Effect of an Enhanced Paramedic Acute Stroke Treatment Assessment on Thrombolysis Delivery During Emergency Stroke Care: A Cluster Randomized Clinical Trial

A Multi-Parametric Approach for Characterising Cerebral Haemodynamics in Acute Ischaemic and Haemorrhagic Stroke

BACKGROUND AND PURPOSE

Early differentiation between acute ischaemic (AIS) and haemorrhagic stroke (ICH), based on cerebral and peripheral hemodynamic parameters, would be advantageous to allow for pre-hospital interventions. In this preliminary study, we explored the potential of multiple parameters, including dynamic cerebral autoregulation, for phenotyping and differentiating each stroke sub-type.

METHODS

Eighty patients were included with clinical stroke syndromes confirmed by computed tomography within 48 h of symptom onset. Continuous recordings of bilateral cerebral blood velocity (transcranial Doppler ultrasound), end-tidal CO2 (capnography), electrocardiogram (ECG), and arterial blood pressure (ABP, Finometer) were used to derive 67 cerebral and peripheral parameters.

RESULTS

A total of 68 patients with AIS (mean age 66.8 ± SD 12.4 years) and 12 patients with ICH (67.8 ± 16.2 years) were included. The median ± SD NIHSS of the cohort was 5 ± 4.6. Statistically significant differences between AIS and ICH were observed for (i) an autoregulation index (ARI) that was higher in the unaffected hemisphere (UH) for ICH compared to AIS (5.9 ± 1.7 vs. 4.9 ± 1.8 p = 0.07); (ii) coherence function for both hemispheres in different frequency bands (AH, p < 0.01; UH p < 0.02); (iii) a baroreceptor sensitivity (BRS) for the low-frequency (LF) bands that was higher for AIS (6.7 ± 4.2 vs. 4.10 ± 2.13 ms/mmHg, p = 0.04) compared to ICH, and that the mean gain of the BRS in the LF range was higher in the AIS than in the ICH (5.8 ± 5.3 vs. 2.7 ± 1.8 ms/mmHg, p = 0.0005); (iv) Systolic and diastolic velocities of the affected hemisphere (AH) that were significantly higher in ICH than in AIS (82.5 ± 28.09 vs. 61.9 ± 18.9 cm/s), systolic velocity (p = 0.002), and diastolic velocity (p = 0.05).

CONCLUSION

Further multivariate modelling might improve the ability of multiple parameters to discriminate between AIS and ICH and warrants future prospective studies of ultra-early classification (<4 h post symptom onset) of stroke sub-types.

Physiological Variability during Prehospital Stroke Care: Which Monitoring and Interventions Are Used?

Prehospital care is a fundamental component of stroke care that predominantly focuses on shortening the time between diagnosis and reaching definitive stroke management. With growing evidence of the physiological parameters affecting long-term patient outcomes, prehospital clinicians need to consider the balance between rapid transfer and increased physiological-parameter monitoring and intervention. This systematic review explores the existing literature on prehospital physiological monitoring and intervention to modify these parameters in stroke patients. The systematic review was registered on PROSPERO (CRD42022308991) and conducted across four databases with citation cascading. Based on the identified inclusion and exclusion criteria, 19 studies were retained for this review. The studies were classified into two themes: physiological-monitoring intervention and pharmacological-therapy intervention. A total of 14 included studies explored prehospital physiological monitoring. Elevated blood pressure was associated with increased hematoma volume in intracerebral hemorrhage and, in some reports, with increased rates of early neurological deterioration and prehospital neurological deterioration. A reduction in prehospital heart rate variability was associated with unfavorable clinical outcomes. Further, five of the included records investigated the delivery of pharmacological therapy in the prehospital environment for patients presenting with acute stroke. BP-lowering interventions were successfully demonstrated through three trials; however, evidence of their benefit to clinical outcomes is limited. Two studies investigating the use of oxygen and magnesium sulfate as neuroprotective agents did not demonstrate an improvement in patient's outcomes. This systematic review highlights the absence of continuous physiological parameter monitoring, investigates fundamental physiological parameters, and provides recommendations for future work, with the aim of improving stroke patient outcomes.

