Rebleeding after aneurysmal subarachnoid hemorrhage.

Rebleeding after initial aneurysmal subarachnoid hemorrhage (SAH) can have substantial impact on overall patient outcome. While older studies have suggested rebleeding occurs in about 4% of patients during the first day after initial aneurysmal bleed, these studies may have failed to capture very early rebleeds and, consequently, underestimated the impact of rebleeding. An electronic literature search was performed to identify English-language articles published or available for review from February 1975 through October 2010. A total of 43 articles (40 original research and 3 review articles) focused on rebleeding after initial aneurysmal SAH in humans were selected for review. Although most studies supported an incidence of rebleeding ≤4%, studies investigating ultra-early rebleeding reported bleeding within the first 24 h following aneurysmal SAH in as many as 9-17% of patients, with most cases occurring within 6 h of initial hemorrhage. Overall, studies investigating antifibrinolytic therapy to reduce rebleeding have failed to clearly demonstrate overall therapeutic benefit. Short-course antifibrinolytic therapy may have a role prior to initial aneurysm repair, although insufficient data are currently available.