Contemporary Prehospital Emergency Medical Services Response Times for Suspected Stroke in the United States

Artificial intelligence to enhance prehospital stroke diagnosis and triage: a perspective

As health systems organize to deliver the highest quality stroke care to their patients, there is increasing emphasis being placed on prehospital stroke recognition, accurate diagnosis, and efficient triage to improve outcomes after stroke. Emergency medical services (EMS) personnel currently rely heavily on dispatch accuracy, stroke screening tools, bypass protocols and prehospital notification to care for patients with suspected stroke, but novel tools including mobile stroke units and telemedicine-enabled ambulances are already changing the landscape of prehospital stroke care. Herein, the authors provide our perspective on the current state of prehospital stroke diagnosis and triage including several of these emerging trends. Then, we provide commentary to highlight potential artificial intelligence (AI) applications to improve stroke detection, improve accurate and timely dispatch, enhance EMS training and performance, and develop novel stroke diagnostic tools for prehospital use.

A qualitative exploration of ambulance clinician behaviour and decision making to identify factors influencing on-scene times for suspected stroke patients in North East England

Aims/objectives

Ambulance clinician assessment of suspected stroke patients aims to provide rapid access to specialist care, however regional and national data show increasing pre-hospital times. This study explored paramedic views about factors contributing to on-scene time (OST) for suspected stroke patients, with a view to identifying opportunities for future interventions, to reduce OST.

Methods

Views of paramedics from one regional service on factors influencing OST were explored using a qualitative approach. Semi-structured interviews with volunteers were recorded, transcribed and analysed using thematic analysis.

Results

Interviews were conducted with 13 paramedics between August and November 2021. Five interlinked themes were identified and described a range of factors influencing OST: 'Initial assessment and sources of information' describes how clinicians make assessments based on initial presentation, influenced by pre-arrival information from ambulance control and family members / bystanders at the scene, and how this influences OST.'Suitability for treatment and interventions' describes how paramedics consider actions such as the face, arms, speech test, cannulation, electrocardiograms and neurological assessments while recognising that pre-hospital interventions for suspected stroke are limited.'The environment' describes the influence of incident setting on OST, including the overall process needed to transport the patient to appropriate care.'Hospital interactions' describes how interactions with hospital staff influenced paramedic actions and OST.'Changing practice' describes the influence of experience and interaction with hospital staff leading to changes in paramedic practice over time.

Conclusion

This study provides insight into how UK paramedics spend time on scene with stroke patients. Multiple factors influencing OST were identified which signpost opportunities for interventions designed to reduce OST. Standardising on-scene assessments for stroke patients, refining communication processes between ambulance services and hospital stroke services and increasing availability of stroke continuing professional development for paramedics were all identified as potential targets for improving OST.

A hybrid strategy using an ambulance and a helicopter to convey thrombectomy candidates to definite care: a prospective observational study

BACKGROUND

Mechanical thrombectomy is the treatment of choice for large vessel occlusion strokes done only in comprehensive stroke centres (CSC). We investigated whether the transportation time of thrombectomy candidates from another hospital district could be reduced by using an ambulance and a helicopter and how this affected their recovery.

METHODS

We prospectively gathered the time points of thrombectomy candidates referred to the Tampere University Hospital from the hospital district of Southern Ostrobothnia. Primary and secondary transports were included. In Hybrid transport, the helicopter emergency medical services (HEMS) unit flew from an airport near the CSC to meet the patient during transport and continued the transport to definitive care. Ground transport was chosen only when the weather prevented flying, or the HEMS crew was occupied in another emergency. We contacted the patients treated with mechanical thrombectomy 90 days after the intervention and rated their recovery with the modified Rankin Scale (mRS). Favourable recovery was considered mRS 0-2.

RESULTS

During the study, 72 patients were referred to the CSC, 71% of which were first diagnosed at the PSC. Hybrid transport (n = 34) decreased the median time from the start of transport from the PSC to the computed tomography (CT) at the CSC when compared to Ground (n = 17) transport (84 min, IQR 82-86 min vs. 109 min, IQR 104-116 min, p < 0.001). The transport times straight from the scene to CT at the CSC were equal: median 93 min (IQR 80-102 min) in the Hybrid group (n = 11) and 97 min (IQR 91-108 min) in the Ground group (n = 10, p = 0.28). The percentages of favourable recovery were 74% and 50% in the Hybrid and Ground transport groups (p = 0.38) from the PSC. Compared to Ground transportation from the scene, Hybrid transportation had less effect on the positive recovery percentages of 60% and 50% (p = 1.00), respectively.

CONCLUSION

Adding a HEMS unit to transporting a thrombectomy candidate from a PSC to CSC decreases the transport time compared to ambulance use only. This study showed minimal difference in the recovery after thrombectomy between Hybrid and Ground transports.

