Prehospital thrombolysis in acute stroke: results of the PHANTOM-S pilot study

Mobile stroke units: Beyond thrombolysis

In the last decade, mobile stroke units (MSUs) have shown the potential to transform prehospital stroke care, marking a paradigm shift in delivering ultra-rapid thrombolysis and streamlining triage processes. These units bring acute stroke care directly to patients, significantly shortening treatment times. This review outlines the rationale for MSU care and discusses the potential applications beyond the original purpose of delivering thrombolysis, including large vessel occlusion detection, intracerebral hemorrhage management, and innovative forms of prehospital research.

Mobile Stroke Units in Acute Ischemic Stroke: A Comprehensive Systematic Review and Meta-Analysis of 5 "T Letter" Domains

Intravenous thrombolysis (IVT) may be administered to stroke patients requiring immediate treatment more quickly than emergency medical services if certain conditions are met. These conditions include the presence of mobile stroke units (MSUs) with on-site treatment teams and a computed tomography scanner. We compared clinical outcomes of MSU conventional therapy by emergency medical services through a systematic review and meta-analysis. We searched key electronic databases from inception till September 2021. The primary outcomes were mortality at 7 and 90 days. The secondary outcomes included the modified Rankin Scale score at 90 days, alarm to IVT or intra-arterial recanalization, and time from symptom onset or last known well to thrombolysis. We included 19 controlled trials and cohort studies to conduct our final analysis. Our comparison revealed that 90-day mortality significantly decreased in the MSU group compared with the conventional care group [risk ratio = 0.82; 95% confidence interval (CI), 0.71-0.95], while there was no significant difference at 7 days (risk ratio = 0.89; 95% CI, 0.69-1.15). MSU achieved greater functional independence (modified Rankin Scale = 0-2) at 90 days (risk ratio = 1.08; 95% CI, 1.01-1.16). MSU was associated with shorter alarm to IVT or intra-arterial recanalization time (mean difference = -29.69; 95% CI, -34.46 to -24.92), treating patients in an earlier time window, as shown through symptom onset or last known well to thrombolysis (mean difference = -36.79; 95% CI, -47.48 to -26.10). MSU-treated patients had a lower rate of 90-day mortality and better 90-day functional outcomes by earlier initiation of IVT compared with conventional care.

Effectiveness of the acute stroke care map program in reducing in-hospital delay for acute ischemic stroke in a Chinese urban area: an interrupted time series analysis

Background

Timely intravenous thrombolysis (IVT) is crucial for improving outcomes in acute ischemic stroke (AIS) patients. This study evaluates the effectiveness of the Acute Stroke Care Map (ASCaM) initiative in Shenyang, aimed at reducing door-to-needle times (DNT) and thus improving the timeliness of care for AIS patients.

Methods

An retrospective cohort study was conducted from April 2019 to December 2021 in 30 hospitals participating in the ASCaM initiative in Shenyang. The ASCaM bundle included strategies such as EMS prenotification, rapid stroke triage, on-call stroke neurologists, immediate neuroimaging interpretation, and the innovative Pre-hospital Emergency Call and Location Identification feature. An interrupted time series analysis (ITSA) was used to assess the impact of ASCaM on DNT, comparing 9 months pre-intervention with 24 months post-intervention.

Results

Data from 9,680 IVT-treated ischemic stroke patients were analyzed, including 2,401 in the pre-intervention phase and 7,279 post-intervention. The ITSA revealed a significant reduction in monthly DNT by -1.12 min and a level change of -5.727 min post-ASCaM implementation.

Conclusion

The ASCaM initiative significantly reduced in-hospital delays for AIS patients, demonstrating its effectiveness as a comprehensive stroke care improvement strategy in urban settings. These findings highlight the potential of coordinated care interventions to enhance timely access to reperfusion therapies and overall stroke prognosis.

Optimization of sensitivity and specificity of a biomarker-based blood test (LVOCheck-Opti): A protocol for a multicenter prospective observational study of patients suspected of having a stroke

Introduction

Acute ischemic stroke (AIS) is a time-critical medical emergency. For patients with large-vessel occlusions (LVO), mechanical thrombectomy (MT) is the gold-standard treatment. Mobile Stroke Units (MSUs) provide on-site diagnostic capabilities via computed tomography (CT) and have been shown to improve functional outcomes in stroke patients, but are cost-efficient only in urban areas. Blood biomarkers have recently emerged as possible alternative to cerebral imaging for LVO diagnosis. Prehospital LVO diagnosis offers the potential to transport patients directly to centers that have MT treatment available. In this study, we assess the accuracy of combining two biomarkers, HFABP and NT-proBNP, with clinical indicators to detect LVO using ultra-early prehospital blood samples. The study was registered in the German Clinical Trials Register (DRKS-ID: DRKS00030399).

Methods and analysis

We plan a multicenter prospective observational study with 800 patients with suspected stroke enrolled within 24 h of symptom onset. Study participants will be recruited at three sites (MSUs) in Berlin, Germany. Blood-samples will be taken pre-hospitally at the scene and tested for HFABP and NT-proBNP levels. Additional clinical data and information on final diagnosis will be collected and documented in an electronic case report form (eCRF). Sensitivity and specificity of the combination will be calculated through iterative permutation-response calculations.

Discussion

This study aims to evaluate the diagnostic capabilities of a combination of the biomarkers HFABP and NT-proBNP in LVO prediction. In contrast to most other biomarker studies to date, by employing MSUs as study centers, ultra-early levels of biomarkers can be analyzed. Point-of-care LVO detection in suspected stroke could lead to faster treatment in both urban and rural settings and thus improve functional outcomes on a broader scale.

Clinical trial registration

Deutsches Register klinischer Studien https://drks.de/search/de/trial/DRKS00030399, DRKS00030399.

Brain injury mobile diagnostic system: Applications in civilian medical service and on the battlefield-General concept and medical aspects

To present the concept of a portable ultrasound tomography device for diagnosing traumatic and vascular brain lesions. The device consisting of multiple transcranial ultrasound probes placed on the surface of the head, specifically but not exclusively in natural acoustic windows. An integral part of the mobile diagnostic system (MDS) is a decision support system based on artificial intelligence algorithms utilizing information from: head images, laboratory data, and assessment of the patient's clinical condition. The MDS can significantly reduce the time from stroke onset to rtPA therapy in civilian medical services and support therapeutic and evacuation strategies in instances of brain and skull trauma on the battlefield.

Prospective collection of blood plasma samples to identify potential biomarkers for the prehospital stroke diagnosis (ProGrEss-Bio): study protocol for a multicenter prospective observational study

Introduction

Intravenous thrombolysis (IVT) and mechanical thrombectomy (MT) are well-established, evidence-based, time-critical therapies that reduce morbidity and mortality in acute ischemic stroke (AIS) patients. The exclusion of intracerebral hemorrhage (ICH) is mandatory and has been performed by cerebral imaging to date. Mobile stroke units (MSUs) have been shown to improve functional outcomes by bringing cerebral imaging and IVT directly to the patient, but they have limited coverage. Blood biomarkers clearly distinguishing between AIS, ICH, and stroke mimics (SM) could provide an alternative to cerebral imaging if concentration changes are detectable in the hyperacute phase after stroke with high diagnostic accuracy. In this study, we will take blood samples in a prehospital setting to evaluate potential biomarkers. The study was registered in the German Clinical Trials Register (https://drks.de/search/de) with the identifier DRKS00023063.

Methods and analysis

We plan a prospective, observational study involving 300 patients with suspected stroke and symptom onset of ≤4.5 h before the collection of biomarkers. Study participants will be recruited from three sites in Berlin, Germany during MSU deployments. The focus of the study is the collection of blood samples from participants at the prehospital scene and from participants with AIS or ICH at a second-time point. All samples will be analyzed using targeted and untargeted analytical approaches. Study-related information about participants, including medical information and discharge diagnoses from the subsequent treating hospital, will be collected and documented in an electronic case report form (eCRF).

Discussion

This study will evaluate whether a single blood biomarker or a combination of biomarkers can distinguish patients with AIS and ICH from patients with stroke and SM in the early phase after symptom onset in the prehospital setting. In addition, the kinetics of blood biomarkers in AIS and ICH patients will be investigated. Our goal is to evaluate new ways to reliably diagnose stroke in the prehospital setting and thus accelerate the application of evidence-based therapies to stroke patients.

Modeling the potential efficiency of a blood biomarker-based tool to guide pre-hospital thrombolytic therapy in stroke patients

OBJECTIVES

Stroke treatment with intravenous tissue-type plasminogen activator (tPA) is effective and efficient, but as its benefits are highly time dependent, it is essential to treat the patient promptly after symptom onset. This study evaluates the cost-effectiveness of a blood biomarker test to differentiate ischemic and hemorrhagic stroke to guide pre-hospital treatment with tPA in patients with suspected stroke, compared with standard hospital management. The standard care for patients suffering stroke consists mainly in diagnosis, treatment, hospitalization and monitoring.

