Abstract TP223: Then and Now: Temporal Evolution of a Mobile Stroke Unit

Introduction: Mobile stroke units (MSU) deliver pre-hospital intravenous thrombolysis (IVT) to patients with acute ischemic stroke. We hypothesize that time efficiencies with the MSU have improved over time with a dedicated team and experience. Methods: We reviewed 100 consecutive patients evaluated on the MSU from July-October 2014 (Group 1), compared to the most recent 100 patients April-July 2017 (Group 2). Collected data including initial NIHSS, patient age, door to CT performance time, door to CT read time, door to needle (DTN) time, alarm to IVT time, MSU scene arrival to departure time, and MSU alarm to back-in-service time were analyzed with rank sum test. Reported times are in medians with interquartile ranges (IQR). Results: Initial median NIHSS (6, IQR 3-12, p=0.78) and ages (65 years old, IQR 55-80, p=0.06) were comparable between the groups. Thrombolysis rate was 16% (n=16) in each cohort. Group 1’s DTN time declined from 31 to 23 minutes (p=0.01). Door to CT completion and read times were faster, at 17 versus 25 minutes (p<0.01), and 10 versus 13 minutes (p<0.01) for Group 2 and Group 1 respectively. MSU arrival to departure time also reduced from 43 to 30 minutes (p<0.01), with total MSU utilization time significantly improved from 88 minutes to 74 minutes (p<0.01) in Group 1 compared to Group 2. While alarm to door times extended from 20 minutes to 22 minutes in Group 2 (p=0.03), the alarm to IVT time was reduced from 55 minutes to 41 minutes (p<0.01). Conclusion: While the MSU geographical range has extended, the alarm to IVT time has shortened, reflecting a learned experience by a specialized team.