Canadian Stroke Best Practice Recommendations: Acute Stroke Management, 7th Edition Practice Guidelines Update, 2022

The 2022 update of the Canadian Stroke Best Practice Recommendations (CSBPR) for Acute Stroke Management, 7th edition, is a comprehensive summary of current evidence-based recommendations, appropriate for use by an interdisciplinary team of healthcare providers and system planners caring for persons with an acute stroke or transient ischemic attack. These recommendations are a timely opportunity to reassess current processes to ensure efficient access to acute stroke diagnostics, treatments, and management strategies, proven to reduce mortality and morbidity. The topics covered include prehospital care, emergency department care, intravenous thrombolysis and endovascular thrombectomy (EVT), prevention and management of inhospital complications, vascular risk factor reduction, early rehabilitation, and end-of-life care. These recommendations pertain primarily to an acute ischemic vascular event. Notable changes in the 7th edition include recommendations pertaining the use of tenecteplase, thrombolysis as a bridging therapy prior to mechanical thrombectomy, dual antiplatelet therapy for stroke prevention, the management of symptomatic intracerebral hemorrhage following thrombolysis, acute stroke imaging, care of patients undergoing EVT, medical assistance in dying, and virtual stroke care. An explicit effort was made to address sex and gender differences wherever possible. The theme of the 7th edition of the CSBPR is building connections to optimize individual outcomes, recognizing that many people who present with acute stroke often also have multiple comorbid conditions, are medically more complex, and require a coordinated interdisciplinary approach for optimal recovery. Additional materials to support timely implementation and quality monitoring of these recommendations are available at www.strokebestpractices.ca.

A systematic review of ambulance service-based randomised controlled trials in stroke

BACKGROUND

Treatment for stroke is time-dependent, and ambulance services play a vital role in the early recognition, assessment and transportation of stroke patients. Innovations which begin in ambulance services to expedite delivery of treatments for stroke are developing. However, research delivery in ambulance services is novel, developing and not fully understood.

AIMS

To synthesise literature encompassing ambulance service-based randomised controlled interventions for acute stroke with consideration to the characteristics of the type of intervention, consent modality, time intervals and issues unique to research delivery in ambulance services. Online searches of MEDLINE, EMBASE, Web of Science, CENTRAL and WHO IRCTP databases and hand searches identified 15 eligible studies from 538. Articles were heterogeneous in nature and meta-analysis was partially available as 13 studies reported key time intervals, but terminology varied. Randomised interventions were evident across all points of contact with ambulance services: identification of stroke during the call for help, higher dispatch priority assigned to stroke, on-scene assessment and clinical interventions, direct referral to comprehensive stroke centres and definitive care delivery at scene. Consent methods ranged between informed patient, waiver and proxy modalities with country-specific variation. Challenges unique to the prehospital setting comprise the geographical distribution of ambulance resources, low recruitment rates, prolonged recruitment phases, management of investigational medicinal product and incomplete datasets.

CONCLUSION

Research opportunities exist across all points of contact between stroke patients and ambulance services, but randomisation and consent remain novel. Early collaboration and engagement between trialists and ambulance services will alleviate some of the complexities reported.

REGISTRATION NUMBER

PROSPERO 2018CRD42018075803.

Challenges and Experiences in Multicenter Prehospital Stroke Research: Narrative Data from the Rapid Intervention with Glyceryl Trinitrate in Hypertensive Stroke Trial-2 (RIGHT-2)

BACKGROUND

Ambulance services are increasingly research active and the Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial-2 (RIGHT-2) is the largest United Kingdom (UK) ambulance-based randomized controlled trial in stroke. We explore the complexities and challenges encountered during RIGHT-2.

METHODS

Five hundred and sixteen of 1487 paramedics from eight UK ambulance services serving 54 comprehensive or primary stroke care centers screened and consented 1149 patients presenting within 4 h of FAST-positive stroke and with systolic blood pressure >120 mmHg; participants were randomized to treatment with transdermal glyceryl trinitrate versus sham patch in the ambulance.

KEY FINDINGS

Working with multiple ambulance services demanded flexibility in the trial protocol to overcome variation in operating procedures to ensure deliverability. Many paramedics are novice researchers, and research concepts and practices are emerging including consent strategies in emergency stroke care. Regional variation in hospital participation and hours/days of operation presented paramedics with additional considerations prior to patient recruitment. The working hours of hospital research staff often do not reflect the 24/7 nature of ambulance work, which challenged deliverability until trial processes became fully embedded. Management of investigational medicinal product between ambulance stations, in-transit when on ambulance vehicles and on handover at hospital, necessitated an in-depth review to maintain accountability.

CONCLUSION

RIGHT-2 demonstrated that although there are significant practical challenges to conducting multicenter ambulance-based research in a time-dependent environment, careful planning and management facilitated delivery. Lessons learned here will help inform the design and conduct of future ambulance-based trials.

Prehospital screening of acute stroke with the National Institutes of Health Stroke Scale (ParaNASPP): a stepped-wedge, cluster-randomised controlled trial

BACKGROUND

Timely treatment of acute stroke depends on early identification and triage. Improved methods for recognition of stroke in the prehospital setting are needed. We aimed to assess whether use of the National Institutes of Health Stroke Scale (NIHSS) by paramedics in the ambulance could improve communication with the hospital, augment triage, and enhance diagnostic accuracy of acute stroke.