Development of novel optical character recognition system to reduce recording time for vital signs and prescriptions: A simulation-based study

Digital advancements can reduce the burden of recording clinical information. This intra-subject experimental study compared the time and error rates for recording vital signs and prescriptions between an optical character reader (OCR) and manual typing. This study was conducted at three community hospitals and two fire departments in Japan. Thirty-eight volunteers (15 paramedics, 10 nurses, and 13 physicians) participated in the study. We prepared six sample pictures: three ambulance monitors for vital signs (normal, abnormal, and shock) and three pharmacy notebooks that provided prescriptions (two, four, or six medications). The participants recorded the data for each picture using an OCR or by manually typing on a smartphone. The outcomes were recording time and error rate defined as the number of characters with omissions or misrecognitions/misspellings of the total number of characters. Data were analyzed using paired Wilcoxon signed-rank sum and McNemar's tests. The recording times for vital signs were similar between groups (normal state, 21 s [interquartile range (IQR), 17-26 s] for OCR vs. 23 s [IQR, 18-31 s] for manual typing). In contrast, prescription recording was faster with the OCR (e.g., six-medication list, 18 s [IQR, 14-21 s] for OCR vs. 144 s [IQR, 112-187 s] for manual typing). The OCR had fewer errors than manual typing for both vital signs and prescriptions (0/1056 [0%] vs. 14/1056 [1.32%]; p<0.001 and 30/4814 [0.62%] vs. 53/4814 [1.10%], respectively). In conclusion, the developed OCR reduced the recording time for prescriptions but not vital signs. The OCR showed lower error rates than manual typing for both vital signs and prescription data.

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.

Effect of the COVID-19 pandemic on advanced life support units' prehospital management of the stroke code in four Spanish regions: an observational study

INTRODUCTION

Stroke is the most common time-dependent pathology that pre-hospital emergency medical services (EMS) are confronted with. Prioritisation of ambulance dispatch, initial actions and early pre-notification have a major impact on mortality and disability. The COVID-19 pandemic has led to disruptions in the operation of EMS due to the implementation of self-protection measures and increased demand for care. It is crucial to evaluate what has happened to draw the necessary conclusions and propose changes to improve the system's strength for the future. The study aims to compare prehospital time and neuroprotective care metrics for acute stroke patients during the first wave of COVID-19 and the same periods in the years before and after.

METHODS

Analytical, observational, multicentre study conducted in the autonomous communities of Andalusia, Catalonia, Galicia, and Madrid in the pre-COVID-19 (2019), "first wave" of COVID-19 (2020) and post-COVID-19 (2021) periods. Consecutive non-randomized sampling. Descriptive statistical analysis and hypothesis testing to compare the three time periods, with two by two post-hoc comparisons, and multivariate analysis.

RESULTS

A total of 1,709 patients were analysed. During 2020 there was a significant increase in attendance time of 1.8 min compared to 2019, which was not recovered in 2021. The time of symptom onset was recorded in 82.8% of cases, and 83.3% of patients were referred to specialized stroke centres. Neuroprotective measures (airway, blood glucose, temperature, and blood pressure) were performed in 43.6% of patients.

CONCLUSION

During the first wave of COVID-19, the on-scene times of pre-hospital emergency teams increased while keeping the same levels of neuroprotection measures as in the previous and subsequent years. It shows the resilience of EMS under challenging circumstances such as those experienced during the pandemic.

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.

Prehospital Stroke Care Part 1: Emergency Medical Services and the Stroke Systems of Care

Acute stroke care begins before hospital arrival, and several prehospital factors are critical in influencing overall patient care and poststroke outcomes. This topical review provides an overview of the state of the science on prehospital components of stroke systems of care and how emergency medical services systems may interact in the system to support acute stroke care. Topics include layperson recognition of stroke, prehospital transport strategies, networked stroke care, systems for data integration and real-time feedback, and inequities that exist within and among systems.

The quality disparity of stroke care over time: An analysis based on the national dataset from 2011 to 2017

BACKGROUND

Adherence to evidence-based hospital stroke care is variable and may change over time. It is important to determine which process measures are associated with variation in outcome. In a large dataset, we analyzed the association between process and outcome and the fluctuations of indicators over time, and identified quality indicators (QIs) that should be prioritized for improving the quality of stroke care.

METHODS

We analyzed data from 123,259 patients diagnosed with acute ischemic stroke (AIS) who were treated at 109 large tertiary hospitals in China between January 2011 and May 2017. In total, 12 stroke treatment indicators were selected to calculate the hospital process composite performance (HPCP). Hospitals were divided into subgroups according to the time trend of HPCP estimated by the Group-Based Model. We analyzed the influence of hospital subgroups on the patient outcomes using a multi-level model and explored the QIs that led to variation.

RESULTS

The HPCP trends for stroke indicators of 109 hospitals over 7 years were divided into two groups (Group 1, low-HPCP; Group 2, high-HPCP). After adjusting for patient age, medical insurance, comorbidities, patterns of admission, and NIHSS-scores, patients in the high-HPCP group presented higher rate of independence and longer length of stay compared to the low-HPCP group. The multi-level model showed that there was a statistically significant difference in the utilization rate between the two groups, with most marked differences seen in emergency assessment and function evaluation indicators.

CONCLUSION

Variation in the quality of stroke care exists across hospitals, and better adherence to guideline-based care is associated with improved outcomes. We found that QIs related to emergency examination and functional assessment were the main factors differing between good and poor adherers to stroke indicators, suggesting that quality improvement in stroke care could prioritize these QIs.

Community socioeconomic and urban-rural differences in emergency medical services times for suspected stroke in North Carolina

OBJECTIVE

Our objectives were to describe time intervals of EMS encounters for suspected stroke patients in North Carolina (NC) and evaluate differences in EMS time intervals by community socioeconomic status (SES) and rurality.

