Abstract WP339: Validation of the Fast-ed Scale Use by Paramedics in a Mobile Stroke Unit

Abstract

Introduction: FAST-ED scale is a helpful tool to triage stroke patients in the field. However, data on the accuracy of the scale in the pre-hospital setting is lacking. We aim to validate the use of FAST-ED by paramedics in a mobile stroke unit (MSU) covering a metropolis. Methods: As part of standard operating MSU procedures, paramedics clinically evaluated patients. If the event characterized a stroke alert, the FAST-ED score was determined by the paramedic (in-person) upon patient contact, and independently by a vascular neurologist (telemedicine) immediately after the paramedic evaluation. An MSU nurse determined the NIHSS. This will allow testing of the inter-rater agreement of the FAST-ED scoring performance between on-site pre-hospital providers and remotely located vascular neurologists. Results: In the first 13 months of the MSU’s activity 193 stroke-alert patients were evaluated. 103 (53%) patients had a final diagnosis of stroke/TIA (75/28, respectively), 21 (11%) intracranial hemorrhage, and 69 (36%) were considered stroke mimics. 28 (14%) patients received intravenous alteplase. In the first 48 patients, FAST-ED was only scored by the paramedic and in 145 patients by both the physician and paramedic. FAST-ED scores matched perfectly amongst paramedics and physicians in 77 (53%) instances, while there was only 1-point difference in 51 (35%), 2-point difference in 10 (6%) and 3-point difference in two. Correlation between physician and paramedic FAST-ED scores was highly positive (rho 0.898; 2-sided p<0.001), as well as the correlation between physicians FAST-ED score and NIHSS (rho 0.853; 2-sided p<0.001). When the physician recorded FAST-ED score≥3 (n=62), the paramedics also scored FAST-ED≥3 in the vast majority of instances (n=55; 89%). After hospital arrival, cerebrovascular imaging was deemed necessary and performed in 144 patients within 24 hours of arrival. A visible large vessel occlusion was identified in 30 patients; 18 occlusions were identified with a FAST-ED≥3 while 12 were missed (10/12 had NIHSS≤5). Conclusion: The correlation of the FAST-ED scoring between vascular neurologists and paramedics was highly positive, indicating that FAST-ED is accurately and reliably utilized by paramedics in the pre-hospital setting.