METHODS

A Markov model was built with four health states according to the modified Rankin scale, in adult patients with suspected moderate to severe stroke (NIHSS 4-22) within 4.5 hours after symptom onset. A Spanish Health System perspective was used. The time horizon was 15 years. Quality-adjusted life-years (QALYs) and life-years gained (LYGs) were used as a measure of effectiveness. Short- and long-term direct health costs were included. Costs were expressed in Euros (2022). A discount rate of 3% was used. Probabilistic sensitivity analysis and several one-way sensitivity analyses were conducted.

RESULTS

The use of a blood-test biomarker compared with standard care was associated with more QALYs (4.87 vs. 4.77), more LYGs (7.18 vs. 7.07), and greater costs (12,807€ vs. 12,713€). The ICER was 881€/QALY. Probabilistic sensitivity analysis showed that the biomarker test was cost-effective in 82% of iterations using a threshold of 24,000€/QALY.

CONCLUSIONS

The use of a blood biomarker test to guide pre-hospital thrombolysis is cost-effective compared with standard hospital care in patients with ischemic stroke.

European Stroke Organisation (ESO) guidelines on mobile stroke units for prehospital stroke management

The safety and efficacy of mobile stroke units (MSUs) in prehospital stroke management has recently been investigated in different clinical studies. MSUs are ambulances equipped with a CT scanner, point-of-care lab, telemedicine and are staffed with a stroke specialised medical team. This European Stroke Organisation (ESO) guideline provides an up-to-date evidence-based recommendation to assist decision-makers in their choice on using MSUs for prehospital management of suspected stroke, which includes patients with acute ischaemic stroke (AIS), intracranial haemorrhage (ICH) and stroke mimics. The guidelines were developed according to the ESO standard operating procedure and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology. The working group identified relevant clinical questions, performed systematic reviews and aggregated data meta-analyses of the literature, assessed the quality of the available evidence and made specific recommendations. Expert consensus statements are provided where sufficient evidence was not available to provide recommendations based on the GRADE approach. We found moderate evidence for suggesting MSU management for patients with suspected stroke. The patient group diagnosed with AIS shows an improvement of functional outcomes at 90 days, reduced onset to treatment times and increased proportion receiving IVT within 60 min from onset. MSU management might be beneficial for patients with ICH as MSU management was associated with a higher proportion of ICH patients being primarily transported to tertiary care stroke centres. No safety concerns (all-cause mortality, proportion of stroke mimics treated with IVT, symptomatic intracranial bleeding and major extracranial bleeding) could be identified for all patients managed with a MSU compared to conventional care. We suggest MSU management to improve prehospital management of suspected stroke patients.

Comparison of Mobile Stroke Unit With Usual Care for Acute Ischemic Stroke Management: A Systematic Review and Meta-analysis

IMPORTANCE

So far, uncertainty remains as to whether there is sufficient cumulative evidence that mobile stroke unit (MSU; specialized ambulance equipped with computed tomography scanner, point-of-care laboratory, and neurological expertise) use leads to better functional outcomes compared with usual care.

OBJECTIVE

To determine with a systematic review and meta-analysis of the literature whether MSU use is associated with better functional outcomes in patients with acute ischemic stroke (AIS).

DATA SOURCES

MEDLINE, Cochrane Library, and Embase from 1960 to 2021.

STUDY SELECTION

Studies comparing MSU deployment and usual care for patients with suspected stroke were eligible for analysis, excluding case series and case-control studies.

DATA EXTRACTION AND SYNTHESIS

Independent data extraction by 2 observers, following the PRISMA and MOOSE reporting guidelines. The risk of bias in each study was determined using the ROBINS-I and RoB2 tools. In the case of articles with partially overlapping study populations, unpublished disentangled results were obtained. Data were pooled in random-effects meta-analyses.

MAIN OUTCOMES AND MEASURES

The primary outcome was excellent outcome as measured with the modified Rankin Scale (mRS; score of 0 to 1 at 90 days).

RESULTS

Compared with usual care, MSU use was associated with excellent outcome (adjusted odds ratio [OR], 1.64; 95% CI, 1.27-2.13; P < .001; 5 studies; n = 3228), reduced disability over the full range of the mRS (adjusted common OR, 1.39; 95% CI, 1.14-1.70; P = .001; 3 studies; n = 1563), good outcome (mRS score of 0 to 2: crude OR, 1.25; 95% CI, 1.09-1.44; P = .001; 6 studies; n = 3266), shorter onset-to-intravenous thrombolysis (IVT) times (median reduction, 31 minutes [95% CI, 23-39]; P < .001; 13 studies; n = 3322), delivery of IVT (crude OR, 1.83; 95% CI, 1.58-2.12; P < .001; 7 studies; n = 4790), and IVT within 60 minutes of symptom onset (crude OR, 7.71; 95% CI, 4.17-14.25; P < .001; 8 studies; n = 3351). MSU use was not associated with an increased risk of all-cause mortality at 7 days or at 90 days or with higher proportions of symptomatic intracranial hemorrhage after IVT.

CONCLUSIONS AND RELEVANCE

Compared with usual care, MSU use was associated with an approximately 65% increase in the odds of excellent outcome and a 30-minute reduction in onset-to-IVT times, without safety concerns. These results should help guideline writing committees and policy makers.

Mobile stroke care expedites intravenous thrombolysis and endovascular thrombectomy

BACKGROUND

The number of mobile stroke programmes has increased with evidence, showing they expedite intravenous thrombolysis. Outstanding questions include whether time savings extend to patients eligible for endovascular therapy and impact clinical outcomes.

OBJECTIVE

Our mobile stroke unit (MSU), based at an academic medical centre in upstate New York, launched in October 2018. We reviewed prospective observational data sets over 26 months to identify MSU and non-MSU emergency medical service (EMS) patients who underwent intravenous thrombolysis or endovascular thrombectomy for comparison of angiographic and clinical outcomes.

RESULTS

Over 568 days in service, the MSU was dispatched 1489 times (2.6/day) and transported 300 patients (20% of dispatches). Intravenous tissue plasminogen activator (tPA) was administered to 57 MSU patients and the average time from 911 call-to-tPA was 42.5 min (±9.2), while EMS transported 73 patients who received tPA at 99.4 min (±35.7) (p<0.001). Seven MSU patients (12%) received tPA from 3.5 hours to 4.5 hours since last known well and would likely have been outside the window with EMS care. Endovascular thrombectomy was performed on 21 MSU patients with an average 911 call-to-groin puncture time of 99.9 min (±18.1), while EMS transported 54 patients who underwent endovascular thrombectomy (ET) at 133.0 min (±37.0) (p=0.0002). There was no difference between MSU and traditional EMS in modified Rankin score at 90-day clinic follow-up for patients undergoing intravenous thrombolysis or endovascular thrombectomy, whether assessed as a dichotomous or ordinal variable.

CONCLUSIONS

Mobile stroke care expedited both intravenous thrombolysis and endovascular thrombectomy. There is an ongoing need to show improved functional outcomes with MSU care.

Detection and vascular territorial classification of stroke on diffusion-weighted MRI by deep learning

PURPOSE

Rapid detection and vascular territorial classification of stroke enable the determination of the most appropriate treatment. In this study, we aimed to investigate the performance of convolutional neural network (CNN) models in the detection and vascular territorial classification of stroke on diffusion-weighted images (DWI).

METHODS

DWI of 421 cases (271 acute ischemic stroke patients and 150 cases without any ischemia findings on DWI) obtained between January 2017 to April 2020 were reviewed. We created two custom datasets. A stroke detection dataset was created with 1800 slices (900 S and 900 normal) consisting of 1400 for training, 200 for validation, 200 for test. A vascular territorial type dataset was created with 1717 slices (883 middle cerebral artery stroke, 416 posterior circulatory stroke, and 418 watershed stroke) consisting of 1117 slices for training, 300 for validation, 300 for test. A transfer learning approach based on MobileNetV2 and EfficientNet-B0 CNN architecture was used. The performance of the models was evaluated.

RESULTS

Modified MobileNetV2 and EfficientNet-B0 models achieved 96% (κ: 0.92) and 93% (κ: 0.86) accuracy in stroke detection, respectively. In vascular territorial classification of stroke as middle cerebral artery, posterior circulation, or watershed infarction, an accuracy of 93% (κ: 0.895) was achieved with modified MobileNetV2 model and 87% (κ: 0.805) with modified EfficientNet-B0 CNN model.

CONCLUSION

Transfer learning approach with custom top CNN models achieve sufficiently high performance for both the detection of ischemic stroke and the classification of its vascular territorial type on DWI.