METHODS

This cross-sectional study used statewide data on EMS encounters of suspected stroke in NC in 2019. Eligible patients were adults requiring EMS transport to a hospital following a 9-1-1 call for stroke-like symptoms. Incident street addresses were geocoded to census tracts and linked to American Community Survey SES data and to rural-urban commuting area (RUCA) codes. Community SES was defined as high, medium, or low based on tertiles of an SES index. Urban, suburban, and rural tracts were defined by RUCA codes 1, 2-6, and 7-10, respectively. Multivariable quantile regression was used to estimate how the median and 90th percentile of EMS time intervals varied by community SES and rurality, adjusting for each other; patient age, gender, and race/ethnicity; and incident characteristics.

RESULTS

We identified 17,117 eligible EMS encounters of suspected stroke from 2028 census tracts. The population was 65% 65+ years old; 55% female; and 69% Non-Hispanic White. Median response, scene, and transport times were 8 (interquartile range, IQR 6-11) min, 16 (IQR 12-20) min, and 14 (IQR 9-22) minutes, respectively. In quantile regression adjusted for patient demographics, minimal differences were observed for median response and scene times by community SES and rurality. The largest median differences were observed for transport times in rural (6.7 min, 95% CI 5.8, 7.6) and suburban (4.7 min, 95% CI 4.2, 5.1) tracts compared to urban tracts. Adjusted rural-urban differences in 90th percentile transport times were substantially greater (16.0 min, 95% CI 14.5, 17.5). Low SES was modesty associated with shorter median (-3.3 min, 95% CI -3.8, -2.9) and 90th percentile (-3.0 min, 95% CI -4.0, -2.0) transport times compared to high SES tracts.

CONCLUSIONS

While community-level factors were not strongly associated with EMS response and scene times for stroke, transport times were significantly longer rural tracts and modestly shorter in low SES tracts, accounting for patient demographics. Further research is needed on the role of community socioeconomic deprivation and rurality in contributing to delays in prehospital stroke care.

Disparities in Emergency Medical Services Care Delivery in the United States: A Scoping Review

BACKGROUND

Emergency medical services (EMS) often serve as the first medical contact for ill or injured patients, representing a critical access point to the health care delivery continuum. While a growing body of literature suggests inequities in care within hospitals and emergency departments, limited research has comprehensively explored disparities related to patient demographic characteristics in prehospital care.

OBJECTIVE

We aimed to summarize the existing literature on disparities in prehospital care delivery for patients identifying as members of an underrepresented race, ethnicity, sex, gender, or sexual orientation group.

METHODS

We conducted a scoping review of peer-reviewed and non-peer-reviewed (gray) literature. We searched PubMed, CINAHL, Web of Science, Proquest Dissertations, Scopus, Google, and professional websites for studies set in the U.S. between 1960 and 2021. Each abstract and full-text article was screened by two reviewers. Studies written in English that addressed the underrepresented groups of interest and investigated EMS-related encounters were included. Studies were excluded if a disparity was noted incidentally but was not a stated objective or discussed. Data extraction was conducted using a standardized electronic form. Results were summarized qualitatively using an inductive approach.

RESULTS

One hundred forty-five full-text articles from the peer-reviewed literature and two articles from the gray literature met inclusion criteria: 25 studies investigated sex/gender, 61 studies investigated race/ethnicity, and 58 studies investigated both. One study investigated sexual orientation. The most common health conditions evaluated were out-of-hospital cardiac arrest (n = 50), acute coronary syndrome (n = 36), and stroke (n = 31). The phases of EMS care investigated included access (n = 55), pre-arrival care (n = 46), diagnosis/treatment (n = 42), and response/transport (n = 40), with several studies covering multiple phases. Disparities were identified related to all phases of EMS care for underrepresented groups, including symptom recognition, pain management, and stroke identification. The gray literature identified public perceptions of EMS clinicians' cultural competency and the ability to appropriately care for transgender patients in the prehospital setting.

CONCLUSIONS

Existing research highlights health disparities in EMS care delivery throughout multiple health outcomes and phases of EMS care. Future research is needed to identify structured mechanisms to eliminate disparities, address clinician bias, and provide high-quality equitable care for all patient populations.

Cortical symptoms described in emergency calls for patients with suspected large vessel occlusion: a descriptive analysis of 157 emergency calls

Background

Emergency medical dispatchers typically use the dispatch code for suspected stroke when the caller brings up one or more symptoms from the face-arm-speech triad. Paramedics and emergency department physicians are trained to suspect large vessel occlusion stroke when the stroke patient presents with hemiparesis and cortical symptoms: neglect, aphasia, and conjugate eye deviation (CED). We hypothesized that these symptoms could be evident in the emergency call.

In this study, we aimed to describe common symptoms mentioned in the emergency calls for paramedic-suspected thrombectomy candidates. Secondly, we wanted to explore how the question about CED arises in the Finnish suspected stroke dispatch protocol. Our third aim was to find out if the symptoms brought up in suspected stroke and non-stroke dispatches differed from each other.

Methods

This was a retrospective study with a descriptive analysis of emergency calls for patients with paramedic-suspected large vessel occlusion stroke. We listened to the emergency calls for 157 patients transported to Tampere University Hospital, a Finnish comprehensive stroke centre. Two researchers listened for symptoms brought up in these calls and filled out a pre-planned case report form.

