UMEM Educational Pearls

Category: Neurology

Title: Phantoms in EMS

Keywords: Stroke, EMS, prehospital care, tPA, emergency medical services, fibrinolysis (PubMed Search)

Posted: 5/15/2014 by Ben Lawner, DO (Emailed: 4/1/2023) (Updated: 7/3/2014)
Click here to contact Ben Lawner, DO

The Prehospital Acute Neurological Treatment and Optimization of Medical Care in Stroke Study (PHANTOM-S) was a randomized prehospital  clinical trial. On certain days, a dedicated Stroke Emergency Mobile (STEMO) responded to possible ischemic stroke incidents. Outcomes measured included time to thrombolysis and adverse events such as intracerebral hemorrhage. As opposed to usual prehospital care, a STEMO ambulance was equipped with a CT scanner, point of care laboratory, and a neurologist. According to the study, STEMO use resulted in reduced time to treatment (tPA) without adverse events. 

Though this trial did not specifically measure clinical endpoints, it addresses issues central to the delivery of specialized prehospital care:

1) Are there certain conditions which might warrant a tailored, super-specialized EMS response?
2) Are EMS systems capable of delivering definitive care to the patient as opposed to delivering the patient to definitive care? 

Stateside study has already started.  The Houston Fire Department, in partnership with UTHeath, has already loosed a "Mobile Stroke Unit" on the streets. Like the STEMO, the specialized ambulance will be University hospital based, carry a neurologist, and have the capability to administer tPA. 

STEMO pictures courtesy of the "NeuroEMS Blog"


Ebinger M, Winter B, Wendt, M, et al. Effect of the use of ambulance based thrombolysis on time to thrombolysis in acute ischemic stroke. A randomized clinical trial. JAMA. 2014;311(16):1622-1631

Lake, D. "UTHeath introduces nation's first mobile stroke unit." Available at: Accessed on May 15, 2014