Identifying patients with cerebral infarction within the time window compatible with reperfusion therapy, diagnostic performance of glutathione S-transferase-π (GST-π) and peroxiredoxin 1 (PRDX1): exploratory prospective multicentre study FLAG-1 protocol

INTRODUCTION

Plasma biomarkers may be useful in diagnosing acute cerebral infarction requiring urgent reperfusion, but their performance remains to be confirmed. If confirmed, these molecules could be used to develop rapid and reliable decentralised measurement methods, making it possible to initiate reperfusion therapy before hospital admission. The FLAG-1 large prospective study will constitute a plasma bank to assess the diagnostic performance of two biomarkers: glutathione S-transferase-π and peroxiredoxin 1. These molecules are involved in the oxidative stress response and could identify cerebral infarction within a therapeutic window of less than 4.5 hours following the onset of symptoms. Secondary objectives include assessing performance of these biomarkers within 3-hour and 6-hour windows; identifying additional biomarkers diagnosing cerebral infarction and significant criteria guiding therapeutic decisions: ischaemic features of stroke, presence of diffusion/fluid-attenuated inversion recovery mismatch, volume of cerebral infarction and penumbra on cerebral MRI.

METHODS AND ANALYSIS

The exploratory, prospective, multicentre FLAG-1 Study will include 945 patients with acute stroke symptoms (onset ≤12 hours, National Institute of Health Stroke Scale score ≥3). Each patient's 25 mL blood sample will be associated with cerebral MRI data. Two patient groups will be defined based on the time of blood collection (before and after 4.5 hours following onset). Receiver operating characteristic analysis will determine the diagnostic performance of each biomarker, alone or in combination, for the identification of cerebral infarction <4.5 hours.

ETHICS AND DISSEMINATION

The protocol has been approved by an independent ethics committee. Biological samples are retained in line with best practices and procedures, in accordance with French legislation. Anonymised data and cerebral imaging records are stored using electronic case report forms and a secure server, respectively, registered with the French Data Protection Authority (Commission Nationale de l'Informatique et des Libertés (CNIL)). Results will be disseminated through scientific meetings and publication in peer-reviewed medical journals.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT03364296).

Digital health in stroke medicine: what are the opportunities for stroke patients?

PURPOSE OF REVIEW

The European Stroke Organisation published a European Stroke Action Plan (SAP-E) for the years 2018-2030. The SAP-E addresses the entire chain of care from primary prevention through to life after stroke. Within this document digital health tools are suggested for their potential to facilitate greater access to stroke care. In this review, we searched for digital health solutions for every domain of the SAP-E.

RECENT FINDINGS

Currently available digital health solutions for the cerebrovascular disease have been designed to support professionals and patients in healthcare settings at all stages. Telemedicine in acute settings has notably increased the access to tissue plasminogen activator and thrombectomy whereas in poststroke settings it has improved access to rehabilitation. Moreover, numerous applications aim to monitor vital signs and prescribed treatment adherence.

SUMMARY

SAP-E with its seven domains covers the whole continuum of stroke care, where digital health solutions have been considered to provide utility at a low cost. These technologies are progressively being used in all phases of stroke care, allowing them to overcome geographical and organizational barriers. The commercially available applications may also be used by patients and their careers in various context to facilitate accessibility to health improvement strategies.

Interhospital Transfer of Patients With Acute Pulmonary Embolism (PE): Challenges and Opportunities

Acute pulmonary embolism (PE) is associated with significant morbidity and mortality. The management paradigm for acute PE has evolved in recent years with wider availability of advanced treatment modalities ranging from catheter-directed reperfusion therapies to mechanical circulatory support. This evolution has coincided with the development and implementation of institutional pulmonary embolism response teams (PERT) nationwide and internationally. Because most institutions are not equipped or staffed for advanced PE care, patients often require transfer to centers with more comprehensive resources, including PERT expertise. One of the unmet needs in current PE care is an organized approach to the process of interhospital transfer (IHT) of critically ill PE patients. In this review, we discuss medical optimization and support of patients before and during transfer, transfer checklists, defined roles of emergency medical services, and the roles and responsibilities of referring and receiving centers involved in the IHT of acute PE patients.

Application of Mobile Stroke Unit in Prehospital Thrombolysis of Acute Stroke: Experience from China

BACKGROUND AND PURPOSE

Most patients cannot receive intravenous thrombolytic therapy in the early stage of stroke onset, and the application of mobile stroke unit (MSU) in prehospital intravenous thrombolytic therapy of acute stroke may change this situation. The first MSU in China was put into use in 2017. Herein, we aimed to explore the preliminary experience of MSU in prehospital thrombolysis of acute stroke.

METHODS

Patients who received prehospital intravenous thrombolytic therapy using MSU were classified to the MSU thrombolysis group, and the control group consisted of stroke patients admitted by regular ambulances, who were transferred to hospital for intravenous thrombolytic therapy. The feasibility, safety, and duration of procedures were compared.

RESULTS

There were 14 patients received prehospital intravenous thrombolysis on the MSU, and 24 patients underwent intravenous thrombolysis in the emergency center, who were transferred by the ordinary ambulance during the same period. The median call-to-needle time was 59.5 min in the MSU thrombolysis group, while it was 89 min in the control group; the difference between the 2 groups was statistically significant (p = 0.001). The median time from onset to thrombolysis was 70 and 102.5 min, respectively, in the 2 groups (p = 0.002). The percentages of good clinical outcome (modified Rankin Scale score ≤ 2) at 90-day follow-up were 79 and 67%, respectively (p = 0.488). The rate of symptomatic intracranial hemorrhage and mortality during the perioperative period did not differ significantly between 2 groups.

CONCLUSION

Despite the small sample size, our preliminary experience of the application of MSU in the prehospital thrombosis therapy seems to indicate a significant reduction in time from call to needle, the efficacy of MSU in the treatment of acute stroke needs further experiment and larger sample size to confirm.

Impact of mobile stroke units

Since its first introduction in clinical practice in 2008, the concept of mobile stroke unit enabling prehospital stroke treatment has rapidly expanded worldwide. This review summarises current knowledge in this young field of stroke research, discussing topics such as benefits in reduction of delay before treatment, vascular imaging-based triage of patients with large-vessel occlusion in the field, differential blood pressure management or prehospital antagonisation of anticoagulants. However, before mobile stroke units can become routine, several questions remain to be answered. Current research, therefore, focuses on safety, long-term medical benefit, best setting and cost-efficiency as crucial determinants for the sustainability of this novel strategy of acute stroke management.

A Comparison of Time to Treatment between an Emergency Department Focused Stroke Protocol and Mobile Stroke Units

BACKGROUND

San Francisco (California USA) is a relatively compact city with a population of 884,000 and nine stroke centers within a 47 square mile area. Emergency Medical Services (EMS) transport distances and times are short and there are currently no Mobile Stroke Units (MSUs).

METHODS

This study evaluated EMS activation to computed tomography (CT [EMS-CT]) and EMS activation to thrombolysis (EMS-TPA) times for acute stroke in the first two years after implementation of an emergency department (ED) focused, direct EMS-to-CT protocol entitled "Mission Protocol" (MP) at a safety net hospital in San Francisco and compared performance to published reports from MSUs. The EMS times were abstracted from ambulance records. Geometric means were calculated for MP data and pooled means were similarly calculated from published MSU data.

RESULTS

From July 2017 through June 2019, a total of 423 patients with suspected stroke were evaluated under the MP, and 166 of these patients were either ultimately diagnosed with ischemic stroke or were treated as a stroke but later diagnosed as a stroke mimic. The EMS and treatment time data were available for 134 of these patients with 61 patients (45.5%) receiving thrombolysis, with mean EMS-CT and EMS-TPA times of 41 minutes (95% CI, 39-43) and 63 minutes (95% CI, 57-70), respectively. The pooled estimates for MSUs suggested a mean EMS-CT time of 35 minutes (95% CI, 27-45) and a mean EMS-TPA time of 48 minutes (95% CI, 39-60). The MSUs achieved faster EMS-CT and EMS-TPA times (P <.0001 for each).

CONCLUSIONS

In a moderate-sized, urban setting with high population density, MP was able to achieve EMS activation to treatment times for stroke thrombolysis that were approximately 15 minutes slower than the published performance of MSUs.

Imaging of Spontaneous Intracerebral Hemorrhage

Primary or nontraumatic spontaneous intracerebral hemorrhage (ICH) comprises approximately 15% to 20% of all stroke. ICH has a mortality of approximately 40% within the first month, and 75% mortality and morbidity rate within the first year. Despite reduction in overall stroke incidence, hemorrhagic stroke incidence has remained steady since 1980. Neuroimaging is critical in detection of ICH, determining the underlying cause, identification of patients at risk of hematoma expansion, and directing the treatment strategy. This article discusses the neuroimaging methods of ICH, imaging markers for clinical outcome prediction, and future research directions with attention to the latest evidence-based guidelines.

