Abstract TP122: Validation of the Vision Aphasia Neglect (VAN) Screening Tool for Clinical Diagnosis of Emergent Large Vessel Occlusion

BackgroundIdentification of emergent large vessel occlusion (ELVO) stroke has become increasingly important with the recent publications of favorable acute stroke thrombectomy trials. Multiple screening tools exist but the length of the examination and the false positive rate range from good to adequate. A screening tool was designed and tested in the emergency department using nurse responders without a scoring system.MethodsThe vision, aphasia, and neglect (VAN) screening tool was designed to quickly assess functional neurovascular anatomy. While objective, there is no need to calculate or score with VAN. After training participating nurses to use it, VAN was used as an ELVO screen for all stroke patients on arrival to our emergency room before physician evaluation and CT scan.ResultsThere were 62 consecutive code stroke activations during the pilot study. 19 (31%) of the patients were VAN positive and 24 (39%) had a National Institutes of Health Stroke Scale (NIHSS) score of ≥6. All 14 patients with ELVO were either VAN positive or assigned a NIHSS score ≥6. While both clinical severity thresholds had 100% sensitivity, VAN was more specific (90% vs 74% for NIHSS ≥6). Similarly, while VAN and NIHSS ≥6 had 100% negative predictive value, VAN had a 74% positive predictive value while NIHSS ≥6 had only a 58% positive predictive value.ConclusionsThe VAN screening tool accurately identified ELVO patients and outperformed a NIHSS ≥6 severity threshold and may best allow clinical teams to expedite care and mobilize resources for ELVO patients. A larger study to both validate this screening tool and compare with others is warranted.

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Abstract TP258: Large Vessel Occlusion Screening Tool for Acute Ischemic Stroke Patients

Stroke ◽

10.1161/str.48.suppl_1.tp258 ◽

2017 ◽

Vol 48 (suppl_1) ◽

Author(s):

Ilana M Ruff ◽

Fan Z Caprio ◽

Linda Jiang ◽

Scott J Mendelson ◽

Christopher T Richards ◽

...

Keyword(s):

Ischemic Stroke ◽

Acute Ischemic Stroke ◽

Cerebral Artery ◽

Screening Tool ◽

Large Vessel ◽

Rapid Screening ◽

Large Vessel Occlusion ◽

Anterior Circulation ◽

Vessel Occlusion ◽

Predictive Values

Introduction: With randomized data proving the benefit of endovascular therapy for large vessel occlusion (LVO), there is increasing interest in developing a rapid screening tool to predict LVO in acute ischemic stroke (AIS) patients in the emergency department (ED) setting. Methods: We implemented a new LVO screening tool in our ED in March 2016. The LVO score ranged from 0-6 and included one point for each of the following individual components: level of consciousness, gaze deviation, aphasia, dysarthria, facial droop, and arm weakness. LVO was defined as an intracranial occlusion of the internal carotid artery, M1 and M2 segments of the middle cerebral artery, A1 and A2 segments of the anterior cerebral artery, P1 and P2 segments of the posterior cerebral artery, basilar artery, or vertebral arteries. We calculated c-statistics to determine the discrimination of the LVO score for presence of LVO on emergent vascular imaging and identified the optimal cut-off score with maximum sensitivity and specificity. Results: Among 65 consecutive confirmed AIS patients between March and July 2016, 63.1% had a positive LVO screen (score > 0); 97% of the patients underwent emergent CT angiography. Eleven (16.9%) patients had an LVO in the territory of ischemic infarct, 10 of which were in the anterior circulation. The LVO score had a c-statistic of 0.77 (95%CI 0.59-0.96, p< 0.005) for predicting LVO. An optimal cut-off score > 2 was present in 19 patients (29.2%) and was associated with 72.7% sensitivity and 79.6% specificity; positive and negative predictive values were 42.1% and 93.5%, respectively. Conclusions: In a preliminary analysis, a simple LVO screening tool had acceptable discrimination for predicting LVO in AIS patients in the ED. Further validation and refinement of the tool is necessary.

