Abstract WP226: Bypassing Interhospital Transfers for Large Vessel Occlusions in the Era of Mobile Stroke Units

Abstract

Introduction: Mobile stroke units (MSU) provide prehospital intravenous thrombolysis (IVT) for patients with acute ischemic strokes and transport to thrombectomy-capable stroke centers. Door-in-door-out (DIDO) time is recognized as a measure of efficient workflow for interhospital transfer of patients for thrombectomy. We applied this measure to the MSU and compared with our Primary Stroke Center (PSC) transfer process in patients presenting with large vessel occlusions. Methods: We identified 50 patients who underwent thrombectomy for large vessel occlusion in a retrospective review. Mode of transport included MSU (n=18), conventional ambulance from PSC to Comprehensive Stroke Center (CSC) (n=19), or directly presenting to a CSC (n=13) in 2016-2017. Measured outcomes included times for PSC DIDO, MSU DIDO (MSU door to scene departure), door-to-CT, door-to-needle (DTN), and door-to-groin. Results: Among thrombectomy patients, IVT was more likely to be administered in a MSU (55.6%, n=10), than either a PSC (36.8%, n=7) or CSC (38.5%, n=5). Door-to-CT completed times were significantly lower in the MSU versus PSC (27 vs. 44 minutes, p<0.01). DTN times in MSU were significantly shorter than PSC DTN times (27 vs. 56 minutes, p<0.01), as were the median DTN times between CSC vs. PSC (27 vs. 56 minutes, p=0.09). Median DTN times comparing CSC vs. MSU were the same (27 minutes, p=0.33). DIDO time was reduced for MSU patients compared to PSC patients (27 vs. 87 minutes, p<0.01). Door-to-groin times for MSU patients compared to PSC patients was significantly reduced (97 minutes vs. 171 minutes, p<0.01). Door-to-groin times for CSC patients were comparable to MSU patients (100 minutes vs. 97 minutes, p=0.97). Conclusion: Advanced stroke systems of care which include a MSU are highly efficient in both IVT and transport for potential thrombectomy among patients presenting with large vessel occlusion. We introduce a concept of a MSU functioning as a mobile PSC, thus bypassing interhospital transfers.