Pre-hospital triage of suspected acute stroke patients in a mobile stroke unit in the rural Alberta

Mobile Stroke Unit (MSU) expedites the delivery of intravenous thrombolysis in acute stroke patients. We further evaluated the functional outcome of patients shipped to a tertiary care centre or repatriated to local hospitals after triage by MSU in acute stroke syndrome in rural northern Alberta. Consecutive patients with suspected acute stroke syndrome were included. On the basis of neurology consultation and, Computed Tomography findings, patients, who were thrombolysed or needed advanced care were transported to the Comprehensive stroke center (CSC) (Triage to CSC group). Other patients were repatriated to local hospital care (Triage to LHC group). A total of 156 patients were assessed in MSU, 73 (46.8%) were female and the mean age was 66.6 ± 15 years. One hundred and eight (69.2%) patients, including 41 (26.3%) treated with thrombolysis were transported to the CSC (Triage to CSC group) and 48 (30.8%) were repatriated to local hospital care. The diagnosis made in MSU and final diagnosis were matching in 88% (95) and 91.7% (44, p = 0.39) in Triage to CSC and Triage to LHC groups respectively. Prehospital triage by MSU of acute stroke syndrome can reliably repatriate patients to the home hospital. The proposed model has the potential to triage patients according to their medical needs by enabling treatment in home hospitals whenever reasonable.

Evaluation of carbon nanotube x-ray source array for stationary head computed tomography

PURPOSE

Stationary computed tomography (s-CT) conceptually offers several advantages over existing rotating gantry-based CT. Over the last 40 yr, s-CT has been investigated using different technological approaches. We are developing a s-CT system specifically for head/brain imaging using carbon nanotube (CNT)-based field emission x-ray source array technology. The noncircular geometry requires different assessment approaches as compared to circular geometries. The purpose of the present study is to investigate whether the CNT source array meets the requirements for stationary head CT (s-HCT).

METHODS

Multiple prototype CNT x-ray source arrays were manufactured based on the system requirements obtained from simulation. Source characterization was performed using a benchtop setup consisting of an x-ray source array with 45 distributed focal spots, each operating at 120 kVp, and an electronic control system (ECS) for high speed control of the x-ray output from individual focal spots. Due to the forward-angled geometry of the linear anode, the projected focal spot shape is expected to vary at wide angle views. A pinhole method was implemented to determine the effective focal spot size (FSS) in the imaging plane at a range of angular viewpoints with a flat panel detector. The output spectrum and half value layer (HVL) were also evaluated for a range of viewing angles to characterize the beam quality across the fan-beam. Dosimetry was performed on a simulated scan to evaluate total exposure.

RESULTS

The prototype CNT x-ray source array demonstrated adequate specifications for a s-HCT imaging machine. The source array was operated at 120 kVp with long-term stability over a full year of regular laboratory use. Multiple cathode current measurements were used to confirm submicrosecond accuracy with regards to exposure time and subsequently dose control. All 45 focal spots were measured with an average value of 1.26 (±0.04) mm × 1.21 (±0.03) mm (equivalent to IEC 1,0). The x-ray spectrum was found to be appropriately filtered based on sources used in existing rotary CT systems. A stable and reliable output of 0.04 mAs per emitter and a resulting dose of 0.015 mGy per projection were observed over several months of rigorous phantom imaging. Dose per projection was regulated by the ECS and measured with ±0.5% tolerance.

CONCLUSIONS

The CNT x-ray source array was found to meet the requirements for the proposed stationary head CT scanner, with regard to FSS, beam quality, and dose precision. The remaining challenges are related to the overall system design of a nonrotating CT scanner with distributed sources. The next phase of the project will incorporate multiple CNT source arrays with multirow detectors in a proof-of-concept study and analysis of a fully functional s-HCT system.

Mobile Stroke Units: Current and Future Impact on Stroke Care

Ischemic stroke is a leading cause of death and major disability that impacts societies across the world. Earlier thrombolysis of blocked arteries with intravenous tissue plasminogen activator (tPA) and/or endovascular clot extraction is associated with better clinical outcomes. Mobile stroke units (MSU) can deliver faster tPA treatment and rapidly transport stroke patients to centers with endovascular capabilities. Initial MSU trials in Germany indicated more rapid tPA treatment times using MSUs compared with standard emergency room treatment, a higher proportion of patients treated within 60 minutes of stroke onset, and a trend toward better 3-month clinical outcomes with MSU care. In the United States, the first multicenter, randomized clinical trial comparing standard versus MSU treatment began in 2014 in Houston, TX, and has demonstrated feasibility and safety of MSU operations, reliability of telemedicine technology to assess patients for tPA eligibility without additional time delays, and faster door-to-groin puncture times of MSU patients needing endovascular thrombectomy in interim analysis. Scheduled for completion in 2021, this trial will determine the cost-effectiveness and benefit of MSU treatment on clinical outcomes compared with standard ambulance and hospital treatment. Beyond ischemic stroke, MSUs have additional clinical and research applications that can profoundly impact other cohorts of patients who require time-sensitive neurological care.

Probability assessment of intracerebral hemorrhage in prehospital emergency patients

BACKGROUND

Routing of patients with intracerebral hemorrhage (ICH) and acute ischemic stroke (AIS) to the most appropriate hospital is challenging for emergency medical services particularly when specific treatment options are only provided by specialized hospitals and determination of the exact diagnosis is difficult. We aimed to develop a prehospital score - called prehospital-intracerebral hemorrhage score (ph-ICH score) - to assist in discriminating between both conditions.

METHODS

The ph-ICH score was developed with data from patients treated aboard a mobile stroke unit in Berlin, Germany, between 2011 and 2013 (derivation cohort) and in 2018 (validation cohort). Diagnosis of ICH or AIS was established using clinical data and neuroradiological cerebral imaging. Diagnostic accuracy was measured with significance testing, Cohen's d and receiver-operating-characteristics.

RESULTS

We analyzed 416 patients (32 ICH, 224 AIS, 41 transient ischemic attack, 119 stroke mimic) in the derivation cohort and 285 patients (33 ICH and 252 AIS) in the validation cohort. Systolic blood pressure, level of consciousness and severity of neurological deficits (i. e. certain items of the National Institutes of Health Stroke Scale) were used to calculate the ph-ICH score that showed higher values in the ICH compared to the AIS group (derivation cohort: 1.8 ± 1.2 vs. 1.0 ± 0.9 points; validation cohort: 1.8 ± 0.9 vs. 0.8 ± 0.7 points; d = 0.9 and 1.4, both p < 0.01). Receiver-operating-characteristics showed fair and good accuracy with an area under the curve of 0.71 for the derivation and 0.81 for the validation cohort.

CONCLUSIONS

The ph-ICH score can assist medical personnel in the field to assess the likelihood of ICH and AIS in emergency patients.

Stroke systems of care in high-income countries: what is optimal?

Stroke is a complex, time-sensitive, medical emergency that requires well functioning systems of care to optimise treatment and improve patient outcomes. Education and training campaigns are needed to improve both the recognition of stroke among the general public and the response of emergency medical services. Specialised stroke ambulances (mobile stroke units) have been piloted in many cities to speed up the diagnosis, triage, and emergency treatment of people with acute stroke symptoms. Hospital-based interdisciplinary stroke units remain the central feature of a modern stroke service. Many have now developed a role in the very early phase (hyperacute units) plus outreach for patients who return home (early supported discharge services). Different levels (comprehensive and primary) of stroke centre and telemedicine networks have been developed to coordinate the various service components with specialist investigations and interventions including rehabilitation. Major challenges include the harmonisation of resources for stroke across the whole patient journey (including the rapid, accurate triage of patients who require highly specialised treatment in comprehensive stroke centres) and the development of technology to improve communication across different parts of a service.

Telemedicine in Prehospital Acute Stroke Care

Background

Mobile stroke units (MSUs), equipped with an integrated computed tomography scanner, can shorten time to thrombolytic treatment and may improve outcome in patients with acute ischemic stroke. Original (German) MSUs are staffed by neurologists trained as emergency physicians, but patient assessment and treatment decisions by a remote neurologist may offer an alternative to neurologists aboard MSU.

Methods and Results

Remote neurologists examined and assessed emergency patients treated aboard the MSU in Berlin, Germany. Audiovisual quality was rated by the remote neurologist from 1 (excellent) to 6 (insufficient), and duration of video examinations was assessed. We analyzed interrater reliability of diagnoses, scores on the National Institutes of Health Stroke Scale and treatment decisions (intravenous thrombolysis) between the MSU neurologist and the remote neurologist. We included 90 of 103 emergency assessments (13 patients were excluded because of either failed connection, technical problems, clinical worsening during teleconsultation, or missing data in documentation) in this study. The remote neurologist rated audiovisual quality with a median grade for audio quality of 3 (satisfactory) and for video quality of 2 (good). Mean time for completion of teleconsultations was about 19±5 minutes. The interrater reliabilities between the onboard and remote neurologist were high for diagnoses (Cohen's κ=0.86), National Institutes of Health Stroke Scale sum scores (intraclass correlation coefficient, 0.87) and treatment decisions (16 treatment decisions agreed versus 2 disagreed; Cohen's κ=0.93).

