Abstract TP424: Timing Of Deep Vein Thrombosis Formation After Aneurysmal Subarachnoid Hemorrhage
Background: Deep vein thrombosis (DVT) is a common complication following aneurysmal subarachnoid hemorrhage (aSAH). The time period of greatest risk of developing DVT after aSAH is not known. Early DVT detection may enable earlier treatment and prevent progression to symptomatic DVT or pulmonary embolism (PE). We tested the hypothesis that DVT most often occurs during the period of highest risk of delayed cerebral ischemia (3-14 days post-rupture).
Methods: We performed a retrospective review of 154 patients admitted to the OHSU NeuroICU with aSAH between April 2008 and April 2010. 121 patients received periodic screening lower extremity ultrasounds, typically twice weekly, and prophylaxis with sequential compression devices (SCDs) but no chemoprophylaxis such as heparin. The remaining 33 patients did not receive screening studies due to withdrawal of care or attending physician preference.
Results: 26 of 121 patients (21.5%) who received ultrasound screening developed DVT after aneurysm rupture. 3 of 26 patients (2.5% of the total screened population) had symptomatic DVTs, as defined by documented clinical suspicion in chart notes, and 1 of these developed PE. DVTs were significantly more likely to be detected 3-14 days post-bleed (χ-square, p < 0.0006) and were detected on average 12.0 +/- 6.8 days (median 10 days) after aneurysm rupture. Because DVTs did not necessarily occur on the day of detection, we calculated the period at risk by determining the day of the last known ultrasound without DVT, or by the day of aneurysm rupture if the DVT was detected on the first screening scan. The average day beginning the period at risk was 5.7 +/- 6.7 days (median 2 days) after aneurysm rupture. The average number of days within the period of risk was 6.3 +/- 3.6 days (median 6.5 days).
Conclusion: DVTs are significantly more likely to be detected 3-14 days after aneurysm rupture. Repeated screening allows for evaluation of the period of highest risk for developing DVT. The data suggest that this period occurs between 5.7 and 12.0 days on average (median 2-10 days) following aneurysm rupture. Prospective studies are needed to determine whether chemoprophylaxis targeted to this time window reduces DVT incidence while minimizing bleeding risk.
- © 2012 by American Heart Association, Inc.