Initial and recurrent bleeding are the major causes of death following subarachnoid hemorrhage.

BACKGROUND AND PURPOSE The goal of this study was to determine the causes of mortality and morbidity after subarachnoid hemorrhage. METHODS We identified all first-ever spontaneous subarachnoid hemorrhages that occurred in the nearly 1.3 million population of greater Cincinnati during 1988. RESULTS Thirty-day mortality for subarachnoid hemorrhage was 45% (36 of 80 cases). Of the 36 deaths, 22 (61%) died within 2 days of onset; 21 of these deaths were due to the initial hemorrhage, and one death was due to rebleeding documented by computer tomography. Nine of the remaining 14 deaths after day 2 were caused by the initial hemorrhage (2 cases) or rebleeding (7 cases). Volume of subarachnoid hemorrhage was a powerful predictor of 30-day morality (P = .0001). Only 3 of the 29 patients with a volume of subarachnoid hemorrhage of 15 cm3 or less died before 30 days. Two of these 3 patients died from documented rebleeding; the third had 87 cm3 of additional intraventricular hemorrhage. Delayed arterial vasospasm contributed to only 2 of all 36 deaths. CONCLUSIONS Most deaths after subarachnoid hemorrhage occur very rapidly and are due to the initial hemorrhage. Rebleeding is the most important preventable cause of death in hospitalized patients. In a large representative metropolitan population, delayed arterial vasospasm plays a very minor role in mortality caused by subarachnoid hemorrhage.