Conclusions

Remote assessment and treatment decisions of emergency patients are technically feasible with satisfactory audiovisual quality. Agreement on diagnoses, neurological examinations, and treatment decisions between onboard and remote neurologists was high.

See Editorial by Derry et al

Mobile stroke unit versus standard medical care in the management of patients with acute stroke: A systematic review and meta-analysis

INTRODUCTION

Mobile stroke units have recently been introduced in the care of patients suspected of having an acute stroke, leading to shortening in the time to thrombolytics. We aimed to compare the clinical effectiveness in terms of functional outcome and survival among patients treated in mobile stroke unit and/or conventional care.

METHODS

A systematic search of electronic databases, comparing the clinical outcomes among patients with acute stroke in the same study was conducted from 1990 to 2019. Pooled and subgroup analysis were performed using the random- and fixed-effect model based upon the I² heterogeneity.

RESULTS

A total of 21,297 patients from 11 publications (seven randomized controlled trials and four non-randomized controlled trials including prospective cohort studies) were retrieved. This included 6065 (n = 28.4%) of the patients treated in the mobile stroke unit and 71.6% (n = 15,232) of the patients managed in the conventional care. The mean age at clinical presentation (70.1 ± 14.5 vs. 71.05 ± 15.8) and National Institute Health Stroke Scale (9.8 ± 1.7 vs. 8.4 ± 1.5) was comparable (p > 0.05) in patients treated with mobile stroke unit and conventional care, respectively. The mean time-to-treatment window was significantly shorter among the patients treated in mobile stroke unit compared to conventional care (62.0 min vs. 75.0 min; p = 0.03, respectively). The pooled analysis of clinical outcome at day 7 indicated that patients treated in mobile stroke unit had 1.46-folds higher likelihood of better clinical outcome (modified Rankin scale 0-2) than those in the hospital (odds ratio: 1.46, 95% confidence interval: 1.306-2.03, p = 0.02). However, there was no significant difference in terms of mortality (odds ratio: 0.98, 95% confidence interval: 0.81-1.18, p = 0.80), stroke-related neurological deficits (odds ratio: 1.37, 95% confidence interval: 0.81-2.32, p = 0.24), and other serious adverse events (odds ratio: 0.69, 95% confidence interval: 0.39-1.20, p = 0.19) among patients treated in mobile stroke unit versus conventional care.

CONCLUSION

Our results corroborate that patients treated in mobile stroke unit lead to short-term recovery following acute stroke without influencing the mortality rate. Further prospective studies are needed to validate our results.

In What Scenarios Does a Mobile Stroke Unit Predict Better Patient Outcomes?: A Modeling Study

Background and Purpose- The mobile stroke unit (MSU) brings imaging and thrombolysis to patients in the field. The MSU has the potential to decrease time from onset to thrombolysis; however, this depends on the location of the patient, the MSU, and the hospital. The MSU will only be able to treat a small subset of patients it is dispatched to. Using conditional probability modeling, we evaluate in which scenarios the MSU exhibits clear benefit over the direct-to-mothership method. Methods- Previously published conditional probability models for drip-and-ship versus mothership transport were modified to reflect MSU workflow. It was assumed that the MSU was dispatched from the endovascular therapy center. Eight scenarios were generated, varying treatment efficiency on the MSU and at the endovascular therapy center and the threshold for dispatching the MSU (low threshold: low treatment rate but few missed patients; high threshold: higher treatment rate, potential for missed treatment opportunities). Results- The relative difference in outcomes between the MSU and mothership was small. Geographic areas where the MSU is superior to mothership increase in size as treatment time on the MSU decreases. When a high-threshold dispatch system is used, the area where the MSU is superior decreases, but the relative difference in predicted outcomes between the MSU and mothership increases. The largest relative difference favoring the MSU was found in areas where the patient would forgo access to alteplase, based upon a 4.5-hour treatment threshold, using mothership transport. Conclusions- There are few scenarios where MSU transport predicts substantially superior outcomes to the mothership method when the MSU is dispatched from the endovascular therapy center. Outcomes using the MSU are maximized when dispatch criteria that maximize patients eligible for thrombolysis treatment are used and treatment times on the MSU are short relative to those of the endovascular therapy center.

Mobile Stroke Units: Bringing Treatment to the Patient

PURPOSE OF REVIEW

Mobile stroke units (MSUs) have revolutionized emergency stroke care by delivering pre-hospital thrombolysis faster than conventional ambulance transport and in-hospital treatment. This review discusses the history of MSUs technological development, current operations and research, cost-effectiveness, and future directions.

RECENT FINDINGS

Multiple prospective and retrospective studies have shown that MSUs deliver acute ischemic stroke treatment with intravenous recombinant tissue plasminogen activator (IV r-tPA) approximately 30 min faster than conventional care. The 90-day modified Rankin Scores for patients who received IV r-tPA on the MSU compared to conventional care were not statistically different in the PHANTOM-S study. Two German studies suggest that the MSU model is cost-effective by reducing disability and improving adjusted quality-life years post-stroke. The ongoing BEST-MSU trial will be the first multicenter, randomized controlled study that will shed light on MSUs' impact on long-term neurologic outcomes and cost-effectiveness. MSUs are effective in reducing treatment times in acute ischemic stroke without increasing adverse events. MSUs could potentially improve treatment times in large vessel occlusion and intracranial hemorrhage. Further studies are needed to assess functional outcomes and cost-effectiveness. Clinical trials are ongoing internationally.

Pre-hospital Assessment of Large Vessel Occlusion Strokes: Implications for Modeling and Planning Stroke Systems of Care

The social and financial burden of stroke is remarkable. Stroke is a leading cause of death and long-term disability worldwide. For several years, intravenous recombinant tissue plasminogen activator (IV rt-PA) remained as the only proven therapy for acute ischemic stroke. However, its benefit is hampered by a narrow therapeutic window and limited efficacy for large vessel occlusion (LVO) strokes. Recent trials of endovascular therapy (EVT) for LVO strokes have demonstrated improved patient outcomes when compared to treatment with medical treatment alone (with or without IV rt-PA). Thus, EVT has become a critical component of stroke care. As in IV rt-PA, time to treatment is a crucial factor with high impact on outcomes. Unlike IV rt-PA, EVT is only available at a limited number of centers. Considering the time sensitive benefit of reperfusion therapies of acute ischemic stroke, costs and logistics associated, it is recommended that regional systems of acute stroke care should be developed. These should include rapid identification of suspected stroke, centers that provide initial emergency care, including administration of IV rt-PA, and centers capable of performing endovascular stroke treatment with comprehensive periprocedural care to which rapid transport can be arranged when appropriate. In the pre-hospital setting, the development of scales easier and quicker to perform than the NIHSS yet with a maintained accuracy for detecting LVO strokes is of paramount importance. Several scales have been developed. On the other hand, the decision whether to transport to a primary stroke center (PSC) or to a comprehensive stroke center (CSC) is complex and far beyond the simple diagnosis of a LVO. Ongoing studies will provide important answers to the best transfer strategy for acute stroke patients. At the same time, the development of new technologies to aid in real time the decision-making process will simplify the logistics of regional systems for acute stroke care and, likely improve patients' outcomes through tailored selection of the most appropriate recanalization strategy and destination center.

Functional stroke outcomes after mobile stroke unit deployment - the revised protocol for the Berlin Prehospital Or Usual Delivery of acute stroke care (B_PROUD) part 2 study

Background

Studies investigating the Mobile Stroke Unit (MSU) concept have shown increased thrombolysis rates, reduced alarm-to-treatment times and improved prehospital triage. Yet, so far, there is no definite scientific proof of better functional outcome after MSU deployment compared to regular ambulances.

Methods

We provide a revised protocol for the second part of the B_PROUD trial as organization of the MSU dispatch did not meet the anticipated standards in the first part. B_PROUD is a pragmatic, prospective study comparing functional outcomes of treatment candidates with or without MSU care. Treatment candidates are defined as patients with a final diagnosis of ischemic stroke or transient ischemic attack, onset-to-dispatch-times ≤4 h, disabling symptoms not resolved at time of ambulance arrival, and the ability to ambulate prior to the qualifying event. These patients are included if their emergency call prompted a stroke alarm at the dispatch center during MSU operation hours (7 am–11 pm, Monday-Sunday) and if the emergency is located within the MSU operation area in Berlin, Germany. The intervention group consists of patients who are cared for by the MSU. When the MSU is already in operation for another emergency, MSU dispatches are handled by regular ambulances (about 45%). These dispatches create the control group. Blinded stroke physicians assess the modified Rankin Scale (mRS) score in recorded structured interviews 3 months after stroke. The primary outcome is the degree of disability and death over the full range of the mRS. As a change to the previously published protocol and only pertinent in case of more than 9% lost-to-follow-up, a co-primary outcome was introduced consisting of the proportions of death, new institutional care or severe disability in patients with additional use of information from registration offices.

