Summary Background Due to the time-sensitive effect of endovascular treatment, rapid prehospital identification of large-vessel occlusion in individuals with suspected stroke is essential to optimise outcome. Interhospital transfers are an important cause of delay of endovascular treatment. Prehospital stroke scales have been proposed to select patients with large-vessel occlusion for direct transport to an endovascular-capable intervention centre. We aimed to prospectively validate eight prehospital stroke scales in the field. Methods We did a multicentre, prospective, observational cohort study of adults with suspected stroke (aged ≥18 years) who were transported by ambulance to one of eight hospitals in southwest Netherlands. Suspected stroke was defined by a positive Face-Arm-Speech-Time (FAST) test. We included individuals with blood glucose of at least 2·5 mmol/L. People who presented more than 6 h after symptom onset were excluded from the analysis. After structured training, paramedics used a mobile app to assess items from eight prehospital stroke scales: Rapid Arterial oCclusion Evaluation (RACE), Los Angeles Motor Scale (LAMS), Cincinnati Stroke Triage Assessment Tool (C-STAT), Gaze-Face-Arm-Speech-Time (G-FAST), Prehospital Acute Stroke Severity (PASS), Cincinnati Prehospital Stroke Scale (CPSS), Conveniently-Grasped Field Assessment Stroke Triage (CG-FAST), and the FAST-PLUS (Face-Arm-Speech-Time plus severe arm or leg motor deficit) test. The primary outcome was the clinical diagnosis of ischaemic stroke with a proximal intracranial large-vessel occlusion in the anterior circulation (aLVO) on CT angiography. Baseline neuroimaging was centrally assessed by neuroradiologists to validate the true occlusion status. Prehospital stroke scale performance was expressed as the area under the receiver operating characteristic curve (AUC) and was compared with National Institutes of Health Stroke Scale (NIHSS) scores assessed by clinicians at the emergency department. This study was registered at the Netherlands Trial Register, NL7387. Findings Between Aug 13, 2018, and Sept 2, 2019, 1039 people (median age 72 years [IQR 61–81]) with suspected stroke were identified by paramedics, of whom 120 (12%) were diagnosed with aLVO. Of all prehospital stroke scales, the AUC for RACE was highest (0·83, 95% CI 0·79–0·86), followed by the AUC for G-FAST (0·80, 0·76–0·84), CG-FAST (0·80, 0·76–0·84), LAMS (0·79, 0·75–0·83), CPSS (0·79, 0·75–0·83), PASS (0·76, 0·72–0·80), C-STAT (0·75, 0·71–0·80), and FAST-PLUS (0·72, 0·67–0·76). The NIHSS as assessed by a clinician in the emergency department did somewhat better than the prehospital stroke scales with an AUC of 0·86 (95% CI 0·83–0·89). Interpretation Prehospital stroke scales detect aLVO with acceptable-to-good accuracy. RACE, G-FAST, and CG-FAST are the best performing prehospital stroke scales out of the eight scales tested and approach the performance of the clinician-assessed NIHSS. Further studies are needed to investigate whether use of these scales in regional transportation strategies can optimise outcomes of patients with ischaemic stroke. Funding BeterKeten Collaboration and Theia Foundation (Zilveren Kruis).

Comparison of eight prehospital stroke scales to detect intracranial large-vessel occlusion in suspected stroke (PRESTO): a prospective observational study

BackgroundThe diagnosis of stroke in the prehospital environment is the subject of intense interest and research. There are a number of non-invasive external brain monitoring devices in development...

Non-invasive sensor technology for prehospital stroke diagnosis: Current status and future directions.

Acute stroke management has been revolutionised by evidence of the effectiveness of thrombectomy. Because time is brain in stroke care, the speed with which a patient with large vessel occlusion is transferred to a thrombectomy-capable centre determines outcome. Therefore, each link in the stroke rescue chain, starting with symptom onset and ending with recanalisation, should be streamlined. However, in contrast to inhospital delays, prehospital delays are unchanged despite substantial efforts in quality improvement. Furthermore, thrombectomy is offered by only a few, usually distant, specialised centres and not by the many other, usually nearer, hospitals. To take maximum advantage of the first so-called golden hours after stroke, and because of the difficulty of on-scene triage decision making with respect to the target hospital offering the required level of care, the focus of stroke research has shifted to the prehospital setting. Current research focuses on the effects of public education, implementation of protocols for emergency medical services for streamlining clinical investigations and accurate triage, use of preclinical scales for stroke recognition, and deployment of novel technical solutions such as smartphone applications, telemedicine, and mobile stroke units.