METHODS

The Paramedic Norwegian Acute Stroke Prehospital Project (ParaNASPP) was a stepped-wedge, single-blind, cluster-randomised controlled trial. Patients with suspected acute stroke, who were evaluated by paramedics from five ambulance stations in Oslo, Norway, were eligible for inclusion. The five ambulance stations (defined as clusters) all initially managed patients according to a standard stroke protocol (control group), with randomised sequential crossover of each station to the intervention group. The intervention consisted of supervised training on NIHSS scoring, a mobile application to aid scoring, and standardised communication with stroke physicians. Random allocation was done via a simple lottery draw by administrators at Oslo University Hospital, who were independent of the research team. Allocation concealment was not possible due to the nature of the intervention. The primary outcome was the positive predictive value (PPV) for prehospital identification of patients with a final discharge diagnosis of acute stroke, analysed by intention to treat. Prespecified secondary safety outcomes were median prehospital on-scene time and median door-to-needle time. This trial is registered with ClinicalTrials.gov, NCT04137874, and is completed.

FINDINGS

Between June 3, 2019, and July 1, 2021, 935 patients were evaluated by paramedics for suspected acute stroke. 134 patients met exclusion criteria or did not consent to participate. The primary analysis included 447 patients in the intervention group and 354 in the control group. There was no difference in PPV for prehospital identification of patients with a final discharge diagnosis of acute stroke between the intervention group (48·1%, 95% CI 43·4-52·8) and control group (45·8%, 40·5-51·1), with an estimated percentage points difference between groups of 2·3 (95% CI -4·6 to 9·3; p=0·51). Median prehospital on-scene time increased by 5 min in the intervention group (29 min [IQR 23-36] vs 24 min [19-31]; p<0·0001), whereas median door-to-needle time was similar between groups (26 min [21-36] vs 27 min [20-36]; p=0·90). No prehospital deaths were reported in either group.

INTERPRETATION

The intervention did not improve diagnostic accuracy in patients with suspected stroke. A general increase in prehospital time during the pandemic and the identification of smaller strokes that require more deliberation are possible explanations for the increased on-scene time. The ParaNASPP model is to be implemented in Norway from 2023, and will provide real-life data for further research.

FUNDING

Norwegian Air Ambulance Foundation and Oslo University Hospital.

What factors contribute towards ambulance on-scene times for suspected stroke patients? An observational study

INTRODUCTION

Pre-hospital stroke care focusses on rapid access to specialist stroke units, but UK ambulance data shows increasing pre-hospital times. This study aimed to describe factors contributing towards ambulance on-scene times (OST) for suspected stroke patients and identify targets for a future intervention.

PATIENTS AND METHODS

Ambulance clinicians in North East Ambulance Service were asked to complete a survey after transporting any suspected stroke patients to describe the patient encounter, interventions and timings. Completed surveys were linked with electronic patient care records. Potentially modifiable factors were identified by the study team. Poisson regression analysis quantified the association of selected potentially modifiable factors with OST.

RESULTS

About 2037 suspected stroke patients were conveyed between July and December 2021, resulting in 581 fully completed surveys by 359 different clinicians. The median age of patients was 75 years (interquartile range (IQR) 66-83) and 52% of patients were male. Median OST was 33 min (IQR 26-41). Three potentially modifiable factors were identified as contributors to extended OST. Performing additional advanced neurological assessments added 10% to OST (34 vs 31 min, p = 0.008); intravenous cannulation added 13% (35 vs 31 min, p = <0.001) and ECGs added 22% (35 vs 28 min, p = <0.001).

CONCLUSIONS

This study identified three potentially modifiable factors that increased pre-hospital OST with suspected stroke patients. This type of data can be used to target interventions at behaviours that extend pre-hospital OST but which have questionable patient benefit. This approach will be evaluated in a follow up study in the North East of England.

The RESearch PARamedic Experience (RESPARE) study: a qualitative study exploring the experiences of research paramedics working in the United Kingdom

Background

The research paramedic position is a relatively niche role undertaken by a small number of paramedics who support, deliver and promote research. Research paramedic roles provide opportunities to develop talented researchers who are recognised as vital elements of developing a research culture within ambulance services. The benefits of research-active clinicians have been recognised at a national level. The aim of this study was to explore the experience of people who work, or have worked, as research paramedics.