Results

Speech disturbance was the most common symptom brought up in 125 (80%) calls. This was typically described as an inability to speak any words (n = 65, 52% of calls with speech disturbance). Other common symptoms were falling down (n = 63, 40%) and facial asymmetry (n = 41, 26%). Suspicion of stroke was mentioned by 44 (28%) callers. When the caller mentioned unconsciousness the emergency dispatcher tended to use a non-stroke dispatch code. The dispatchers adhered poorly to the protocol and asked about CED in only 57% of suspected stroke dispatches. We found CED in 12 emergency calls and ten of these patients were diagnosed with large vessel occlusion.

Conclusion

In cases where paramedics suspected large vessel occlusion stroke, typical stroke symptoms were described during the emergency call. Speech disturbance was typically described as inability to say anything. It is possible to further develop suspected stroke dispatch protocols to recognize thrombectomy candidates from ischemic cortical signs such as global aphasia and CED.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12873-022-00706-5.

Analysis of Stroke Care Among 2019-2020 National Emergency Medical Services Information System Encounters

OBJECTIVES

Emergency Medicine Service (EMS) providers play a pivotal role in early identification and initiation of treatment for stroke. The objective of this study is to characterize nationwide EMS practices for suspected stroke and assess for gender-based differences in compliance with American Stroke Association (ASA) guidelines.

MATERIALS AND METHODS

Using the 2019-2020 National Emergency Medical Services Information System (NEMSIS) Datasets, we identified encounters with an EMS designated primary impression of stroke. We characterized patient characteristics and EMS practices and assessed compliance with eight metrics for "guideline-concordant" care. Multivariable logistic regression modeled the association between gender and the primary outcome (guideline-concordant care), adjusted for age, EMS level of service, EMS geographical region, region type (i.e. urban or rural), and year.

RESULTS

Of 693,177 encounters with a primary impression of stroke, overall compliance with each performance metric ranged from 18% (providing supplemental oxygen when the pulse oximetry is less than 94%) to 76% (less than 90sec from incoming call to EMS dispatch). 2,382 (0.39%) encounters were fully guideline-concordant. Women were significantly less likely than men to receive guideline-concordant care (adjusted OR 0.82, 95% CI 0.75-0.89; 0.36% women, 0.43% men with guideline-concordant care).

CONCLUSIONS

A minority of patients received prehospital stroke care that was documented to be compliant with ASA guidelines. Women were less likely to receive fully guideline-compliant care compared to men, after controlling for confounders, although the difference was small and of uncertain climical importance. Further studies are needed to evaluate the underlying reasons for this disparity, its impact on patient outcomes, and to identify potential targeted interventions to improve prehospital stroke care.

Influence of hospital capabilities and prehospital time on outcomes of thrombectomy for stroke in Japan from 2013 to 2016

To determine whether increasing thrombectomy-capable hospitals with moderate comprehensive stroke center (CSC) capabilities is a valid alternative to centralization of those with high CSC capabilities. This retrospective, nationwide, observational study used data from the J-ASPECT database linked to national emergency medical service (EMS) records, captured during 2013–2016. We compared the influence of mechanical thrombectomy (MT) use, the CSC score, and the total EMS response time on the modified Rankin Scale score at discharge among patients with acute ischemic stroke transported by ambulance, in phases I (2013–2014, 1461 patients) and II (2015–2016, 3259 patients). We used ordinal logistic regression analyses to analyze outcomes. From phase I to II, MTs increased from 2.7 to 5.5%, and full-time endovascular physicians per hospital decreased. The CSC score and EMS response time remained unchanged. In phase I, higher CSC scores were associated with better outcomes (1-point increase, odds ratio [95% confidence interval]: 0.951 [0.915–0.989]) and longer EMS response time was associated with worse outcomes (1-min increase, 1.007 [1.001–1.013]). In phase II, neither influenced the outcomes. During the transitional shortage of thrombectomy-capable hospitals, increasing hospitals with moderate CSC scores may increase nationwide access to MT, improving outcomes.

Emergency Medical Service Time Intervals for Patients With Suspected Stroke in the United States

BACKGROUND

Optimal care for patients with stroke relies on timely recognition and rapid transport to appropriate treatment, often by emergency medical services (EMS). Our primary objective was to describe EMS time intervals for patients with suspected stroke in the United States. We also sought to quantify the variation in EMS time intervals by geographic location and urbanicity.

METHODS

We conducted a cross-sectional evaluation of EMS 9-1-1 activations (ie, calls for service) included in the 2018 and 2019 National EMS Information System datasets. We included ground or air EMS activations for a 9-1-1 scene response where a patient aged ≥18 years with suspected stroke was treated and transported by EMS. Time intervals for dispatch, response, scene, transport, and total prehospital time (ie, from dispatch to hospital arrival) were calculated, stratified by ground and air transport type.

RESULTS

A total of 410 187 activations for suspected stroke were included, of which 98% were a ground transport. The median total prehospital time for ground transports was 35 minutes (interquartile range, 27-45, 90th percentile 58). Median total prehospital time for air transports was substantially longer at 56 minutes (interquartile range, 43-70, 90th percentile 86). Times varied by Census division and urbanicity with the shortest ground total prehospital times in the East North Central division and urban areas and longest times in the East South Central and rural and frontier areas.

CONCLUSIONS

Timely EMS response and transport is critical for optimizing care of patients with suspected stroke. Using a large, national dataset of EMS activations, we found variations by geographic location and urbanicity in total prehospital time for ground and air EMS activations for patients with stroke.

