Rapid Arterial Occlusion Evaluation Scale Agreement between Emergency Medical Services Technicians and Neurologists

Design and Interrater Reliability of the Pediatric Version of the Race Scale: PedRACE

BACKGROUND

Acute ischemic stroke is a leading cause of pediatric death and disability. A clinical scale adapted for children can ensure early detection of candidates for urgent acute ischemic stroke treatment. The Rapid Arterial Occlusion Evaluation (RACE) scale for adults, which scores 5 items (facial palsy 0-2; arm motor function 0-2; leg motor function 0-2; head/gaze deviation 0-1; and aphasia or agnosia 0-2), has good sensitivity and specificity in detecting large vessel occlusion.

METHODS

We adapted the previously validated RACE scale for use in children as the Pediatric RACE scale. This adapted scale was tested by prehospital/emergency room staff attending to patients covered by the Catalan Pediatric Stroke Code and child neurologists for its correlation with the Pediatric National Institutes of Health Stroke Scale and for interrater reliability.

RESULTS

The study included 50 children, 18 with confirmed strokes (7 acute ischemic strokes and 11 hemorrhagic strokes). Prehospital/emergency staff and child neurologists agreed fully regarding 82% of patients and 100% regarding head/gaze deviation and agnosia. The Pediatric RACE scale correlated strongly with the Pediatric National Institutes of Health Stroke Scale in evaluations by child neurologists (Spearman ρ, 0.852; P<0.001) and prehospital/emergency staff (Spearman ρ, 0.781; P<0.001). The median Pediatric RACE score was significantly higher in patients with large vessel occlusion (6.5; interquartile range, 6-7) than with other etiologies.

CONCLUSIONS

Pediatric RACE, showing good interrater reliability and correlation with the Pediatric National Institutes of Health Stroke Scale, is a simple scale to detect candidates for pediatric acute stroke treatment, designed for both prehospital and in-hospital use by non-neurologist medical staff.

Inter-Rater Agreement on Cincinnati Prehospital Stroke Scale (CPSS) and Prehospital Acute Stroke Severity Scale (PASS) Between EMS Providers, Neurology Residents and Neurology Consultants

Objective

To examine the agreement between emergency medical service (EMS) providers, neurology residents and neurology consultants, using the Cincinnati Prehospital Stroke Scale (CPSS) and the Prehospital Acute Stroke Severity Scale (PASS).

Methods

Patients with stroke, transient ischemic attack (TIA) and stroke mimic were included upon primary stroke admission or during rehabilitation. Patients were included from June 2018 to September 2019. Video recordings were made of patients being assessed with CPSS and PASS. The recordings were later presented to the healthcare professionals. To determine relative and absolute interrater reliability in terms of inter-rater agreement (IRA), we used generalisability theory. Group-level agreement was determined against a gold standard and presented as an area under the curve (AUC). The gold standard was a consensus agreement between two neurology consultants.

Results

A total of 120 patient recordings were assessed by 30 EMS providers, two neurology residents and two neurology consultants. Using the CPSS and the PASS, a total of 1,800 assessments were completed by EMS providers, 240 by neurology residents and 240 by neurology consultants. The overall relative and absolute IRA for all items combined from the CPSS and PASS score was 0.84 (95% CI 0.80; 0.87) and 0.81 (95% CI 0.77; 0.85), respectively. Using the CPSS, the agreement on a group-level resulted in AUCs of 0.83 (95% CI 0.78; 0.88) for the EMS providers and 0.86 (95% CI 0.82; 0.90) for the neurology residents when compared with the gold standard. Using the PASS, the AUC was 0.82 (95% CI 0.77; 0.87) for the EMS providers and 0.88 (95% CI 0.84; 0.93) for the neurology residents.

Conclusion

The high relative and absolute inter-rater agreement underpins a high robustness/generalisability of the two scales. A high agreement exists across individual raters and different groups of healthcare professionals supporting widespread applicability of the stroke scales.

Comparison of Prehospital Assessment by Paramedics and In-Hospital Assessment by Physicians in Suspected Stroke Patients: Results From 2 Prospective Cohort Studies

BACKGROUND

It is unknown if ambulance paramedics adequately assess neurological deficits used for prehospital stroke scales to detect anterior large-vessel occlusions. We aimed to compare prehospital assessment of these stroke-related deficits by paramedics with in-hospital assessment by physicians.

