Evolving Role of Mobile Stroke Units Within the Prehospital Stroke Systems of Care

Pierre Fayad, MD; James C. Grotta, MD


Stroke. 2020;51(6):1637-1638. 

In This Article

Case Description Illustrating Complexity of Information and Data for Modeling Purposes

Fifty-nine-year-old man with sudden right middle cerebral artery syndrome at 09:15. EMS alert at 09:33 and was on-scene at 9:39. The location was 11 miles from MSU base, so MSU was not alerted (routine alerts within 8 miles of base). MSU was monitoring EMS radio while finishing another call and was added on at 10:00 after the EMS squad on-scene assessment. Major water main break had closed access to 3 Comprehensive Stroke Centers (CSCs) in the city, so MSU and EMS agreed to rendez-vous. EMS left the scene at 10:05 and the MSU–EMS rendez-vous occured at 10:11, 6.7 miles from the MSU base. NIHSS was 21 and computerized tomography showed dense right middle cerebral artery. tPA (tissue-type plasminogen activator) bolus was started at 10:30 (computerized tomography was repeated due to patient movement). Computerized tomographic angiography at 10:36 with right M1 occlusion. EVT team was alerted at one of 2 remaining open EVT centers at 10:39. ED arrival was at 10:54 and EVT started at 11:05, 92 minutes from alert and 110 minutes from onset.

It is hard to believe the MSU did not save substantial time for both tPA and EVT. If the MSU were not added to the call and EMS took patient to the nearest Primary Stroke Center, assuming door-to-needle 30+ minutes, the earliest possible tPA treatment would have been 10:55, with at least 25 minutes savings, and then would have to be transported to CSC for EVT with the process started sometime after 10:55. It would have been very unlikely that EVT would have been started at CSC before 11:05. If EMS had identified which CSC was open and took the patient directly there bypassing the Primary Stroke Center, they would have arrived at CSC at 10:30 at the very earliest (the same time the patient was already receiving tPA on the MSU), saving the entire 30+ minutes door-to-needle time at the CSC. Even if the patient skipped tPA, computerized tomographic angiography and EVT team alert upon arrival would still have been required, so it would have been very unlikely the patient would have been in the EVT suite before 11:05.