Abstract TP134: Effects of Strict Anesthesia Management in a Trial of Surgical Revascularization for Intracranial Atherosclerosis

Abstract

Introduction: Specific aspects of anesthesia management in clinical trials for cerebrovascular diseases have not been systematically addressed. As part of the EDAS Revascularization for Intracranial Atherosclerosis (ERSIAS) trial, we enforced strict management of hemodynamic parameters to prevent cerebral hypoperfusion during surgery. Methods: All patients enrolled in ERSIAS received intensive medical management, including antiplatelet therapy, even the day of surgery. Before every operation, a set of specific goals were discussed with the anesthesia team in a preoperative briefing, including strict regulation of SBP (lower limit = patient’s baseline when asymptomatic - upper limit = 200 mmHg), end-tidal CO 2 (ETCO 2 ) (35-45 mmHg while intubated), and fluid balance (even to positive 2L). Printed goals were posted by the anesthesia stations, anesthesia equipment alarms were set to the predetermined goals, and surgeons had continuous access to the patient’s vitals. Range-deviations lasting more than 5 minutes were recorded. Mannitol and high doses of steroids were avoided. Results: Fifty-two patients underwent EDAS surgery, four had ischemic strokes, and only one patient had perioperative ischemia. There was a significant reduction in the standard deviation variance of intraoperative SBP compared to the SBP during clinic visits (14.9 vs.23.9 mmHg p<0.01), reflecting a tighter SBP control during surgery. SBP goal deviations occurred in five cases, resulting in one perioperative stroke. In general, strokes were more common among patients with SBP goal deviations (20% vs.4.7%). Mean ETCO 2 was 38mmHg (SD=1, Range: 35-41 mmHg). There was only one ETCO 2 goal deviation with no clinical consequences. Fluid balance ranged between -0.25 and 3.1L, with a mean 1.2L (SD=0.6L). Mean estimated blood loss was 37 mL (SD=16, Range: 10-80mL). There were five deviations from the fluid protocol not associated with clinical complications. Conclusion: A goal-oriented pre-surgical briefing with anesthesia team and practical implementations, as discussed above, were effective in reducing hemodynamic variability in the ERSIAS trial. Rigorous SBP management is key in averting stroke during EDAS. Future trials should include standardized anesthesia protocols.