Methods

A generic qualitative approach underpinned by phenomenological concepts was used. Volunteers were recruited via ambulance research leads and social media. Online focus groups allowed participants to discuss their roles with peers who may be geographically distant. Semi-structured interviews expanded on the focus group findings. Data were recorded, transcribed verbatim and analysed using framework analysis.

Results

Eighteen paramedics (66% female, median involvement in research six (interquartile range 2-7) years) representing eight English NHS ambulance trusts participated in three focus groups and five interviews lasting around one hour, in November and December 2021.Six key themes were identified: starting as a research paramedic; barriers and facilitators to working as a research paramedic; research careers; opportunities; the community (support and networking); and the value of a clinical identity.

Conclusions

Many research paramedics had similar experiences in terms of starting their career by delivering research for large studies, then building on this experience and the networks they create to develop their own research. There are common organisational and financial barriers to working as a research paramedic. Career progression in research beyond the research paramedic role is not well defined, but often involves building links outside of the ambulance service.

Simulation-based team training improves door-to-needle time for intravenous thrombolysis

PURPOSE

There is a clinical need for shortened door-to-needle time (DNT) for intravenous thrombolysis, but effective training methods are missing. Simulation training improves teamwork and logistics in numerous fields. Still, it is not clear if simulation improves logistics in stroke.

METHODS

To evaluate the efficiency of a simulation training programme, the DNT of participating centres was compared with the rest of stroke centres in the Czech Republic. Patients' data were prospectively collected from the nationally used Safe Implementation of Treatments in Stroke Registry. The outcome was an improvement in DNT in 2018 as compared with 2015 (after and before the simulation training). Scenarios were based on real clinical cases, and simulation courses were conducted in a standardly equipped simulation centre.

FINDINGS

Between 2016 and 2017, 10 courses were conducted for stroke teams from 9 of all 45 stroke centres. DNT data were available both in 2015 and 2018 from 41 (91%) stroke centres. The simulation training improved the DNT in 2018 as compared with 2015 by 30 min (95% CI 25.7 to 34.7) and as compared with 20 min (95% CI 15.8 to 24.3) in stroke centres without the simulation training (p=0.01). Any parenchymal haemorrhage occurred in 5.4% and 3.5% of patients treated in centres without and with simulation training (p=0.054), respectively.

CONCLUSIONS

DNT was considerably shortened nationally. It was feasible to implement simulation as a nationwide training programme. The simulation was associated with improved DNT; however, other studies should confirm that such an association is causal.

Transcranial Doppler analysis based on computer and artificial intelligence for acute cerebrovascular disease

Cerebrovascular disease refers to damage to brain tissue caused by impaired intracranial blood circulation. It usually presents clinically as an acute nonfatal event and is characterized by high morbidity, disability, and mortality. Transcranial Doppler (TCD) ultrasonography is a non-invasive method for the diagnosis of cerebrovascular disease that uses the Doppler effect to detect the hemodynamic and physiological parameters of the major intracranial basilar arteries. It can provide important hemodynamic information that cannot be measured by other diagnostic imaging techniques for cerebrovascular disease. And the result parameters of TCD ultrasonography such as blood flow velocity and beat index can reflect the type of cerebrovascular disease and serve as a basis to assist physicians in the treatment of cerebrovascular diseases. Artificial intelligence (AI) is a branch of computer science which is used in a wide range of applications in agriculture, communications, medicine, finance, and other fields. In recent years, there are much research devoted to the application of AI to TCD. The review and summary of related technologies is an important work to promote the development of this field, which can provide an intuitive technical summary for future researchers. In this paper, we first review the development, principles, and applications of TCD ultrasonography and other related knowledge, and briefly introduce the development of AI in the field of medicine and emergency medicine. Finally, we summarize in detail the applications and advantages of AI technology in TCD ultrasonography including the establishment of an examination system combining brain computer interface (BCI) and TCD ultrasonography, the classification and noise cancellation of TCD ultrasonography signals using AI algorithms, and the use of intelligent robots to assist physicians in TCD ultrasonography and discuss the prospects for the development of AI in TCD ultrasonography.

Time intervals and distances travelled for prehospital ambulance stroke care: data from the randomised-controlled ambulance-based Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial-2 (RIGHT-2)

OBJECTIVES

Ambulances offer the first opportunity to evaluate hyperacute stroke treatments. In this study, we investigated the conduct of a hyperacute stroke study in the ambulance-based setting with a particular focus on timings and logistics of trial delivery.

DESIGN

Multicentre prospective, single-blind, parallel group randomised controlled trial.

SETTING

Eight National Health Service ambulance services in England and Wales; 54 acute stroke centres.

PARTICIPANTS

Paramedics enrolled 1149 patients assessed as likely to have a stroke, with Face, Arm, Speech and Time score (2 or 3), within 4 hours of symptom onset and systolic blood pressure >120 mm Hg.