Perspective

The results will inform parties involved in acute stroke care organization on the effectiveness of the MSU concept.

Trial registration

The protocol is registered in (NCT03931616) and has been approved by the ethical review committee of the Charité – University Medicine Berlin (EA4/109/15) on September 2, 2015. The study protocol of B_PROUD part 1 had been published in the International Journal of Stroke as “Berlin Prehospital Or Usual Delivery of acute stroke care (B_PROUD) – study protocol” (doi: 10.1177/1747493017700152) on March 22, 2017 [1] previous to first patient’s registration.

Pre-hospital management of acute stroke patients eligible for thrombolysis - an evaluation of ambulance on-scene time

BACKGROUND

Stroke is a leading cause of death and disability with effective treatment, including thrombolysis or thrombectomy, being time-critical for favourable outcomes. While door-to-needle time in hospital has been optimized for many years, little is known about the ambulance on-scene time (OST). OST has been reported to account for 44% of total alarm-to-door time, thereby being a major time component. We aimed to analyse ambulance OST in stroke patients eligible for thrombolysis and identify potential areas of time optimization.

METHODS

A study-specific registration form was developed to record detailed information about OST consumption in cases where the Emergency Medical Services (EMS) suspected a stroke from July 2014-May 2015. Registration forms were completed by ambulance personnel and included details on estimated time spent: 1) localising patient, 2) clinical examination, 3) consulting with the on-call neurologist, 4) mobilising patient to the ambulance, 5) treatment in ambulance before departure. Additionally, estimated total OST was noted. For patients found eligible for further evaluation at a stroke centre, time points were analysed using multivariate Poisson regressions.

RESULTS

A total of 520 cases were included. The median OST was 21 min (Interquartile Range (IQR) 16-27). Time consumption was significantly lower (17 vs 21 min, p = 0.0015) when electrocardiography (ECG) was obtained in-hospital instead of on-scene, when intravenous (IV) access was established during transportation instead of before transportation (17 vs 21 min, p < 0.0001), and when the quality of communication with the stroke centres was rated as "good" as opposed to "acceptable/poor" (21 vs 23 min, p = 0.014). Neither the presence of relatives nor ambulance trainees had a significant effect on OST.

CONCLUSIONS

In-hospital ECG recording and IV cannulation during transport were found to reduce OST, while "acceptable/poor" communication was found to prolong OST relative to "good" communication. These components of pre-hospital stroke management represent potential opportunities for lowering OST with relatively simple changes, which could ultimately lead to earlier treatment and better patient outcome.

TRIAL REGISTRATION

Unique identifier: NCT02191514 .

Evaluation of a score for the prehospital distinction between cerebrovascular disease and stroke mimic patients

Background

Patients with a sudden onset of focal neurological deficits consistent with stroke, who turn out to have alternative conditions, have been labeled stroke mimics.

Aims

We assessed a recently validated telemedicine-based stroke mimic score (TeleStroke mimic score; TM-score) and individual patient characteristics with regard to its discriminative value between cerebrovascular disease and stroke mimic patients in the in-person, pre-hospital setting.

Methods

We evaluated patients cared for in a mobile stroke unit in Berlin, Germany. We investigated whether the TM-score (comprising six parameters), Face Arm Speech Time test, and individual patient characteristics were able to differentiate cerebrovascular disease from stroke mimic patients.

Results

We included 423 patients (299 (70.7%) cerebrovascular disease and 124 (29.3%) stroke mimic) in the final analysis. A TM-score > 30 indicated a high probability of a cerebrovascular disease and a score ≤15 of a stroke mimic. The TM-score performed well to identify stroke mimics (area under the curve of 0.74 under receiver-operating characteristic curve analysis). The cerebrovascular disease patients were older (74.8 vs. 69.8 years, p = 0.001), had more often severe strokes (NIHSS > 14 25.8% vs. 11.3%, p = 0.001), presented more often with weakness of the face (70.9% vs. 42.7%, p = 0.001) or arm (60.9% vs. 33.9%, p = 0.001), dysarthria (59.5% vs. 40.3%, p < 0.001), history of atrial fibrillation (38.1% vs. 21.0%, p = 0.001), arterial hypertension (78.9% vs. 53.2%, p < 0.001), and less often with seizure (0.7% vs. 21.0%, p < 0.001).

Conclusions

The TM-score and certain patient characteristics can help paramedics and emergency physicians in the field to identify stroke mimic patients and select the most appropriate hospital destination.

A History of Mobile Stroke Units and Review of Literature

Using intravenous tissue plasminogen activator (IV tPA), improved functional outcomes are seen with earlier initiation of treatment. Recent studies have shown endovascular revascularization to be a revolutionary and effective treatment. There have been many initiatives focused on improving public education and awareness of stroke symptoms. The concept of a mobile stroke unit (MSU) was created as a way of bringing treatment to patients. Earlier CT scans, delivery of tPA, proper triage and on-scene goal-directed care were the primary goals with these units. It was thought that rapid implementation would shorten hospital stay and improve outcomes. The University of Saarland found a decrease of 41 minutes from stroke alarm to therapeutic decision when an MSU was used. A second trial found a decrease of 25 minutes in time to treatment, an increase in the rate of thrombolysis utilization, and no change in the rates of intracranial hemorrhage or 7-day mortality when an MSU was employed. In 2016, a Lancet article showed that 3 month modified Rankin Scale (mRS) and 3-month mortality were improved in MSU patients. Finally, starting thrombolytic therapy in the MSU was associated with higher probability of mRS of 0-3 but not an improved 3-month survival rate. Long-term results are thus far not available precluding an effective cost-benefit analysis. Many study results are not generalizable as they compare a single hospital system and specialized MSU team to conventional care delivered by a multiple healthcare systems. Future studies will target these limitations.

Review of the Mobile Stroke Unit Experience Worldwide

Background

The treatment of stroke is dependent on a narrow therapeutic time window that requires interventions to be emergently pursued. Despite recent "FAST" initiatives that have underscored "time is brain," many patients still fail to present within the narrow time window to receive maximum treatment benefit from advanced stroke therapies, including recombinant tissue plasminogen activator (tPA) and mechanical thrombectomy. The convergence of emergency medical services, telemedicine, and mobile technology, including transportable computed tomography scanners, has presented a unique opportunity to advance patient stroke care in the prehospital field by shortening time to hyperacute stroke treatment with a mobile stroke unit (MSU).

Summary

In this review, we provide a look at the evolution of the MSU into its current status as well as future directions. Our summary statement includes historical and implementation information, economic cost, and published clinical outcome and time metrics, including the utilization rate of thrombolysis.

Key Messages

Initially hypothesized in 2003, the first MSUs were launched in Germany and adopted worldwide in acute, prehospital stroke management. These specialized ambulances have made the diagnosis and treatment of many neurological emergencies, in addition to ischemic and hemorrhagic stroke, possible at the emergency site. Providing treatment as early as possible, including within the prehospital phase of stroke management, improves patient outcomes. As MSUs continue to collect data and improve their methods, shortened time metrics are expected, resulting in more patients who will benefit from faster treatment of their acute neurological emergencies in the prehospital field.

Clinical Information Systems Integration in New York City's First Mobile Stroke Unit

BACKGROUND

Mobile stroke units (MSUs) reduce time to thrombolytic therapy in acute ischemic stroke. These units are widely used, but the clinical information systems underlying MSU operations are understudied.

OBJECTIVE

The first MSU on the East Coast of the United States was established at New York Presbyterian Hospital (NYP) in October 2016. We describe our program's 7-month pilot, focusing on the integration of our hospital's clinical information systems into our MSU to support patient care and research efforts.

METHODS

NYP's MSU was staffed by two paramedics, one radiology technologist, and a vascular neurologist. The unit was equipped with four laptop computers and networking infrastructure enabling all staff to access the hospital intranet and clinical applications during operating hours. A telephone-based registration procedure registered patients from the field into our admit/discharge/transfer system, which interfaced with the institutional electronic health record (EHR). We developed and implemented a computerized physician order entry set in our EHR with prefilled values to permit quick ordering of medications, imaging, and laboratory testing. We also developed and implemented a structured clinician note to facilitate care documentation and clinical data extraction.

RESULTS

Our MSU began operating on October 3, 2016. As of April 27, 2017, the MSU transported 49 patients, of whom 16 received tissue plasminogen activator (t-PA). Zero technical problems impacting patient care were reported around registration, order entry, or intranet access. Two onboard network failures occurred, resulting in computed tomography scanner malfunctions, although no patients became ineligible for time-sensitive treatment as a result. Thirteen (26.5%) clinical notes contained at least one incomplete time field.

