Rebleeding, secondary ischemia, and timing of operation in patients with subarachnoid hemorrhage

Objective: To assess the time course of secondary ischemia and first reblee ding and the relation between the timing of operation and the time course o f secondary ischemia in a consecutive series of patients with aneurysmal su barachnoid hemorrhage (SAH), Methods: Life table methods were used to asses s the daily rates of ischemia and of rebleeding on day 0, day 1 to 3, day 4 to 10, day 11 to 14, and day 15 to 21. The authors compared the time cours e of secondary ischemia between patients operated within 4 days of SAH and those operated after 10 days. Results: Of 346 patients included, 220 were o perated, 131 within 4 days and 74 after 10 days. The rebleed rate was highe st on the day of the initial hemorrhage, then diminished, and increased sli ghtly again during the second week. The rate of secondary ischemia was high est on day 4, diminished after day 10, but peaked again from day 14 to 18 f or patients who were operated later than 10 days after aneurysmal rupture. The peak rate of ischemia was much higher after early than after late opera tion. Although patients with early operation were in a better clinical cond ition on admission, with a relatively low risk of secondary ischemia, the o verall rate of secondary ischemia was as high as in patients with delayed o peration. From day 11 to 21 the rebleed rate was higher than the rate of se condary ischemia. Conclusions: These results indicate that operation is a r isk factor for ischemia, especially when performed early. If operation is p ostponed, it should be planned soon after day 10, because of the relatively high rebleed rate from day 11 to 21.