Association between dispatch complaint and critical prehospital time intervals in suspected stroke 911 activations in the National Emergency Medical Services Information System, 2012-2016

OBJECTIVE

Emergency Medical Services can help improve stroke outcomes by recognizing stroke symptoms, establishing response priority for 911 calls, and minimizing prehospital delays. This study examines 911 stroke events and evaluates associations between events dispatched as stroke and critical EMS time intervals.

MATERIALS AND METHODS

Data from the National Emergency Medical Services Information System, 2012 to 2016, were analyzed. Activations from 911 calls with a primary or secondary provider impression of stroke were included for adult patients transported to a hospital destination. Three prehospital time intervals were evaluated: (1) response time (RT) ≤8 min, (2) on-scene time (OST) ≤15 min, and (3) transport time (TT) ≤12 min. Associations between stroke dispatch complaint and prehospital time intervals were assessed using multivariate regression to estimate adjusted risk ratios (ARR) and 95% confidence intervals (CIs).

RESULTS

Approximately 37% of stroke dispatch complaints were identified by EMS as a suspected stroke. Compared to stroke events without a stroke dispatch complaint, median OST was shorter for events with a stroke dispatch (16 min vs. 14 min, respectively). In adjusted analyses, events dispatched as stroke were more likely to meet the EMS time benchmark for OST ≤15 min (OST, 1.20 [1.20-1.21]), but not RT or TT (RT, [1.00-1.01]; TT, 0.95 [0.94-0.95]).

CONCLUSIONS

Our results indicate that dispatcher recognition of stroke symptoms reduces the time spent on-scene by EMS personnel. These findings can inform future EMS stroke education and quality improvement efforts to emphasize dispatcher recognition of stroke signs and symptoms, as EMS dispatchers play a crucial role in optimizing the prehospital response.

Geographical Distribution of Emergency Services Times in Traffic Accidents in Extremadura

Objective: To analyze the response time and transport time taken by the emergency medical services (EMS), considering their urban or rural location, to attend traffic accident casualties that occurred in the different geographical areas of Extremadura (Spain) from 2012 to 2015. Methods: This was a cross-sectional study of the data recorded by the Emergency Response Coordination Center 112 (ERCC-112) from traffic accidents attended by EMS. Response time was defined as the time elapsed from the request-for-care receipt until arrival of the EMS at the accident scene, and transport time as that from leaving the scene until arrival to the referral hospital. Rural EMS were those based in locations where there is no hospital, and urban EMS those located in towns or cities with a hospital. Results: During the 4-year period studied, 5,572 traffic accidents requested assistance through the ERCC-112. From the 2,875 accidents (51.9%) in which EMS were mobilized, 55.4% occurred in urban roads and the remaining in interurban ones. A total of 113 people (mean age 48.4 ± 19.0 years, range 15–84 years) died at the accident scene or before arrival to the hospital, 88.5% of them in interurban accidents. The average response time of urban and rural EMS was 10.7 ± 7.3 and 18.0 ± 12.6 min (p < 0.001), respectively, and the average transport time was 13.2 ± 11.7 and 45.2 ± 25.0 min (p = 0.009). Response time was longer than the 30-min optimum only in the most peripheral areas of Extremadura, while transport time exceeded the optimum of 90 min in the eastern regions of two health areas (Cáceres and Don Benito-Villanueva). 19.1% of the victims attended by rural EMS were classified as having a serious prognosis or as having died, as compared with 11.2% (p = 0.048) of those attended by urban EMS. Conclusions: The geographical location of EMS in Extremadura (Spain) guarantees adequate response times in traffic accidents, both in rural and urban areas. However, recommended transport times were occasionally exceeded in the most peripheral areas, due to hospital location.

Ambulance service call handler and clinician identification of stroke in North East Ambulance Service

Introduction:

Emergency medical services (EMS) are the first point of contact for most acute stroke patients. The EMS response is triggered by ambulance call handlers who triage calls and then an appropriate response is allocated. Early recognition of stroke is vital to minimise the call to hospital time as the availability and effectiveness of reperfusion therapies are time dependent. Minimising the pre-hospital phase by accurate call handler stroke identification, short EMS on-scene times and rapid access to specialist stroke care is vital. The aims of this study were to evaluate stroke identification by call handlers and clinicians in North East Ambulance Service (NEAS) and report on-scene times for suspected stroke patients.

Methods:

A retrospective service evaluation was conducted linking routinely collected data between 1 and 30 November 2019 from three sources: NEAS Emergency Operations Centre; NEAS clinicians; and hospital stroke diagnoses.

Results:

The datasets were linked resulting in 2214 individual cases. Call handler identification of acute stroke was 51.5% (95% CI 45.3–57.8) sensitive with a positive predictive value (PPV) of 12.8% (95% CI 11.4–14.4). Face-to-face clinician identification of stroke was 76.1% (95% CI 70.4–81.1) sensitive with a PPV of 27.4% (95% CI 25.3–29.7). The median on-scene time was 33 (IQR 25–43) minutes, with call handler and clinician identification of stroke resulting in shorter times.

Conclusion:

This service evaluation using ambulance data linked with national audit data showed that the sensitivity of NEAS call handler and clinician identification of stroke are similar to figures published on other systems but the PPV of call handler and clinician identification stroke could be improved. However, sensitivity is paramount while timely identification of suspected stroke patients and rapid transport to definitive care are the primary functions of EMS. Call handler identification of stroke appears to affect the time that clinicians spend at scene with suspected stroke patients.

