Abstract TP239: Initial Results From a Community Emergency Medical System Based Bypass Protocol Using Rapid Arterial Occlusion Scale to Screen for Emergent Large Vessel Occlusion

Abstract

Introduction: Although mechanical thrombectomy (MT) is the standard of care for patients with acute ischemic stroke due to emergent large vessel occlusion (ELVO), few patients remain eligible for MT due to pre-hospital delays and presentation to non-MT capable hospitals. Emergence of in field screening tools have allowed EMS to reliably identify patients with likely ELVO, thus facilitating their direct triage to MT capable hospitals for prompt thrombectomy. Methods: In collaboration with the Peninsulas EMS Council (PEMS), we implemented a community based pilot program in the Hampton Roads region of Southeastern Virginia to identify patients with ELVO by utilizing the Rapid Arterial oCclusion Evaluation (RACE) scale, a validated in field screening tool. Under this protocol, since March 1 st , 2017, patients with a RACE score of ≥ 5, presenting within 6 hours of last known well would be transported directly to a Comprehensive Stroke Center (CSC) rather than a Primary Stroke Center (PSC), provided the bypass does not prolong the trip by more than 15 minutes. We present the initial results of this study including iv tPA and MT treatment rates, time metrics, and patient outcomes, in comparison to the pre-RACE protocol data. Results: Between March 1 st and June 30 th , 2017, of the 75 brain attacks received in our CSC, 45 patients were screened using the RACE scale by the EMS. 30 patients scored ≥ 5 on the RACE scale (RACE +) and 21 of those bypassed PSCs on their way. RACE + patients had a higher median NIHSS (16 vs. 6, p < .0 5 ), and ischemic strokes (70% vs. 58%), compared to the non-RACE + patients in the preceding 4 months. Improved time metrics (median) were observed for symptom onset to arrival (54 min vs. 81 min), arrival to CT (8.5 min vs. 12 min, p < .05), DTN (36 min vs. 47 min), DTG (94 min vs. 105 min), and arrival to recanalization with MT (142 min vs. 185 min). IV tPA (27% vs. 11%) and MT treatments rates (33% vs. 11%) with TICI ≥ 2b (90% vs. 77%) were higher in the RACE + patients compared to the non-RACE + cohort. Conslusion: Our pilot program employing RACE as an in field screening tool for ELVO and using it to bypass PSCs in favor of CSCs is feasible in the community setting, and demonstrates improved metrics in key domains known to be associated with better outcomes for these patients.