Aneurysmal rebleeding: a preliminary report from the Cooperative Aneurysm Study.

It is generally considered that the peak incidence of rebleeding after aneurysmal subarachnoid hemorrhage is at the end of the 1st or the beginning of the 2nd week after the initial rupture. However, in a series of 2265 patients admitted within 3 days of their first subarachnoid hemorrhage, the peak of rebleeding occurred on the same day as the initial hemorrhage and there was no later peak. These data suggest that new management strategies for minimizing rebleeding must be considered for patients admitted soon after aneurysm rupture.