Validation of a shortened FAST-ED algorithm for smartphone app guided stroke triage

 But what about those strokes at the back of the head that don't have the classic symptoms? You're supposed to be planning on how to treat all patients.

AHA News: Revised Scale Could Lead to Timelier Treatment for Strokes in the Back of the Head

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Validation of a shortened FAST-ED algorithm for smartphone app guided stroke triage

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Benedikt Frank, Felix Fabian, Bastian Brune, ...

First Published November 23, 2021 Research Article 

https://doi.org/10.1177/17562864211057639

Article information

Abstract

Background and Purpose:

Large vessel occlusion (LVO) recognition scales were developed to identify patients with LVO-related acute ischemic stroke (AIS) on the scene of emergency. Thus, they may enable direct transport to a comprehensive stroke centre (CSC). In this study, we aim to validate a smartphone app-based stroke triage with a shortened form of the Field Assessment Stroke Triage for Emergency Destination (FAST-ED).

Methods:

This retrospective validation study included 2815 patients with confirmed acute stroke and suspected acute stroke but final diagnosis other than stroke (stroke mimics) who were admitted by emergency medical service (EMS) to the CSC of the Neurological University Hospital Essen, Germany. We analysed the predictive accuracy of a shortened digital app-based FAST-ED ( ‘FAST-ED App’) for LVO-related AIS and yield comparison to various other LVO recognition scales.

Results:

The shortened FAST-ED App had comparable test quality (Area under ROC = 0.887) to predict LVO-related AIS to the original FAST-ED (0.889) and RACE (0.883) and was superior to Cincinnati Prehospital Stroke Severity (CPSS), 3-Item Stroke Scale (3-ISS) and National Institute of Health Stroke Scale (NIHSS). A FAST-ED App ⩾ 4 revealed very good accuracy to detect LVO related AIS (sensitivity of 77% and a specificity 87%) with an area under the curve c-statistics of 0.89 (95% CI: 0.87–0.90). In a hypothetical triage model, the number needed to screen in order to avoid one secondary transportation in an urban setting would be five.

Conclusion:

This validation study of a shortened FAST-ED assessment for a smartphone-app guided stroke triage yields good quality to identify patients with LVO.

Keywords

EMS, FAST-ED, identification, LVO, prehospital, Stroke Triage, thrombectomy

Introduction

Rapid treatment of patients with acute ischemic stroke (AIS) is crucial to improve functional outcome. While intravenous thrombolysis (IVT) is available in a large number of hospitals, Comprehensive Stroke Centres (CSCs) providing endovascular treatment (EVT) for patients with large vessel occlusion (LVO) are limited.

At present, the pre-hospital identification of LVO-related ischemic stroke and direct transport of those patients to a CSC is an untapped opportunity to shorten time to revascularization and has the potential to improve outcome. Secondary interhospital transfer to CSC after start of IVT (drip-and-ship) is known to delay treatment initiation of EVT.¹ Even though the other also important component of recanalization treatment, the IVT,^2–5 can be administered without delay, the drip-and-ship concept is associated with less favourable outcome in EVT-patients.¹ In addition, direct transport would reduce the overall number of secondary interhospital transfers, thus saving precious resources in the prehospital ambulance service.⁶

To optimize allocation for patients with suspected stroke, several LVO recognition scales that easily can be used by Emergency Medical Services (EMS) have been proposed. Among these, the Rapid Arterial Occlusion Evaluation (RACE) and the Field Assessment Stroke Triage for Emergency Destination (FAST-ED) have shown to be superior to other LVO recognition scales.⁷ For both scales smartphone app versions are available.⁸ This provides the opportunity to digitally transmit the results to the target hospital stroke team prior to hospital admission. However, the algorithm of the app based FAST-ED differs from the validated FAST-ED version, as the app interactively adjusts the assessment so that neglect and denial are only evaluated, if the patient has arm-weakness and no disturbance in speech comprehension. Thus, app version of FAST-ED is slightly shorter and ranges from 0 to 8 possible points instead of 0 to 9 points. In this study, we aim to validate the app version of FAST-ED and compare test quality with available LVO recognition scales.