Time Is Brain: Prehospital Emergency Medical Services Response Times for Suspected Stroke and Effects of Prehospital Interventions

OBJECTIVES

To compare prehospital time for patients with suspected stroke in Florida with the American Stroke Association (ASA) time benchmarks, and to investigate the effects of dispatch notification and stroke assessment scales on prehospital time.

PATIENTS AND METHODS

A retrospective analysis was performed using data from Florida's Emergency Medical Services Tracking and Reporting System database. All patients with suspected stroke transported to a treatment center from January 1, 2018, through December 31, 2018, were analyzed. Time intervals from 911 call to hospital arrival were evaluated and compared with ASA benchmarks.

RESULTS

In 2018, 11,577 patients with suspected stroke were transported to a hospital (mean age, 71.5±15.7 years; 51.5% women). The median alarm-to-hospital time was 33.98 minutes (27.8 to 41.4), with a total emergency medical services (EMS) time of 32.30 minutes (26.5 to 39.478). The on-scene time was the largest time interval with a median of 13.28 minutes (10.0 to 17.4). Emergency medical services encounters met the ASA benchmarks for time in 58% to 62% of the EMS encounters in Florida (recommended 90%; P<.001). The total EMS time was reduced when a stroke notification was reported by the dispatch center (32.00 minutes vs 32.62 minutes; P=.006) or when a stroke assessment scale was used by the EMS personnel (31.88 minutes vs 32.96 minutes; P=.005).

CONCLUSION

This study reveals a substantial opportunity for improvement in stroke care in Florida. Two prehospital EMS stroke interventions seem to reduce prehospital time for patients with suspected stroke. Adoption of these interventions might improve the stroke systems of care.

Prehospital time intervals and management of ischemic stroke patients

OBJECTIVE

Quantify prehospital time intervals, describe prehospital stroke management, and estimate potential time saved if certain procedures were performed en route to the emergency department (ED).

METHODS

Acute ischemic stroke patients who arrived via emergency medical services (EMS) between 2012 and 2016 were identified. We determined the following prehospital time intervals: chute, response, on-scene, transport, and total prehospital times. Proportions of patients receiving the following were determined: Cincinnati Prehospital Stroke Scale (CPSS) assessment, prenotification, glucose assessment, vascular access, and 12-lead electrocardiography (ECG). For glucose assessment, ECG acquisition, and vascular access, the location (on-scene vs. en route) in which they were performed was described. Difference in on-scene times among patients who had these three interventions performed on-scene vs. en route was assessed.

RESULTS

Data from 870 patients were analyzed. Median total prehospital time was 39 min and comprised the following: chute time: 1 min; response time: 9 min; on-scene time: 15 min; and transport time: 14 min. CPSS was assessed in 64.7% of patients and prenotification was provided for 52.0% of patients. Glucose assessment, vascular access initiation, and ECG acquisition was performed on 84.1%, 72.6%, and 67.2% of patients, respectively. 59.0% of glucose assessments, 51.2% of vascular access initiations, and 49.8% of ECGs were performed on-scene. On-scene time was 9 min shorter among patients who had glucose assessments, vascular access initiations, and ECG acquisitions all performed en route vs. on-scene.

CONCLUSIONS

On-scene time comprised 38.5% of total prehospital time. Limiting on-scene performance of glucose assessments, vascular access initiations, and ECG acquisitions may decrease prehospital time.

Guidelines for the Early Management of Patients With Acute Ischemic Stroke: 2019 Update to the 2018 Guidelines for the Early Management of Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

Background and Purpose- The purpose of these guidelines is to provide an up-to-date comprehensive set of recommendations in a single document for clinicians caring for adult patients with acute arterial ischemic stroke. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators. These guidelines supersede the 2013 Acute Ischemic Stroke (AIS) Guidelines and are an update of the 2018 AIS Guidelines. Methods- Members of the writing group were appointed by the American Heart Association (AHA) Stroke Council's Scientific Statements Oversight Committee, representing various areas of medical expertise. Members were not allowed to participate in discussions or to vote on topics relevant to their relations with industry. An update of the 2013 AIS Guidelines was originally published in January 2018. This guideline was approved by the AHA Science Advisory and Coordinating Committee and the AHA Executive Committee. In April 2018, a revision to these guidelines, deleting some recommendations, was published online by the AHA. The writing group was asked review the original document and revise if appropriate. In June 2018, the writing group submitted a document with minor changes and with inclusion of important newly published randomized controlled trials with >100 participants and clinical outcomes at least 90 days after AIS. The document was sent to 14 peer reviewers. The writing group evaluated the peer reviewers' comments and revised when appropriate. The current final document was approved by all members of the writing group except when relationships with industry precluded members from voting and by the governing bodies of the AHA. These guidelines use the American College of Cardiology/AHA 2015 Class of Recommendations and Level of Evidence and the new AHA guidelines format. Results- These guidelines detail prehospital care, urgent and emergency evaluation and treatment with intravenous and intra-arterial therapies, and in-hospital management, including secondary prevention measures that are appropriately instituted within the first 2 weeks. The guidelines support the overarching concept of stroke systems of care in both the prehospital and hospital settings. Conclusions- These guidelines provide general recommendations based on the currently available evidence to guide clinicians caring for adult patients with acute arterial ischemic stroke. In many instances, however, only limited data exist demonstrating the urgent need for continued research on treatment of acute ischemic stroke.

Field triage for endovascular stroke therapy: a population-based comparison

Background

Endovascular therapy (EVT) for stroke improves outcomes but is time sensitive.