METHODS

We used data from 2 prospective cohort studies: the LPSS (Leiden Prehospital Stroke Study) and PRESTO study (Prehospital Triage of Patients With Suspected Stroke). In both studies, paramedics scored 9 neurological deficits in stroke code patients in the field. Trained physicians scored the National Institutes of Health Stroke Scale (NIHSS) at hospital presentation. Patients with transient ischemic attack were excluded because of the transient nature of symptoms. Spearman rank correlation coefficient (rs) was used to assess correlation between the total prehospital assessment score, defined as the sum of all prehospital items, and the total NIHSS score. Correlation, sensitivity and specificity were calculated for each prehospital item with the corresponding NIHSS item as reference.

RESULTS

We included 2850 stroke code patients. Of these, 1528 had ischemic stroke, 243 intracranial hemorrhage, and 1079 stroke mimics. Correlation between the total prehospital assessment score and NIHSS score was strong (rs=0.70 [95% CI, 0.68-0.72]). Concerning individual items, prehospital assessment of arm (rs=0.68) and leg (rs=0.64) motor function correlated strongest with corresponding NIHSS items, and had highest sensitivity (arm 95%, leg 93%) and moderate specificity (arm 71%, leg 70%). Neglect (rs=0.31), abnormal speech (rs=0.50), and gaze deviation (rs=0.51) had weakest correlations. Neglect and gaze deviation had lowest sensitivity (52% and 66%) but high specificity (84% and 89%), while abnormal speech had high sensitivity (85%) but lowest specificity (65%).

CONCLUSIONS

The overall prehospital assessment of stroke code patients correlates strongly with in-hospital assessment. Prehospital assessment of neglect, abnormal speech, and gaze deviation differed most from in-hospital assessment. Focused training on these deficits may improve prehospital triage.

The Rapid Arterial oCclusion Evaluation (RACE) scale accuracy for diagnosis of acute ischemic stroke in emergency department - A multicenter study

OBJECTIVE

It seems that the available data on performance of the Rapid Arterial oCclusion Evaluation (RACE) as a prehospital stroke scale for differentiating all AIS cases, not only large vessel occlusion (LVO), from the stroke mimics is lacking. As a result, we intend to evaluate the accuracy of the RACE criteria in diagnosing of AIS in patients transferred to the emergency department (ED).

METHOD

The present study was a diagnostic accuracy cross-sectional study during 2021 in Iran. The study population consist of all suspected acute ischemic stroke (AIS) patients who transferred to the ED by emergency medical services (EMS). A 3-part checklist consisting of the basic and demographic information of the patients, items related to the RACE scale, and the final diagnosis of the patients based on interpretation of patients' brain MRI was used for data collection. All data were entered in Stata 14 software. We used the ROC analysis to evaluate the diagnostic power of the test.

RESULT

In this study, data from 805 patients with the mean age of 66.9 ± 13.9 years were studied of whom 57.5% were males. Of all the patients suspected of stroke who transferred to the ED, 562 (69.8%) had a definite final diagnosis of AIS. The sensitivity and specificity of the RACE scale for the recommended cut-off point (score ≥ 5) were 50.18% and 92.18%, respectively. According to the Youden J index, the best cut-off point for this tool for differentiating AIS cases was a score > 2, at which sensitivity and specificity were 74.73% and 87.65%, respectively.

CONCLUSION

It seems that, the RACE scale is an accurate diagnostic tool to detect and screen AIS patients in ED, Of course, not at the previously suggested cut-off point (score ≥ 5), but at the score > 2.

Sensitivity of prehospital stroke scales for different intracranial large vessel occlusion locations

Introduction

Prehospital stroke scales have been proposed to identify stroke patients with a large vessel occlusion to allow direct transport to an intervention centre capable of endovascular treatment (EVT). It is unclear whether these scales are able to detect not only proximal, but also more distal treatable occlusions. Our aim was to assess the sensitivity of prehospital stroke scales for different EVT-eligible occlusion locations in the anterior circulation.

Patients and methods

The MR CLEAN Registry is a prospective, observational study in all centres that perform EVT in the Netherlands. We included adult patients with an anterior circulation stroke treated between March 2014 and November 2017. We used National Institutes of Health Stroke Scale scores at admission to reconstruct previously published prehospital stroke scales. We compared the sensitivity of each scale for different occlusion locations. Occlusions were assessed with CT angiography by an imaging core laboratory blinded to clinical findings.

Results

We included 3021 patients for the analysis of 14 scales. All scales had the highest sensitivity to detect internal carotid artery terminus occlusions (ranging from 0.21 to 0.97) and lowest for occlusions of the M2 segment (0.08 to 0.84, p-values < 0.001).Discussion and conclusion: Although prehospital stroke scales are generally sensitive for proximal large vessel occlusions, they are less sensitive to detect more distal occlusions.