INTERVENTIONS

Paramedics administered randomly assigned active transdermal glyceryl trinitrate or sham.

PRIMARY AND SECONDARY OUTCOMES

Modified Rankin scale at day 90. This paper focuses on response time intervals, distances travelled and baseline characteristics of patients, compared between ambulance services.

RESULTS

Paramedics enrolled 1149 patients between September 2015 and May 2018.

FINAL DIAGNOSIS

intracerebral haemorrhage 13%, ischaemic stroke 52%, transient ischaemic attack 9% and mimic 26%. Timings (min) were (median (25-75 centile)): onset to emergency call 19 (5-64); onset to randomisation 71 (45-116); total time at scene 33 (26-46); depart scene to hospital 15 (10-23); randomisation to hospital 24 (16-34) and onset to hospital 97 (71-141). Ambulances travelled (km) 10 (4-19) from scene to hospital. Timings and distances differed between ambulance service, for example, onset to randomisation (fastest 53 min, slowest 77 min; p<0.001), distance from scene to hospital (least 4 km, most 20 km; p<0.001).

CONCLUSION

We completed a large prehospital stroke trial involving a simple-to-administer intervention across multiple ambulance services. The time from onset to randomisation and modest distances travelled support the applicability of future large-scale paramedic-delivered ambulance-based stroke trials in urban and rural locations.

TRIAL REGISTRATION NUMBER

ISRCTN26986053.

Implementation of the Helsinki Model at West Tallinn Central Hospital

Ischemic stroke is defined as neurological deficit caused by brain infarction. The intravenous tissue plasminogen activator, alteplase, is an effective treatment. However, efficacy of this method is time dependent. An important step in improving outcome and increasing the number of patients receiving alteplase is the shortening of waiting times at the hospital, the so-called door-to-needle time (DNT). The comprehensive Helsinki model was proposed in 2012, which enabled the shortening of the DNT to less than 20 min. Background and Objectives: The aim of this study was to analyze the transferability of the suggested model to the West Tallinn Central Hospital (WTCH). Materials and Methods: Since the first thrombolysis in 2005, all patients are registered in the WTCH thrombolysis registry. Several steps following the Helsinki model have been implemented over the years. Results: The results demonstrate that the number and also the percent of thrombolysed stroke patients increased during the years, from a few thrombolysis annually, to 260 in 2021. The mean DNT dropped significantly to 33 min after the implementation of several steps, from the emergency medical services (EMS) prenotification with a phone call to the neurologists, to the setting-up of a thrombolysis team based in the stroke unit. Also, the immediate start of treatment using a computed tomography table was introduced. Conclusions: In conclusion, several implemented steps enabled the shortening of the DNT from 30 to 25.2 min. Short DNTs were achieved and maintained only with EMS prenotification.

Improving emergency treatment for patients with acute stroke: the PEARS research programme, including the PASTA cluster RCT

Background

Intravenous thrombolysis and intra-arterial thrombectomy are proven emergency treatments for acute ischaemic stroke, but they require rapid delivery to selected patients within specialist services. National audit data have shown that treatment provision is suboptimal.

Objectives

The aims were to (1) determine the content, clinical effectiveness and day 90 cost-effectiveness of an enhanced paramedic assessment designed to facilitate thrombolysis delivery in hospital and (2) model thrombectomy service configuration options with optimal activity and cost-effectiveness informed by expert and public views.

Design

A mixed-methods approach was employed between 2014 and 2019. Systematic reviews examined enhanced paramedic roles and thrombectomy effectiveness. Professional and service user groups developed a thrombolysis-focused Paramedic Acute Stroke Treatment Assessment, which was evaluated in a pragmatic multicentre cluster randomised controlled trial and parallel process evaluation. Clinicians, patients, carers and the public were surveyed regarding thrombectomy service configuration. A decision tree was constructed from published data to estimate thrombectomy eligibility of the UK stroke population. A matching discrete-event simulation predicted patient benefits and financial consequences from increasing the number of centres.

Setting

The paramedic assessment trial was hosted by three regional ambulance services (in north-east England, north-west England and Wales) serving 15 hospitals.

Participants

A total of 103 health-care representatives and 20 public representatives assisted in the development of the paramedic assessment. The trial enrolled 1214 stroke patients within 4 hours of symptom onset. Thrombectomy service provision was informed by a Delphi exercise with 64 stroke specialists and neuroradiologists, and surveys of 147 patients and 105 public respondents.

Interventions

The paramedic assessment comprised additional pre-hospital information collection, structured hospital handover, practical assistance up to 15 minutes post handover, a pre-departure care checklist and clinician feedback.

