EXTEM-MCF analysis. Also, the FIBTEM-MCF was elevated, implying that the relative contribution of fibrin formation and fibrin polymerization is essential.