Abstract 32: 'Rendezvous System' for Broadening a Mobile Stroke Unit Catchment Area

Purpose: Mobile Stroke Units (MSU) deliver acute stroke treatment on-scene in coordination with Emergency Medical Services (EMS) prior to transport to a stroke center. One criticism is the limited range of a single MSU. The Houston MSU is the only one in the U.S. using a rendezvous system with EMS to expand its range. Methods: In addition to direct 911 dispatch of our MSU directly to the scene for tPA eligible patients within our “catchment” area (8 miles), we asked more distant EMS units to notify the MSU and also monitored EMS radio communication to identify eligible patients. For these “distant” patients, the MSU meets the EMS unit enroute to the stroke center and treats the patient at that intermediate location (usually a parking lot). The distribution of the distance from MSU base station to site of stroke and time from alert to tPA bolus were compared between patients treated on scene and by rendezvous using Wilcoxon rank sum test. Results: From August 18, 2014 to July 20, 2018, 290 acute ischemic stroke patients were treated with tPA on our MSU. Of these, 140 (48.3%) were treated on scene by direct 911 dispatch, with a median of 7 miles (IQR 5 miles) from MSU base station. 150 (51.7%) patients were treated by rendezvous. They had their strokes a median of 13 miles from base (IQR 6 miles) (p Conclusion: A “rendezvous system” significantly expands the range of operations for a MSU in an urban area, doubling the number of patients treated, without incurring delay. This approach might be even more useful in rural areas.