Main outcome measures

The primary outcome was the proportion of patients receiving thrombolysis. Secondary outcomes included day 90 health (poor status was a modified Rankin Scale score of > 2). Economic outputs reported the number of cases treated and cost-effectiveness using quality-adjusted life-years and Great British pounds.

Data sources

National registry data from the Sentinel Stroke National Audit Programme and the Scottish Stroke Care Audit were used.

Review methods

Systematic searches of electronic bibliographies were used to identify relevant literature. Study inclusion and data extraction processes were described using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

Results

The paramedic assessment trial found a clinically important but statistically non-significant reduction in thrombolysis among intervention patients, compared with standard care patients [197/500 (39.4%) vs. 319/714 (44.7%), respectively] (adjusted odds ratio 0.81, 95% confidence interval 0.61 to 1.08; p = 0.15). The rate of poor health outcomes was not significantly different, but was lower in the intervention group than in the standard care group [313/489 (64.0%) vs. 461/690 (66.8%), respectively] (adjusted odds ratio 0.86, 95% confidence interval 0.60 to 1.2; p = 0.39). There was no difference in the quality-adjusted life-years gained between the groups (0.005, 95% confidence interval –0.004 to 0.015), but total costs were significantly lower for patients in the intervention group than for those in the standard care group (–£1086, 95% confidence interval –£2236 to –£13). It has been estimated that, in the UK, 10,140–11,530 patients per year (i.e. 12% of stroke admissions) are eligible for thrombectomy. Meta-analysis of published data confirmed that thrombectomy-treated patients were significantly more likely to be functionally independent than patients receiving standard care (odds ratio 2.39, 95% confidence interval 1.88 to 3.04; n = 1841). Expert consensus and most public survey respondents favoured selective secondary transfer for accessing thrombectomy at regional neuroscience centres. The discrete-event simulation model suggested that six new English centres might generate 190 quality-adjusted life-years (95% confidence interval –6 to 399 quality-adjusted life-years) and a saving of £1,864,000 per year (95% confidence interval –£1,204,000 to £5,017,000 saving per year). The total mean thrombectomy cost up to 72 hours was £12,440, mostly attributable to the consumables. There was no significant cost difference between direct admission and secondary transfer (mean difference –£368, 95% confidence interval –£1016 to £279; p = 0.26).

Limitations

Evidence for paramedic assessment fidelity was limited and group allocation could not be masked. Thrombectomy surveys represented respondent views only. Simulation models assumed that populations were consistent with published meta-analyses, included limited parameters reflecting underlying data sets and did not consider the capital costs of setting up new services.

Conclusions

Paramedic assessment did not increase the proportion of patients receiving thrombolysis, but outcomes were consistent with improved cost-effectiveness at day 90, possibly reflecting better informed treatment decisions and/or adherence to clinical guidelines. However, the health difference was non-significant, small and short term. Approximately 12% of stroke patients are suitable for thrombectomy and widespread provision is likely to generate health and resource gains. Clinician and public views support secondary transfer to access treatment.

Future work

Further evaluation of emergency care pathways will determine whether or not enhanced paramedic assessment improves hospital guideline compliance. Validation of the simulation model post reconfiguration will improve precision and describe wider resource implications.

Trial registration

This trial is registered as ISRCTN12418919 and the systematic review protocols are registered as PROSPERO CRD42014010785 and PROSPERO CRD42015016649.

Funding

The project was funded by the National Institute for Health and Care Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 10, No. 4. See the NIHR Journals Library website for further project information.

Interactive Training of the Emergency Medical Services Improved Prehospital Stroke Recognition and Transport Time

Background and Purpose

Acute stroke treatment outcomes are predicated on reperfusion timeliness which can be improved by better prehospital stroke identification. We aimed to assess the effect of interactive emergency medical services (EMS) training on stroke recognition and prehospital care performance in a very high-risk cardiovascular risk population in Lithuania.

Methods

We conducted a single-center interrupted time-series study between March 1, 2019 and March 15, 2020. Two-hour small-group interactive stroke training sessions were organized for 166 paramedics serving our stroke network. We evaluated positive predictive value (PPV) and sensitivity for stroke including transient ischemic attack identification, onset-to-door time, and hospital-based outcomes during 6-months prior and 3.5 months after the training. The study outcomes were compared between EMS providers in urban and suburban areas.

