Characterizing Strokes and Stroke Mimics Transported by Helicopter Emergency Medical Services

Objective: Stroke is the leading cause of disability in the United States with most of these patients being transported by emergency medical services. These providers are the first medical point of contact and must be able to rapidly and accurately identify stroke and transport these patients to the appropriate facilities for treatment. There are many conditions that have similar presentations to stroke and can be mistakenly identified as potential strokes, thereby affecting the initial prehospital triage. Methods: A retrospective observational study examined patients with suspected strokes transported to a single comprehensive stroke center (CSC) by a helicopter emergency medical service (HEMS) agency from 2007 through 2013. Final diagnosis was extracted from the Get with the Guidelines (GWTG) database and hospital discharge diagnosis for those not included in the database. Frequencies of discharge diagnosis were calculated and then stratified into interfacility vs. scene transfers. Results: In this study 6,243 patients were transported: 3,376 patients were screened as potential strokes, of which 2,527 had a final diagnosis of stroke (2,242 ischemic stroke and 285 transient ischemic attack), 166 had intracranial hemorrhage, and 655 were stroke mimics. Stroke mimics were more common among scene transfers (223, 32%) than among interfacility transfers (432, 16%). Conclusions: In our study approximately 20% of potential stroke patients transported via HEMS were mimics. Identifying the need for CSC resources can be an important factor in creating a prehospital triage tool to facilitate patient transport to an appropriate health care facility.