Prehospital stroke management in the thrombectomy era

Background and Purpose- Patients with acute ischemic stroke who have large vessel occlusion benefit from direct transport to a comprehensive stroke center (CSC) capable of endovascular therapy. To avoid harm for patients without large vessel occlusion from delayed access to intravenous thrombolysis (IVT), it has been suggested to only redirect patients with high likelihood of large vessel occlusion for whom the additional delay to intravenous thrombolysis (IVT) caused by transport to the CSC is below a certain threshold. However, which threshold achieves the greatest clinical benefit is unknown. Methods- We used mathematical modeling to calculate additional-delay-to-IVT thresholds associated with the greatest reduction in disability-adjusted life years in abstracted 2-stroke center and multiple-stroke center scenarios. Model parameters were extracted from recent meta-analyses or large prospective cohort studies. Uncertainty was quantified in probabilistic and 2-way univariate sensitivity analyses. Results- Assuming ideal treatment time performance metrics, transport to the nearest CSC was the preferred strategy irrespective of additional delay-to-IVT when the transfer time between primary stroke center and CSC was <40 minutes (95% credible interval: 25-66 minutes); otherwise, the optimal additional delay-to-IVT-threshold ranged from 28 to 139 minutes. In multiple-stroke center scenarios, optimal additional-delay-to-IVT thresholds were 30 to 54 minutes in urban and 49 to 141 minutes in rural settings; use of optimal thresholds as compared with a 15 minute-threshold saved 0 to 0.11 and 0 to 0.37 disability-adjusted life years per triage case, respectively. Assuming slower treatment times at primary stroke centers and CSCs yielded longer permissible additional delays. Conclusions- Our results suggest that patients with acute ischemic stroke with suspected large vessel occlusion should be redirected to a CSC if the additional delay to IVT is <30 minutes in urban and 50 minutes in rural settings.

https://www.ahajournals.org/doi/pdf/10.1161/STROKEAHA.119.027512

Bypassing the Closest Stroke Center for Thrombectomy Candidates: What Additional Delay to Thrombolysis Is Acceptable?

Background Data on the implementation of prehospital large vessel occlusion (LVO) scales to identify and triage patients with acute ischemic stroke (AIS) in the field are limited, with the majority of studies occurring outside the USA. Objective To report our long-term experience of a US countywide emergency medical services (EMS) acute stroke triage protocol using the Rapid Arterial oCclusion Evaluation (RACE) score. Methods Our prospective database was used to identify all consecutive patients triaged within Lucas County, Ohio by the EMS with (1) a RACE score ≥5, taken directly to an endovascular capable center (ECC) as RACE-alerts (RA) and (2) a RACE score Results Between July 2015 and June 2018, 492 RA and 1147 SA were triaged within our five-hospital network. Of the RA, 37% had AIS secondary to LVOs. Of the 492 RA and 1147 SA, 125 (25.4%) and 38 (3.3%), respectively, underwent MT (OR=9.9; 95% CI 6.8 to 14.6; p Conclusions We have demonstrated the long-term feasibility of a countywide EMS-based prehospital triage protocol using the RACE Scale within our hospital network.

https://jnis.bmj.com/content/neurintsurg/12/1/19.full.pdf

Long-term implementation of a prehospital severity scale for EMS triage of acute stroke: a real-world experience

Performance of the RACE Score for the Prehospital Identification of Large Vessel Occlusion Stroke in a Suburban/Rural EMS Service

Background Tube thoracostomy has long been the standard of care for treatment of tension pneumothorax in the hospital setting yet is uncommon in prehospital care apart from helicopter emergency medical services. Objective We aimed to evaluate the performance of simple thoracostomy (ST) for patients with traumatic cardiac arrest and suspected tension pneumothorax. Methods We conducted a retrospective case series of consecutive patients with traumatic cardiac arrest where simple thoracostomy was used during the resuscitation effort. Data were abstracted from our Zoll emergency medical record (Zoll Medical Corp., Chelmsford, MA) for patients who received the procedure between June 1, 2013 and July 1, 2017. We collected general descriptive characteristics, procedural success, presence of air or blood, and outcomes for each patient. Results During the study period we performed ST on 57 patients. The mean age was 41 years old (range 15–81 years old) and 83% were male. Indications included 40 of 57 (70%) blunt trauma and 17 of 57 (30%) penetrating trauma. The presenting rhythm was pulseless electrical activity 65%, asystole 26%, ventricular tachycardia/fibrillation 4%, and nonrecorded 5%. Eighteen of 57 (32%) had air return, 14 of 57 (25%) return of spontaneous circulation, with 6 of 57 (11%) surviving to 24 h and 4 of 57 (7%) discharged from the hospital neurologically intact. Of the survivors, all were blunt trauma mechanism with initial rhythms of pulseless electrical activity. There were no reported medic injuries. Conclusions Our data show that properly trained paramedics in ground-based emergency medical services were able to safely and effectively perform ST in patients with traumatic cardiac arrest. We found a significant (32%) presence of pneumothorax in our sample, which supports previously reported high rates in this patient population.

Emergency Medical Services Simple Thoracostomy for Traumatic Cardiac Arrest: Postimplementation Experience in a Ground-based Suburban/Rural Emergency Medical Services Agency.

Christopher Mason

Papers

Performance of the RACE Score for the Prehospital Identification of Large Vessel Occlusion Stroke in a Suburban/Rural EMS Service

Emergency Medical Services Simple Thoracostomy for Traumatic Cardiac Arrest: Postimplementation Experience in a Ground-based Suburban/Rural Emergency Medical Services Agency.