Abstract Body: Background and Purpose: Early and accurate identification of large vessel occlusion (LVO) stroke is critical to optimizing patient outcomes, particularly in timely endovascular thrombectomy (EVT). Despite existing protocols, challenges remain in ensuring that patients are rapidly identified and appropriately transferred to neurovascular centers. This study aims to review suspected LVO stroke cases to identify patterns in emergency medical services (EMS) activation for transport and subsequent transfer decisions by considering a stand-by EMS approach.
Methods: A retrospective chart review was conducted for all patients with suspected LVO stroke presenting to the Emergency Department (ED) within 24 hours of last known normal and with the National Institute of Stroke Scale (NIHSS) score of greater than 6 and modified Rankin Scale (mRS) of 0-1 from June 2023 to June 2024.
Results: Of 48 cases initially identified for potential transfer to a thrombectomy center, only 16 cases had a final diagnosis of LVO stroke. Of these, only 43% (N=7) or 14.5% of the original number of cases were transferred for thrombectomy. Reasons for non-transfer for the nine cases with LVO included no meaningful recovery due to stroke severity, perfusion study mismatch, and the area of clot being too distal for thrombectomy. The median time from patient arrival to ED to EMS activation for transport was 39 minutes. The average EMS arrival time is 32 minutes. For the 32 non-LVO cases. 43% (N=14) did not have an LVO on imaging with cortical signs and symptoms, 38% (N=12) had an intracranial hemorrhage, and 19% (N=6) were stroke mimics. Based on these results, pre-ordering EMS based on initial assessment (NIHSS and mRS) would result in overcalling EMS 85% of the time.
Conclusion: While re-ordering EMS based on initial assessment (NIHSS, mRS, and opinion of tele-neurologist) has the potential to greatly improve transfer times for patients with LVO stroke, it is not feasible based on the large number of misclassified cases. Additional ED screening tools are required.