CONCLUSION

The main technical challenges encountered during the integration of our hospital's clinical information systems into our MSU were onboard network failures and incomplete clinical documentation. Future studies are necessary to determine whether such integrative efforts improve MSU care quality, and which enhancements to information systems will optimize clinical care and research efforts.

European Academy of Neurology and European Stroke Organization consensus statement and practical guidance for pre-hospital management of stroke

BACKGROUND AND PURPOSE

The reduction of delay between onset and hospital arrival and adequate pre-hospital care of persons with acute stroke are important for improving the chances of a favourable outcome. The objective is to recommend evidence-based practices for the management of patients with suspected stroke in the pre-hospital setting.

METHODS

The GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology was used to define the key clinical questions. An expert panel then reviewed the literature, established the quality of the evidence, and made recommendations.

RESULTS

Despite very low quality of evidence educational campaigns to increase the awareness of immediately calling emergency medical services are strongly recommended. Moderate quality evidence was found to support strong recommendations for the training of emergency medical personnel in recognizing the symptoms of a stroke and in implementation of a pre-hospital 'code stroke' including highest priority dispatch, pre-hospital notification and rapid transfer to the closest 'stroke-ready' centre. Insufficient evidence was found to recommend a pre-hospital stroke scale to predict large vessel occlusion. Despite the very low quality of evidence, restoring normoxia in patients with hypoxia is recommended, and blood pressure lowering drugs and treating hyperglycaemia with insulin should be avoided. There is insufficient evidence to recommend the routine use of mobile stroke units delivering intravenous thrombolysis at the scene. Because only feasibility studies have been reported, no recommendations can be provided for pre-hospital telemedicine during ambulance transport.

CONCLUSIONS

These guidelines inform on the contemporary approach to patients with suspected stroke in the pre-hospital setting. Further studies, preferably randomized controlled trials, are required to examine the impact of particular interventions on quality parameters and outcome.

Thrombolysis in stroke patients: Comparability of point-of-care versus central laboratory international normalized ratio

BACKGROUND

In acute stroke patients, thrombolysis is one gold standard therapy option within the first four hours after the ischemic event. A contraindication for thrombolysis is an International Normalized Ratio (INR) value >1.7. Since time is brain, rapid and reliable INR results are fundamental. Aim was to compare INR values determined by central laboratory (CL) analyzer and Point-of-Care Testing(POCT)-device and to evaluate the quality of POCT performance in cases of potential therapeutic thrombolysis at a certified stroke unit.

METHODS

In 153 patients INR measurements using POCT-devices (HEMOCHRON Signature Elite®) were compared to INR measurements (BCS®XP) performed at the central laboratory. Outlier evaluation was performed regarding the critical thrombolysis cut-off.

RESULTS

Overall, we demonstrated a significant correlation (r = 0.809, p<0.0001) between both measurement methods. Mean value of the absolute difference between CL-INR and POCT-INR measurements was 0.23. In 95.4% of these cases, no differences regarding the critical cut-off (INR 1.7) were observed. POCT-INR values tended to be higher than the CL-INR values (p = 0.01). In 4.6% cases, a different value regarding thrombolysis cut-off was found. All patients were >75 years.

CONCLUSIONS

POCT-INR measurements based on our POCT concept are suitable to determine INR values in critical stroke patients. Nevertheless, outlier evaluation is mandatory.

Administration of tissue plasminogen activator without coagulation results in a Chinese population

Routine coagulation test before intravenous tissue plasminogen activator (tPA) use increases the door to needle time (DNT). We sought to evaluate the safety of tPA use without coagulation results and its impact on prognosis. In our stroke registry, tPA was delivered with coagulation results from December 2015 to April 2016 and without coagulation results from May 2016 to December 2016. Differences of demographics, clinical characteristic, and prognosis between these two groups were analyzed. In addition, logistic regression analysis was conducted to identify predictors for DNT of over 60 min. A total of 201 stroke patients were included in the final analysis. Of these, 81 patients received tPA with coagulation results and 120 patients without coagulation results. Only one (0.8%) patient with abnormal coagulation results met the exclusion criteria of tPA use in patients without coagulation results. The difference of DNT between groups with (mean, 61.7 min) and without (mean, 41.9 min) coagulation results was significant (P = 0.00). The group without coagulation results had a higher rate of favorable 90-day outcome (74.2 vs 70.4%) and lower rates of symptomatic intracranial hemorrhage/nonintracranial hemorrhage (4.9 and 22.2% vs 1.7 and 19.2%) than the group with coagulation results did; these differences were not statistically significant. In multivariate analysis, only tPA use with coagulation results was the predictor for DNT of over 60 min (P = 0.0030, OR = 2.44, 95% CI 1.28-4.65). The present study suggests that tPA could be delivered safely without coagulation results in patients without suspected coagulopathy, and avoiding coagulation tests reduces significantly the DNT interval.

Air Ambulance Delivery and Administration of Four-factor Prothrombin Complex Concentrate Is Feasible and Decreases Time to Anticoagulation Reversal

OBJECTIVES

The objective was to evaluate the feasibility, safety, and preliminary efficacy of four-factor prothrombin complex concentrate (4-factor PCC) administration by an air ambulance service prior to or during transfer of patients with warfarin-associated major hemorrhage to a tertiary care center for definitive management (interventional arm) compared to patients receiving 4-factor PCC following transfer by air ambulance or ground without 4-factor PCC treatment (conventional arm).

METHODS

This was a retrospective chart review of patients presenting to a large academic medical center. All patients presenting to the emergency department (ED) treated with 4-factor PCC from April 1, 2014, through June 30, 2016, were identified. For this study, only transfer patients with an International Normalized Ratio (INR) > 1.5 actively treated with warfarin were included. The primary outcome was the proportion of patients with an INR ≤ 1.5 upon tertiary care hospital arrival, and the secondary efficacy outcome was difference in time to achievement of INR ≤ 1.5. Additional safety and efficacy objectives included difference in thromboembolic complications, length of stay, intensive care unit length of stay, and inpatient mortality between groups.

RESULTS

Of the 72 included patients, a higher proportion of patients in the interventional group had an INR ≤ 1.5 on ED arrival (proportion difference = 0.82, 95% confidence interval = 0.64-0.92, p < 0.0001) and significantly reduced time to observed INR ≤ 1.5 (181 minutes vs. 541 minutes, p = 0.001). No differences were observed in thromboembolic complications or patient-centered outcomes with the exception of mortality, which was significantly higher in patients in the interventional group. This group was also observed to have lower Glasgow Coma Scale score and higher intubation rates prior to transfer and treatment.

CONCLUSIONS

Dispatch of an air ambulance carrying 4-factor PCC with administration prior to transfer is feasible and leads to more rapid improvement in INR among patients with warfarin-associated major hemorrhage.

Stroke identification by criteria based dispatch - a register based study

BACKGROUND

Rapid and precise dispatch of resources is a key element in pre-hospital emergency medicine. Emergency medical communication centres (EMCCs) dispatch resources based on protocols and guidelines, balancing the acute need of the individual and the resource allocation of the pre-hospital emergency medical system. The aim of this study was to determine the validity of stroke identification by the Norwegian dispatch guidelines.

METHOD AND MATERIAL

This was a register-based study where patients suspected for stroke were compared to those with the final diagnosis of stroke as an indicator group for the guideline validation. One EMCC and its three associated hospitals participated with 13 months of data. Four subcodes of the stroke dispatch code were defined as suspicious of stroke and further analysed. Factors associated with stroke identification were explored.

RESULTS

The sensitivity for identifying a stroke patient at initial EMCC contact was 57.9% (51.5, 64.1), specificity was 99.1% (98.9, 99.2), positive predictive value was 45.7% (40.1, 51.4) and negative predictive value was 99.4% (99.3, 99.5). The emergency medical access telephone (113) was initial EMCC contact line in only 48% of the cases. Paralyses and admittance to a smaller hospital were associated with increased probability for stroke (OR 2.6, P = 0.001 and OR 2.7, P = 0.01), respectively.

CONCLUSION

The sensitivity for identification of stroke patients by the dispatch guidelines is modest, while the specificity is high. The 113 telephone line was initial EMCC access point for less than half of the stroke patients.

Deep into the Brain: Artificial Intelligence in Stroke Imaging

Artificial intelligence (AI), a computer system aiming to mimic human intelligence, is gaining increasing interest and is being incorporated into many fields, including medicine. Stroke medicine is one such area of application of AI, for improving the accuracy of diagnosis and the quality of patient care. For stroke management, adequate analysis of stroke imaging is crucial. Recently, AI techniques have been applied to decipher the data from stroke imaging and have demonstrated some promising results. In the very near future, such AI techniques may play a pivotal role in determining the therapeutic methods and predicting the prognosis for stroke patients in an individualized manner. In this review, we offer a glimpse at the use of AI in stroke imaging, specifically focusing on its technical principles, clinical application, and future perspectives.