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Abstract TP393: Standardization of Large Vessel Occlusion Assessment With Designated Stroke Zone Decreases Door in Door Out Times

Stroke ◽

10.1161/str.51.suppl_1.tp393 ◽

2020 ◽

Vol 51 (Suppl_1) ◽

Author(s):

Kimberley Duke ◽

Richelle Hartman ◽

Jeffrey Roth

Keyword(s):

Best Practices ◽

Screening Tool ◽

Assessment Tool ◽

Early Recognition ◽

Large Vessel ◽

Large Vessel Occlusion ◽

Vessel Occlusion ◽

Stroke Population ◽

Before And After ◽

Evaluation Of Data

Background and Purpose: Increased Door in door out (DIDO) times prompted a change in the “Code Stroke” process in three sister Primary Stroke Centers. It was observed that utilizing a NIHSS >6 was insufficient in recognizing potential large vessel occlusion (LVO) candidates and correlated with an increase in the DIDO times of patients presenting to the Emergency Department (ED) with large vessel symptoms. After a “pilot” of the Vision, Aphasia, and Neglect (VAN) assessment tool in 2017, all three facilities initiated changes to the “Code Stroke” process. These changes included the implementation of the VAN assessment and the designation of a “Stroke Zone”. Methods: Data was collected from 2016 through the second quarter of 2019 on all “Code Strokes” activated in the ED. This data was analyzed to determine the efficacy of implementing the VAN assessment and designation of a “Stroke Zone”. Nursing staff and ED providers were educated on the utilization of the VAN assessment tool and the inclusion of a Computed Tomography Angiography (CTA) on patients presenting with a positive VAN assessment and symptom onset less than 24 hours. The number of Mechanical Endovascular Reperfusion (MER) candidates and the average DIDO times per quarter were compared before and after the implementation of the changes. Results: Evaluation of data from the three facilities showed that implementing a standardized LVO assessment tool in conjunction with a designated “Stroke Zone” increased the identification of potential LVO candidates and decreased DIDO times. Conclusion: The standardization of an LVO screening tool and utilization of a dedicated “Stroke Zone” contributed to a decrease in DIDO times in all three facilities. Efficacy of the changes to the process will assist in supporting best practices while caring for patients in the Stroke population. In addition, the early recognition of LVO candidates will positively impact Door to Needle times.

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Abstract TP262: Pre-Hospital VAN Large Vessel Occlusion Screening Tool Predicts Larger Intracerebral Hemorrhage

Stroke ◽

10.1161/str.51.suppl_1.tp262 ◽

2020 ◽

Vol 51 (Suppl_1) ◽

Author(s):

Arash Shadman ◽

Aaisha Mozumder ◽

Mateja de Leonni Stanonik ◽

Michele Patterson ◽

David Wampler ◽

...

Keyword(s):

Intracerebral Hemorrhage ◽

Validation Study ◽

Screening Tool ◽

San Antonio ◽

Large Vessel ◽

Large Vessel Occlusion ◽

Vessel Occlusion ◽

Exact Test ◽

Stroke Mimics ◽

Fisher’S Exact Test

Introduction: An EMS validation study in San Antonio, Texas previously evaluated the Vision Aphasia Neglect (VAN) screen to identify large vessel occlusion (LVO) in the prehospital setting. Because it may be used in the field to bypass hospitals for higher level care, VAN’s performance with stroke mimics, specifically intracerebral hemorrhage (ICH), is important in stroke systems of care. The goal of this study was to determine if a positive VAN assessment correlated with larger ICH. Methods: Paramedics from two San Antonio EMS agencies documented a VAN assessment from June 2017 to April 2019 for all EMS stroke alerts less than 6 hours from last known well. The prehospital VAN score, emergency department advanced neuroimaging interpretation, and hospital discharge diagnosis were collected from three comprehensive stroke centers. Stroke mimics and hemorrhages were included. ICH volume, location, and presence of intraventricular hemorrhage (IVH) were recorded. ICH volume and location were dichotomized by the median value and infratentorial versus supratentorial, respectively. Descriptive statistics were used for continuous data, and categorical data was analyzed by Fisher’s exact test. Results: VAN scores were recorded for 215 EMS activated stroke alerts, of which 131 (60.9%) were VAN positive and 23 (10.7%) were ICH. All were hypertensive etiologies except one arteriovenous malformation related hemorrhage. ICH mean and median values were 15.3 ml and 10.3 ml (range 0.3 - 51 ml), respectively. Of the 23 ICH cases, IVH was present in 7 (30%), and infratentorial location was noted in 4 (17%). Fisher’s exact test for VAN and ICH (categorized as ≥ or < median volume) was significant (0.027, p<0.05). However, VAN versus both ICH location and presence of IVH was non-significant. Conclusion: In this prospective EMS validation study, a pre-hospital VAN positive assessment predicted larger ICH volumes. Although VAN was designed to identify LVO, pre-hospital triage of ICH is an additional benefit of this screening tool. A false positive VAN assessment for LVO may signify a larger ICH, which is often transferred to higher level centers as standard of care. Thus, VAN perform well for both ischemic and hemorrhagic hospital bypass protocols.

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