Abstract WP11: Decreased Intraprocedural End Tidal Carbon Dioxide Is Associated With Unfavorable Functional Outcome After Endovascular Intervention For Acute Ischemic Stroke

Abstract

Introduction: Patientsundergoing endovascular intervention for acute stroke may have better outcomeswhen managed with conscious sedation (CS) instead of general anesthesia (GA). Previous investigations have not elucidated aclear mechanism for this observation. Hypothesis: Wehypothesize that decreased intraprocedural blood pressure and decreased end tidal CO2 would be associated with worsened functional outcomes at 90 days. Methods: Consecutive patients undergoing stroke interventions between August 2007 and December 2010 were identified from a prospective database. Clinical data was then extracted by retrospective chart review. Outcomes were stratified according to 90 day modified Rankin Scale (mRS), with scores of 0-3 designated as favorable and 4-6 as unfavorable. Variables significantly associated with outcome in univariate analysis were also examined in multivariate analysis, controlling for well-established predictors of functional outcome: age, medical comorbidities, TICI score, and NIH stroke scale score. Results: Of the 106 patients identified, 86 had complete medical and anesthetic records and could be included in the study. None of the measured parameters, including the absolute BP, the absolute decrease in BP, and the relative decrease in BP were associated with functional outcome at 90 days. On the other hand, end tidal carbon dioxide (ETCO2) at 60 min and 90 min was significantly associated with outcome in both univariate and multivariate analysis, controlling for other well-established predictors of functional outcome. Conclusion: Intraprocedural hypocapnia was associated with unfavorable functional outcomes at 3 months, whereas intraprocedural blood pressure was not related to functional outcome. This finding suggests that intraprocedural hypocapnia, rather than the hemodynamic effects of anesthesia, may account for the differences in outcome between GA and CS patients.