The PRE-hospital Stroke Treatment Organization

Background

The PRE-hospital Stroke Treatment Organization was formed in 2016 as an international consortium of medical practitioners involved in pre-hospital treatment of patients with acute stroke.

Aims

PRE-hospital Stroke Treatment Organization’s mission is to improve stroke outcomes by supporting research and advocacy for pre-hospital stroke treatment in Mobile Stroke Units. PRE-hospital Stroke Treatment Organization will provide a platform to enhance collaborative research across the spectrum of acute stroke management in the pre-hospital setting. PRE-hospital Stroke Treatment Organization will also facilitate the appropriate proliferation and distribution of Mobile Stroke Units by providing a forum for professional communication, resource for public education, and stimulus for government, industry, and philanthropic support.

Summary of review

In this “white paper”, we describe the evidence supporting pre-hospital stroke treatment, progress to date, practical issues such as application in various environments and staffing, planned research initiatives, and organizational structure.

Conclusions

PRE-hospital Stroke Treatment Organization is not-for-profit, with membership open to anyone involved (or hoping to become involved) in pre-hospital stroke care. PRE-hospital Stroke Treatment Organization has a Steering Committee comprised of members from Europe, U.S., Canada, Australia, and other regions having a Mobile Stroke Unit in operation. PRE-hospital Stroke Treatment Organization convenes satellite meetings for membership at the International Stroke Conference and European Stroke Congress each year to address the PRE-hospital Stroke Treatment Organization mission. The first research collaborations agreed upon are to: (1) develop a list of common data elements to be collected by all Mobile Stroke Unit programs and entered into a common research database, and (2) develop a protocol for investigating the natural history of hyper-acute Intracerebral Hemorrhage.

[Appropriate treatment of acute stroke at all times and in all places : Organizational concepts and new approaches]

Stroke is one of the most common neurological diseases in acute care. The introduction of new organizational concepts in the rescue chain and in acute inpatient services can significantly reduce time to treatment and patients can receive specific therapeutic options that have been shown to improve acute stroke prognosis. This review provides an overview of organizational structures that lead to improved medical care and outlines the evidence-based therapeutic options. This is intended to give the reader a decision support on provision of specific treatment in acute ischemic stroke. The almost simultaneous proof of effectiveness of mechanical thrombectomy for targeted patient populations in five randomized trials has challenged the organization of stroke care. This provides a good example of how an optimized interplay within the rescue chain from emergency services via community hospitals to referral centers with intervention facilities can ensure access to this novel treatment for as many patients as possible. For the limited time span between onset of symptoms and start of treatment, creative but nevertheless well-standardized concepts have emerged that lead to measurable therapeutic success. It has become an urgent challenge to create sustainable regional infrastructures that allow access to appropriate treatment for all patients.

Point-of-Care-Testing in Acute Stroke Management: An Unmet Need Ripe for Technological Harvest

Stroke, the second highest leading cause of death, is caused by an abrupt interruption of blood to the brain. Supply of blood needs to be promptly restored to salvage brain tissues from irreversible neuronal death. Existing assessment of stroke patients is based largely on detailed clinical evaluation that is complemented by neuroimaging methods. However, emerging data point to the potential use of blood-derived biomarkers in aiding clinical decision-making especially in the diagnosis of ischemic stroke, triaging patients for acute reperfusion therapies, and in informing stroke mechanisms and prognosis. The demand for newer techniques to deliver individualized information on-site for incorporation into a time-sensitive work-flow has become greater. In this review, we examine the roles of a portable and easy to use point-of-care-test (POCT) in shortening the time-to-treatment, classifying stroke subtypes and improving patient's outcome. We first examine the conventional stroke management workflow, then highlight situations where a bedside biomarker assessment might aid clinical decision-making. A novel stroke POCT approach is presented, which combines the use of quantitative and multiplex POCT platforms for the detection of specific stroke biomarkers, as well as data-mining tools to drive analytical processes. Further work is needed in the development of POCTs to fulfill an unmet need in acute stroke management.

Pre-hospital ct diagnosis of subarachnoid hemorrhage

Background

Subarachnoid hemorrhage (SAH) is associated with higher mortality in the acute phase than other stroke types. There is a particular risk of early and devastating re-bleeding. Patients therefore need urgent assessment in a neurosurgical department, and the shorter the time from symptom onset to diagnosis the better.

Case presentation

The Norwegian Acute Stroke Pre-hospital Project (NASPP) has developed a Mobile Stroke Unit (MSU) model, which is staffed with anesthesiologists also trained in pre-hospital clinical assessment of acute stroke patients and interpretation of computerized tomography (CT). The MSU was operated on-call from the local dispatch center in a rural area 45–160 km away from a neurosurgical department. Two patients presented with clinical symptoms and signs compatible with SAH. In both cases, the CT examination confirmed the diagnosis of SAH. Both were transported directly from patient location to the regional neurosurgical department, saving at least 2–2.5 h of pre-neurosurgical time.

Conclusion

The Norwegian MSU model staffed with anesthesiologists can rapidly establish an exact diagnosis of SAH, which in a rural area significantly reduces time to neurosurgical care.

Trial registration

Study data are retrospectively registered in ClinicalTrail.gov. NCT03036020

Unique Protocol ID: NASPP-2

Brief Title: The Norwegian Acute Stroke Prehospital Project

Overall Status: Completed

Primary Completion Date: January 2016 [Actual]

Verification Date: January 2017

Mobile stroke units for prehospital thrombolysis, triage, and beyond: benefits and challenges

In acute stroke management, time is brain. Bringing swift treatment to the patient, instead of the conventional approach of awaiting the patient's arrival at the hospital for treatment, is a potential strategy to improve clinical outcomes after stroke. This strategy is based on the use of an ambulance (mobile stroke unit) equipped with an imaging system, a point-of-care laboratory, a telemedicine connection to the hospital, and appropriate medication. Studies of prehospital stroke treatment consistently report a reduction in delays before thrombolysis and cause-based triage in regard to the appropriate target hospital (eg, primary vs comprehensive stroke centre). Moreover, novel medical options for the treatment of stroke patients are also under investigation, such as prehospital differential blood pressure management, reversal of warfarin effects in haemorrhagic stroke, and management of cerebral emergencies other than stroke. However, crucial concerns regarding safety, clinical efficacy, best setting, and cost-effectiveness remain to be addressed in further studies. In the future, mobile stroke units might allow the investigation of novel diagnostic (eg, biomarkers and automated imaging evaluation) and therapeutic (eg, neuroprotective drugs and treatments for haemorrhagic stroke) options in the prehospital setting, thus functioning as a tool for research on prehospital stroke management.

Management of intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a potentially devastating neurologic injury representing 10-15% of stroke cases in the USA each year. Numerous risk factors, including age, hypertension, male gender, coagulopathy, genetic susceptibility, and ethnic descent, have been identified. Timely identification, workup, and management of this condition remain a challenge for clinicians as numerous factors can present obstacles to achieving good functional outcomes. Several large clinical trials have been conducted over the prior decade regarding medical and surgical interventions. However, no specific treatment has shown a major impact on clinical outcome. Current management guidelines do exist based on medical evidence and consensus and these provide a framework for care. While management of hypertension and coagulopathy are generally considered basic tenets of ICH management, a variety of measures for surgical hematoma evacuation, intracranial pressure control, and intraventricular hemorrhage can be further pursued in the emergent setting for selected patients. The complexity of management in parenchymal cerebral hemorrhage remains challenging and offers many areas for further investigation. A systematic approach to the background, pathology, and early management of spontaneous parenchymal hemorrhage is provided.

Implementation of an institution-wide acute stroke algorithm: Improving stroke quality metrics

Background:

In May 2012, an updated stroke algorithm was implemented at Vanderbilt University Medical Center. The current study objectives were to: (1) describe the process of implementing a new stroke algorithm and (2) compare pre- and post-algorithm quality improvement (QI) metrics, specificaly door to computed tomography time (DTCT), door to neurology time (DTN), and door to tPA administration time (DTT).

Methods:

Our institutional stroke algorithm underwent extensive revision, with a focus on removing variability, streamlining care, and improving time delays. The updated stroke algorithm was implemented in May 2012. Three primary stroke QI metrics were evaluated over four separate 3-month time points, one pre- and three post-algorithm periods.

Results:

The following data points improved after algorithm implementation: average DTCT decreased from 39.9 to 12.8 min (P < 0.001); average DTN decreased from 34.1 to 8.2 min (P ≤ 0.001), and average DTT decreased from 62.5 to 43.5 min (P = 0.17).

Conclusion:

A new stroke protocol that prioritized neurointervention at our institution resulted in significant lowering in the DTCT and DTN, with a nonsignificant improvement in DTT.