Objective

To compare times to treatment and outcomes between patients taken to the closest primary stroke center (PSC) with those triaged in the field to a more distant comprehensive stroke center (CSC).

Methods

During the study, a portion of our region allowed field triage of patients who met severity criteria to a more distant CSC than the closest PSC. The remaining patients were transported to the closest PSC. We compared times to treatment and clinical outcomes between those two groups. Additionally, we performed a matched-pairs analysis of patients from both groups on stroke severity and distance to CSC.

Results

Over 2 years, 232 patients met inclusion criteria and were closest from the field to a PSC; 144 were taken to the closest PSC and 88 to the more distant CSC. The median additional transport time to the CSC was 7 min. Times from scene departure to alteplase and arterial puncture were faster in the direct group (50 vs 62 min; 93 vs 152 min; p<0.001 for both). Among patients who were independent before the stroke, the OR for less disability in the direct group was 1.47 (95% CI 1.13 to 1.93, p=0.003), and 2.06 (95% CI 1.10 to 3.89, p=0.01) for the matched pairs.

Conclusions

In a densely populated setting, for patients with stroke who are EVT candidates and closest to a PSC from the field, triage to a slightly more distant CSC is associated with faster time to EVT, no delay to alteplase, and less disability at 90 days.

Call to hospital times for suspected stroke patients in the North East of England: a service evaluation

Introduction:

Stroke is a leading cause of mortality and morbidity. The role of the ambulance service in acute stroke care focuses on recognition followed by rapid transport to specialist care. The treatment options for acute ischaemic strokes are time dependent, so minimising the pre-hospital phase of care is important. The aim of this service evaluation was to report historical pre-hospital times for suspected stroke patients transported by the North East Ambulance Service NHS Foundation Trust (NEAS) and identify areas for improvement.

Methods:

This was a retrospective service evaluation using routinely collected data. Data on overall call to hospital times, call to arrival times, on scene times and leave scene to hospital are reported.

Results:

Data on 24,070 patients with an impression of stroke transported by NEAS between 1 April 2011 and 31 May 2018 are reported. The median call to hospital time increased from 41 to 68 minutes, call to arrival from 7 to 17 minutes, on scene from 20 to 30 minutes and leave to hospital from 12 to 15 minutes.

Conclusion:

The pre-hospital call to hospital time for stroke patients increased between 2011 and 2018. The call to arrival phase saw a sharp increase between 2015 and 2017, whereas on scene and leave scene to hospital saw steadier increases. Increasing demand on the ambulance service, reorganisation of regional stroke services and other factors may have contributed to the increase in times. Reducing the on scene phase of pre-hospital stroke care would lead to patient benefits and is the area where ambulance clinicians have the most influence.

Recommendations for the Establishment of Stroke Systems of Care: A 2019 Update

In 2005, the American Stroke Association published recommendations for the establishment of stroke systems of care and in 2013 expanded on them with a statement on interactions within stroke systems of care. The aim of this policy statement is to provide a comprehensive review of the scientific evidence evaluating stroke systems of care to date and to update the American Stroke Association recommendations on the basis of improvements in stroke systems of care. Over the past decade, stroke systems of care have seen vast improvements in endovascular therapy, neurocritical care, and stroke center certification, in addition to the advent of innovations, such as telestroke and mobile stroke units, in the context of significant changes in the organization of healthcare policy in the United States. This statement provides an update to prior publications to help guide policymakers and public healthcare agencies in continually updating their stroke systems of care in light of these changes. This statement and its recommendations span primordial and primary prevention, acute stroke recognition and activation of emergency medical services, triage to appropriate facilities, designation of and treatment at stroke centers, secondary prevention at hospital discharge, and rehabilitation and recovery.

2018 Guidelines for the Early Management of Patients With Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

BACKGROUND AND PURPOSE

The purpose of these guidelines is to provide an up-to-date comprehensive set of recommendations for clinicians caring for adult patients with acute arterial ischemic stroke in a single document. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators. These guidelines supersede the 2013 guidelines and subsequent updates.

METHODS

Members of the writing group were appointed by the American Heart Association Stroke Council's Scientific Statements Oversight Committee, representing various areas of medical expertise. Strict adherence to the American Heart Association conflict of interest policy was maintained. Members were not allowed to participate in discussions or to vote on topics relevant to their relations with industry. The members of the writing group unanimously approved all recommendations except when relations with industry precluded members voting. Prerelease review of the draft guideline was performed by 4 expert peer reviewers and by the members of the Stroke Council's Scientific Statements Oversight Committee and Stroke Council Leadership Committee. These guidelines use the American College of Cardiology/American Heart Association 2015 Class of Recommendations and Levels of Evidence and the new American Heart Association guidelines format.

RESULTS

These guidelines detail prehospital care, urgent and emergency evaluation and treatment with intravenous and intra-arterial therapies, and in-hospital management, including secondary prevention measures that are appropriately instituted within the first 2 weeks. The guidelines support the overarching concept of stroke systems of care in both the prehospital and hospital settings.

CONCLUSIONS

These guidelines are based on the best evidence currently available. In many instances, however, only limited data exist demonstrating the urgent need for continued research on treatment of acute ischemic stroke.

Emergency Dispatcher Stroke Recognition: Associations with Downstream Care

OBJECTIVE

As the first point of contact for patients activating emergency medical services (EMS), emergency dispatchers have the earliest opportunity to recognize stroke. We sought to quantify dispatcher stroke recognition and its relationships with EMS stroke recognition and response speed.

