Activation of blood coagulation after aneurysmal subarachnoid haemorrhage: a prospective observational trial by rotational thromboelastometry (ROTEM®).

OBJECTIVES: Aneurysmal subarachnoid haemorrhage (aSAH) is reported to actuate blood coagulation. Rotational thromboelastometry (ROTEM®) is a dynamic haemostatic 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]). Previously, ROTEM® has not been used to evaluate coagulation changes after aSAH. The aim of this prospective, observational study was to evaluate the on-going coagulation process in patients with aSAH by comparing their ROTEM assay results to the control values obtained from patients undergoing clipping of non-ruptured aneurysms.

METHODS: ROTEM® analyses were performed at 12, 24, 48, and 72 hours after onset of aSAH and were compared with preoperative analyses of the control group. In total, 17 aSAH treated in the intensive care unit and 16 control patients were enrolled.

RESULTS: At 72 hours, EXTEM-MCF was significantly higher in aSAH patients compared with the baseline value of the control group (68.0 mm [interquartile range, {IQR} 66.0-71.0 mm] vs. 64.5 mm [IQR, 59.5-66.8 mm]; P = 0.024). This was mainly due to increased fibrin formation and fibrin polymerisation as the same comparison in FIBTEM-MCF analysis yielded similar results (23.0 mm [IQR, 19.0-25.0 mm] vs. 15.4 mm [IQR, 12.5-17.8 mm], respectively; P=0.001).

CONCLUSIONS: Blood coagulation is activated at 72 hours after onset of aSAH, which can be detected by ROTEM® EXTEM-MCF analysis. At the same time, FIBTEM-MCF was elevated, implying that relative contribution of fibrin formation and fibrin polymerisation are essential.