Kevin S. Attenhofer, MD
The spectrum of acute ischemic stroke (AIS) care begins well before the emergency room. EMS first responders are often the first to examine the patient and consider the diagnosis of stroke. There are multiple triage scores and systems in place to assist EMS. Options include the Cincinnati Prehospital Stroke Scale (CPSS), Face Arm Speech Test (FAST), Los Angeles Prehospital Stroke Screen (LAPSS), etc. Most of these scales focus on identifying common findings of subcortical strokes (facial droop, hemiparesis). In 2014, Spanish researchers created and published the Rapid Arterial Occlusion Evaluation (RACE) Scale, which included cortical, as well as subcortical, exam findings to aid with pre-hospital identification of patients with higher likelihood of having a large vessel occlusion (LVO). In addition to facial palsy and hemiparesis, the RACE scale also scores gaze deviation, aphasia, and agnosia.
Clinical implications of the RACE scale are unclear. One ongoing clinical trial, RACECAT, is comparing direct transfer of patients with a high RACE score (> 4) to an endovascular center versus taking these patients to the closest acute stroke center (without endovascular capabilities) with subsequent “drip and ship” of patients determined to have an LVO. With those results not expected until 2020, Schlemm et al have implemented a conditional probabilistic model to calculate probabilities of good outcome (modified Rankin Scale ≤ 2 after 3 months) for triage of AIS patients with unknown vessel status to either a “mothership” approach (direct to endovascular center) or “drip and ship” approach.