METHODS

We assembled a cohort of consecutive EMS-transported patients with a dispatcher suspected stroke or a hospital discharge diagnosis of stroke or transient ischemic attack (TIA). Dispatcher sensitivity and positive predictive value (PPV) for stroke recognition were calculated. Multivariable logistic regression analysis was used to determine predictors of dispatcher recognition and relationships between dispatcher recognition and downstream care.

RESULTS

During a 12-month period, 601 patients met inclusion criteria. Dispatchers suspected stroke in 229/324 (sensitivity = 70.7% [65.5 to 75.4%]) confirmed stroke/TIA cases and correctly assigned a suspected stroke label in 229/506 cases (PPV = 45.3% [41.0 to 49.6%]). Dispatchers had higher odds of recognizing ischemic strokes (aOR 3.4 [1.4 to 8.5]) and lower odds of recognizing patients with visual deficits (aOR = 0.4 [0.2 to 0.9]) or vomiting (aOR = 0.3 [0.1 to 0.9]). Dispatcher suspected stroke cases received more on-scene stroke screens (79.0% vs. 54.7%, p < 0.0001) and were more often recognized by EMS as strokes (77.7% vs. 57.9%, p = 0.0005). Dispatcher recognition was independently associated with EMS stroke recognition (aOR = 3.8 [1.9 to 7.7]), but not with transportation times, door-to-CT times, or t-PA delivery.

CONCLUSIONS

Emergency dispatcher stroke recognition is associated with higher rates of on-scene stroke scale performance and EMS ischemic stroke recognition but not with reduced transport times, door-to-CT times, or t-PA treatment.

Estimated Impact of Emergency Medical Service Triage of Stroke Patients on Comprehensive Stroke Centers: An Urban Population-Based Study

BACKGROUND AND PURPOSE

The American Stroke Association recommends that Emergency Medical Service bypass acute stroke-ready hospital (ASRH)/primary stroke center (PSC) for comprehensive stroke centers (CSCs) when transporting appropriate stroke patients, if the additional travel time is ≤15 minutes. However, data on additional transport time and the effect on hospital census remain unknown.

METHODS

Stroke patients ≥20 years old who were transported from home to an ASRH/PSC or CSC via Emergency Medical Service in 2010 were identified in the Greater Cincinnati area population of 1.3 million. Addresses of all patients' residences and hospitals were geocoded, and estimated travel times were calculated. We estimated the mean differences between the travel time for patients taken to an ASRH/PSC and the theoretical time had they been transported directly to the region's CSC.

RESULTS

Of 929 patients with geocoded addresses, 806 were transported via Emergency Medical Service directly to an ASRH/PSC. Mean additional travel time of direct transport to the CSC, compared with transport to an ASRH/PSC, was 7.9±6.8 minutes; 85% would have ≤15 minutes added transport time. Triage of all stroke patients to the CSC would have added 727 patients to the CSC's census in 2010. Limiting triage to the CSC to patients with National Institutes of Health Stroke Scale score of ≥10 within 6 hours of onset would have added 116 patients (2.2 per week) to the CSC's annual census.

CONCLUSIONS

Emergency Medical Service triage to CSCs based on stroke severity and symptom duration may be feasible. The impact on stroke systems of care and patient outcomes remains to be determined and requires prospective evaluation.

Identifying Key Words in 9-1-1 Calls for Stroke: A Mixed Methods Approach

OBJECTIVES

Identifying stroke during a 9-1-1 call is critical to timely prehospital care. However, emergency medical dispatchers (EMDs) recognize stroke in less than half of 9-1-1 calls, potentially due to the words used by callers to communicate stroke signs and symptoms. We hypothesized that callers do not typically use words and phrases considered to be classical descriptors of stroke, such as focal neurologic deficits, but that a mixed-methods approach can identify words and phrases commonly used by 9-1-1 callers to describe acute stroke victims.

METHODS

We performed a mixed-method, retrospective study of 9-1-1 call audio recordings for adult patients with confirmed stroke who were transported by ambulance in a large urban city. Content analysis, a qualitative methodology, and computational linguistics, a quantitative methodology, were used to identify key words and phrases used by 9-1-1 callers to describe acute stroke victims. Because a caller's level of emotional distress contributes to the communication during a 9-1-1 call, the Emotional Content and Cooperation Score was scored by a multidisciplinary team.

RESULTS

A total of 110 9-1-1 calls, received between June and September 2013, were analyzed. EMDs recognized stroke in 48% of calls, and the emotional state of most callers (95%) was calm. In 77% of calls in which EMDs recognized stroke, callers specifically used the word "stroke"; however, the word "stroke" was used in only 38% of calls. Vague, non-specific words and phrases were used to describe stroke victims' symptoms in 55% of calls, and 45% of callers used distractor words and phrases suggestive of non-stroke emergencies. Focal neurologic symptoms were described in 39% of calls. Computational linguistics identified 9 key words that were more commonly used in calls where the EMD identified stroke. These words were concordant with terms identified through qualitative content analysis.

CONCLUSIONS

Most 9-1-1 callers used vague, non-specific, or distractor words and phrases and infrequently provide classic stroke descriptions during 9-1-1 calls for stroke. Both qualitative and quantitative methodologies identified similar key words and phrases associated with accurate EMD stroke recognition. This study suggests that tools incorporating commonly used words and phrases could potentially improve EMD stroke recognition.