More at link.

 

Field Assessment Stroke Triage for Emergency Destination

I can't find the  FAST-ED tool so you will just have to take their word for it that it is good. It is your brain that is dying. Wouldn't the same have to be done for large hemorrhagic strokes also?
http://stroke.ahajournals.org/content/47/8/1997.abstract?etoc

A Simple and Accurate Prehospital Scale to Detect Large Vessel Occlusion Strokes

1. Fabricio O. Lima, MD, MPH, PhD;
2. Gisele S. Silva, MD, MPH, PhD;
3. Karen L. Furie, MD, MPH;
4. Michael R. Frankel, MD;
5. Michael H. Lev, MD;
6. Érica C.S. Camargo, MD, PhD, MSc;
7. Diogo C. Haussen, MD;
8. Aneesh B. Singhal, MD;
9. Walter J. Koroshetz, MD;
10. Wade S. Smith, MD;
11. Raul G. Nogueira, MD

+ Author Affiliations

1. From the Centro de Ciências da Saúde, Curso de Medicina, Universidade de Fortaleza, Fortaleza-CE, Brazil (F.O.L.); Neurovascular Service, Department of Neurology, Federal University of São Paulo, São Paulo-SP, Brazil (G.S.S.); Department of Neurology, Brown University, Providence, RI (K.L.F.); Neuroendovascular and Neurocritical Care Services, Marcus Stroke and Neuroscience Center, Grady Memorial Hospital, Emory University School of Medicine, Atlanta, GA (M.R.F., D.C.H., R.G.N.); Department of Radiology (M.H.L.) and Stroke Service, Department of Neurology (É.C.S.C., A.B.S.), Massachusetts General Hospital, Boston; National Institutes of Health, National Institute of Neurological Disorders and Stroke, Bethesda, MD (W.J.K.); and UCSF Neurovascular Service, Department of Neurology, University of California San Francisco (W.S.S.).

1. Correspondence to Raul G. Nogueira, MD, 49 Jesse Hill Dr, SE Room No. 333, Atlanta, GA 30303. E-mail raul.g.nogueira@emory.edu

Abstract

Background and Purpose—Patients with large vessel occlusion strokes (LVOS) may be better served by direct transfer to endovascular capable centers avoiding hazardous delays between primary and comprehensive stroke centers. However, accurate stroke field triage remains challenging. We aimed to develop a simple field scale to identify LVOS.

Methods—The Field Assessment Stroke Triage for Emergency Destination (FAST-ED) scale was based on items of the National Institutes of Health Stroke Scale (NIHSS) with higher predictive value for LVOS and tested in the Screening Technology and Outcomes Project in Stroke (STOPStroke) cohort, in which patients underwent computed tomographic angiography within the first 24 hours of stroke onset. LVOS were defined by total occlusions involving the intracranial internal carotid artery, middle cerebral artery-M1, middle cerebral artery-2, or basilar arteries. Patients with partial, bihemispheric, and anterior+posterior circulation occlusions were excluded. Receiver operating characteristic curve, sensitivity, specificity, positive predictive value, and negative predictive value of FAST-ED were compared with the NIHSS, Rapid Arterial Occlusion Evaluation (RACE) scale, and Cincinnati Prehospital Stroke Severity (CPSS) scale.

Results—LVO was detected in 240 of the 727 qualifying patients (33%). FAST-ED had comparable accuracy to predict LVO to the NIHSS and higher accuracy than RACE and CPSS (area under the receiver operating characteristic curve: FAST-ED=0.81 as reference; NIHSS=0.80, P=0.28; RACE=0.77, P=0.02; and CPSS=0.75, P=0.002). A FAST-ED ≥4 had sensitivity of 0.60, specificity of 0.89, positive predictive value of 0.72, and negative predictive value of 0.82 versus RACE ≥5 of 0.55, 0.87, 0.68, and 0.79, and CPSS ≥2 of 0.56, 0.85, 0.65, and 0.78, respectively.

Conclusions—FAST-ED is a simple scale that if successfully validated in the field, it may be used by medical emergency professionals to identify LVOS in the prehospital setting enabling rapid triage of patients.