Results

In total, 677 suspected stroke cases and 239 stroke chameleons (median age 75 years, 54.8% women) were transported by EMS. After the training, we observed improved PPV for stroke recognition (79.8% vs. 71.8%, p = 0.017) and a trend of decreased in-hospital mortality (7.8% vs. 12.3, p = 0.070). Multivariable logistic regression models adjusted for age, gender, EMS location, and stroke subtype showed an association between EMS stroke training and improved odds of stroke identification (adjusted odds ratio [aOR] 1.6 [1.1–2.3]) and onset-to-door ≤ 90 min (aOR 1.6 [1.1–2.5]). The improvement of PPV was observed in urban EMS (84.9% vs. 71.2%, p = 0.003), but not in the suburban group (75.0% vs. 72.6%, p = 0.621).

Conclusions

The interactive EMS training was associated with a robust improvement of stroke recognition, onset to hospital transport time, and a trend of decreased in-hospital mortality. Adapted training strategies may be needed for EMS providers in suburban areas. Future studies should evaluate the long-term effects of the EMS training and identify optimal retraining intervals.

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.

Do methods of hospital pre-alerts influence the on-scene times for acute pre-hospital stroke patients? A retrospective observational study

INTRODUCTION

Stroke is one of the leading causes of death and disability worldwide. The ambulance service is often the first medical service to reach an acute stroke patient, and due to the time-critical nature of stroke, a time-critical assessment and rapid transport to a hyper acute stroke unit are essential. As stroke services have been centralised, different hospitals have implemented different pre-alert admission policies that may affect the on-scene time of the attending ambulance crew. The aim of this study is to investigate if the different pre-alert admission policies affect time on scene.

METHOD

The current study is a retrospective quantitative observational study using data routinely collected by North East Ambulance Service NHS Foundation Trust. The time on scene was divided into two variables; group one was a telephone pre-alert in which a telephone discussion with the receiving hospital is required before they accept admission of the patient. Group two was a radio-style pre-alert in which the attending clinician makes an autonomous decision on the receiving hospital and alerts them via a short radio message of the incoming patient. These times were then compared to identify if there was any difference between them.

RESULTS

Data on 927 patients over a three-month period, from October to December 2019, who had received the full stroke bundle of care, were within the thrombolysis window and recorded as a stroke by the attending clinician, were split into the variable groups and reported on. The mean time on scene for a telephone call pre-alert was 33 minutes and 19 seconds, with a standard deviation of 13 minutes and 8 seconds. The mean on-scene time for a radio pre-alert was 28 minutes and 24 seconds, with a standard deviation of 11 minutes and 51 seconds.

CONCLUSION

A pre-alert given via radio instead of via telephone is shown to have a mean time saving of 4 minutes and 55 seconds, representing an important decrease in time which could be beneficial to patients.

Effect of prehospital workflow optimization on treatment delays and clinical outcomes in acute ischemic stroke: A systematic review and meta-analysis

BACKGROUND

The prehospital phase is critical in ensuring that stroke treatment is delivered quickly and is a major source of time delay. This study sought to identify and examine prehospital stroke workflow optimizations (PSWOs) and their impact on improving health systems, reperfusion rates, treatment delays, and clinical outcomes.

METHODS

The authors conducted a systematic literature review and meta-analysis by extracting data from several research databases (PubMed, Cochrane, Medline, and Embase) published since 2005. We used appropriate key search terms to identify clinical studies concerning prehospital workflow optimization, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

The authors identified 27 articles that looked at the impact of prehospital workflow optimizations on time and treatment parameters; 26 were included in the meta-analysis. The PSWO were subgrouped into three categories: improved intravenous thrombolysis (IVT) triage, large-vessel occlusion (LVO) bypass, and mobile stroke unit (MSU). The salient findings are as follows: improved IVT triage led to significantly improved rates of IVT (relative risk [RR] = 1.80, 95% confidence interval [CI] = 1.18 to 2.75); however, MSU did not (RR = 1.22, 95% CI = 0.98 to 1.52). Improved IVT triage (standard mean difference [SMD] = -0.82, 95% CI = -1.32 to -0.32), LVO bypass (SMD = -0.80, 95% CI = -1.13 to -0.47), and MSU (SMD = -0.87, 95% CI = -1.57 to -0.17) were found to significantly reduce door-to-needle time for IVT. MSU was found to significantly reduce call-to-needle (SMD = -1.41, 95% CI = -1.94 to -0.88) and onset-to-needle (SMD = -1.15, 95% CI = -1.74 to -0.56) times for IVT. MSU additionally demonstrated significant reduction in door-to-perfusion (SMD = -0.72, 95% CI = -1.32 to -0.12) as well as call-to-perfusion (SMD = -0.73, 95% CI = -1.08 to -0.38) times for EVT. Finally, PSWO did not demonstrate significant improvements in rates of good functional outcome (RR = 1.04, 95% CI = 0.97 to 1.12) or mortality at 90 days (RR = 1.00, 95% CI = 0.76 to 1.31).