Validation of field assessment stroke triage for emergency destination for prehospital use in a rural EMS system

BACKGROUND

Field Assessment Stroke Triage for Emergency Destination (FAST-ED) is a simple and accurate prehospital stroke severity scale that has been shown to have comparable accuracy to the gold standard National Institutes of Health Stroke Scale (NIHSS) but requires further field validation for use by emergency medical services (EMS), particularly in rural systems. FAST-ED scores ≥4 are considered high probability for large vessel occlusion (LVO) strokes, while scores <4 are low to moderate probability for LVO. The objective of this study was to assess inter-rater reliability of the EMS FAST-ED (EMS) score to the emergency department FAST-ED (ED-MD) scores.

METHODS

EMS calculated FAST-ED scores prior to transport to the emergency department (ED) on patients with a positive prehospital stroke screen. EDMD calculated FAST-ED scores for the same patients upon arrival to the ED. Interrater reliability and test characteristics were calculated.

RESULTS

A total of 95 patients were included in this study and 14 were subsequently diagnosed with an LVO. EMS assigned 34 patients (35.8%) a FAST-ED score of ≥4. EDMD assigned 25 patients (26.3%) a FAST-ED score of ≥4. Using the clinical cut-points of FAST-ED scores <4 and ≥ 4, a linearly weighted Cohen's kappa coefficient showed moderate interrater reliability when comparing EMS and EDMD scores (k_w 0.44, 95% CI 0.25-0.63). At ≥4, EMS FAST-ED scores had a sensitivity 0.48, specificity 0.75, PPV 0.62, NPV 0.62 for predicting an LVO, while EDMD FAST-ED scores had a sensitivity 0.36, specificity 0.82, PPV 0.64, NPV 0.60. Comparable receiver operator curve area under the curve values were obtained.

CONCLUSIONS

EMS and EDMD FAST-ED scores were moderately comparable in a rural EMS system. Similar NPVs compared to EDMD suggest the use of FAST-ED as an appropriate screening tool for EMS to predict the probability of LVO in the prehospital setting and make destination determinations regarding primary transport to a thrombectomy-capable stroke center.

Large Vessel Occlusion Stroke Detection in the Prehospital Environment

Purpose of Review

Endovascular therapy for acute ischemic stroke secondary to large vessel occlusion (LVO) is time-dependent. Prehospital patients with suspected LVO stroke should be triaged directly to specialized stroke centers for endovascular therapy. This review describes advances in LVO detection among prehospital suspected stroke patients.

Recent Findings

Clinical prehospital stroke severity tools have been validated in the prehospital setting. Devices including EEG, SSEPs, TCD, cranial accelerometry, and volumetric impedance phase-shift-spectroscopy have recently published data regarding LVO detection in hospital settings. Mobile stroke units bring thrombolysis and vessel imaging to patients.

Summary

The use of a prehospital stroke severity tool for LVO triage is now widely supported. Ease of use should be prioritized as there are no meaningful differences in diagnostic performance amongst tools. LVO diagnostic devices are promising, but none have been validated in the prehospital setting. Mobile stroke units improve patient outcomes and cost-effectiveness analyses are underway.

Swiss guidelines for the prehospital phase in suspected acute stroke

Acute stroke treatment has advanced substantially over the last years. Important milestones constitute intravenous thrombolysis, endovascular therapy (EVT), and treatment of stroke patients in dedicated units (stroke units). At present in Switzerland there are 13 certified stroke units and 10 certified EVT-capable stroke centers. Emerging challenges for the prehospital pathways are that (i) acute stroke treatment remains very time sensitive, (ii) the time window for acute stroke treatment has opened up to 24 h in selected cases, and (iii) EVT is only available in stroke centers. The goal of the current guideline is to standardize the prehospital phase of patients with acute stroke for them to receive the optimal treatment without unnecessary delays. Different prehospital models exist. For patients with large vessel occlusion (LVO), the Drip and Ship model is the most commonly used in Switzerland. This model is challenged by the Mothership model where stroke patients with suspected LVO are directly transferred to the stroke center. This latter model is only effective if there is an accurate triage by paramedics, hence the patient may benefit from the right treatment in the right place, without loss of time. Although the Cincinnati Prehospital Stroke Scale is a well-established scale to detect acute stroke in the prehospital setting, it neglects nonmotor symptoms like visual impairment or severe vertigo. Therefore we suggest “acute occurrence of a focal neurological deficit” as the trigger to enter the acute stroke pathway. For the triage whether a patient has a LVO (yes/no), there are a number of scores published. Accuracy of these scores is borderline. Nevertheless, applying the Rapid Arterial Occlusion Evaluation score or a comparable score to recognize patients with LVO may help to speed up and triage prehospital pathways. Ultimately, the decision of which model to use in which stroke network will depend on local (e.g. geographical) characteristics.