CONCLUSIONS

This systematic review and meta-analysis found that PSWO significantly improves several time metrics related to stroke treatment leading to improvement in IVT reperfusion rates. Thus, the implementation of these measures in stroke networks is a promising avenue to improve an often-neglected aspect of the stroke response. However, the limited available data suggest functional outcomes and mortality are not significantly improved by PSWO; hence, further studies and improvement strategies vis-à-vis PSWOs are warranted.

Emergency Care of Patients with Acute Ischemic Stroke

Stroke is a leading cause of morbidity and mortality and a major cause of long-term disability. Management of acute ischemic stroke in the first hours is critical to patient outcomes. This review provides an overview of acute ischemic stroke management, with a focus on the golden hour. Additional topics discussed include prehospital considerations and initial evaluation of the patient with history, examination, and imaging as well as treatment options, including thrombolysis and endovascular therapy.

Cost-effectiveness of an enhanced Paramedic Acute Stroke Treatment Assessment (PASTA) during emergency stroke care: Economic results from a pragmatic cluster randomized trial

Background

The Paramedic Acute Stroke Treatment Assessment (PASTA) trial evaluated an enhanced emergency care pathway which aimed to facilitate thrombolysis in hospital. A pre-planned health economic evaluation was included. The main results showed no statistical evidence of a difference in either thrombolysis volume (primary outcome) or 90-day dependency. However, counter-intuitive findings were observed with the intervention group showing fewer thrombolysis treatments but less dependency.

Aims

Cost-effectiveness of the PASTA intervention was examined relative to standard care.

Methods

A within trial cost-utility analysis estimated mean costs and quality-adjusted life years over 90 days’ time horizon. Costs were derived from resource utilization data for individual trial participants. Quality-adjusted life years were calculated by mapping modified Rankin scale scores to EQ-5D-3L utility tariffs. A post-hoc subgroup analysis examined cost-effectiveness when trial hospitals were divided into compliant and non-compliant with recommendations for a stroke specialist thrombolysis rota.

Results

The trial enrolled 1214 patients: 500 PASTA and 714 standard care. There was no evidence of a quality-adjusted life year difference between groups [0·007 (95% CI: −0·003 to 0·018)] but costs were lower in the PASTA group [−£1473 (95% CI: −£2736 to −£219)]. There was over 97.5% chance that the PASTA pathway would be considered cost-effective. There was no evidence of a difference in costs at seven thrombolysis rota compliant hospitals but costs at eight non-complaint hospitals costs were lower in PASTA with more dominant cost-effectiveness.

Conclusions

Analyses indicate that the PASTA pathway may be considered cost-effective, particularly if deployed in areas where stroke specialist availability is limited.

Trial Registration: ISRCTN12418919 www.isrctn.com/ISRCTN12418919

Paramedic experiences of using an enhanced stroke assessment during a cluster randomised trial: a qualitative thematic analysis

Background

Intravenous thrombolysis is a key element of emergency treatment for acute ischaemic stroke, but hospital service delivery is variable. The Paramedic Acute Stroke Treatment Assessment (PASTA) multicentre cluster randomised controlled trial evaluated whether an enhanced paramedic-initiated stroke assessment pathway could improve thrombolysis volume. This paper reports the findings of a parallel process evaluation which explored intervention paramedics’ experience of delivering the enhanced assessment.

Methods

Interviewees were recruited from 453 trained intervention paramedics across three UK ambulance services hosting the trial: North East, North West and Welsh Ambulance Services. A semistructured interview guide aimed to (1) explore the stroke-specific assessment and handover procedures which were part of the PASTA pathway and (2) enable paramedics to share relevant views about expanding their role and any barriers/enablers they encountered. Interviews were audiorecorded, transcribed verbatim and analysed following the principles of the constant comparative method.

Results

Twenty-six interviews were conducted (11 North East, 10 North West and 5 Wales). Iterative data analysis identified four key themes, which reflected paramedics’ experiences at different stages of the care pathway: (1) Enhanced assessment at scene: paramedics felt this improved their skillset and confidence. (2) Prealert to hospital: a mixed experience dependent on receiving hospital staff. (3) Handover to hospital team: standardisation of format was viewed as the primary benefit of the PASTA pathway. (4) Assisting in hospital and feedback: due to professional boundaries, paramedics found these aspects harder to achieve, although feedback from the clinical team was valued when available.

Conclusion

Paramedics believed that the PASTA pathway enhanced their skills and the emergency care of stroke patients, but a continuing clinical role postadmission was challenging. Future studies should consider whether interdisciplinary training is needed to enable more radical extension of professional boundaries for paramedics.