Sustaining a New Model of Acute Stroke Care: A Mixed-Method Process Evaluation of the Melbourne Mobile Stroke Unit.

BACKGROUND: Internationally, Mobile Stroke Unit (MSU) ambulances have changed pre-hospital acute stroke care delivery. MSU clinical and cost-effectiveness studies are emerging, but little is known about important factors for achieving sustainability of this innovative model of care. METHODS: Mixed-methods study from the Melbourne MSU (operational since November 2017) process evaluation. Participant purposive sampling included clinical, operational and executive/management representatives from Ambulance Victoria (AV) (emergency medical service provider), the MSU clinical team, and receiving hospitals. Sustainability was defined as ongoing MSU operations, including MSU workforce and future model considerations. Theoretically-based on-line survey with Unified Theory of Acceptance and Use of Technology (UTAUT), Self Determination Theory (SDT, Intrinsic Motivation), and open-text questions targeting barriers and benefits was administered (June-September 2019). Individual/group interviews were conducted, eliciting improvement suggestions and requirements for ongoing use. Descriptive and regression analyses (quantitative data) and directed content and thematic analysis (open text and interview data) were conducted. RESULTS: There were 135 surveys completed. Identifying that the MSU was beneficial to daily work (ß=0.61), not experiencing pressure/tension about working on the MSU (ß=0.17) and thinking they did well working within the team model (ß=0.17) were significantly associated with wanting to continue working within the MSU model [R2=0.76; F(15, 60)=12.76, P<.001]. Experiences varied between those on the MSU team and those working with the MSU. Advantages were identified for patients (better, faster care) and clinicians (interdisciplinary learning). Disadvantages included challenges integrating into established systems, and establishing working relationships. Themes identified from 35 interviews were MSU team composition, MSU vehicle design and layout, personnel recruitment and rostering, communication improvements between organisations, telemedicine options, MSU operations and dispatch specificity. CONCLUSION: Important factors affecting the sustainability of the MSU model of stroke care emerged. A cohesive team approach, with identifiable benefits and good communication between participating organisations is important for clinical and operational sustainability.

Cost-effectiveness of tenecteplase versus alteplase for stroke thrombolysis evaluation trial in the ambulance.

BACKGROUND: Tenecteplase administered to patients with ischaemic stroke in a mobile stroke unit (MSU) has been shown to reduce the perfusion lesion volumes and result in ultra-early recovery. We now seek to assess the cost-effectiveness of tenecteplase in the MSU. METHODS: A within-trial (TASTE-A) economic analysis and a model-based long-term cost-effectiveness analysis were performed. This post hoc within-trial economic analysis utilised the patient-level data (intention to treat, ITT) prospectively collected over the trial to calculate the difference in both healthcare costs and quality-adjusted life years (QALYs, estimated from modified Rankin scale score). A Markov microsimulation model was developed to simulate the long-term costs and benefits. RESULTS: In total, there were 104 patients with ischaemic stroke randomised to tenecteplase (n = 55) or alteplase (n = 49) treatment groups, respectively in the TASTE-A trial. The ITT-based analysis showed that treatment with tenecteplase was associated with non-signficantly lower costs (A$28,903 vs A$40,150 (p = 0.056)) and greater benefits (0.171 vs 0.158 (p = 0.457)) than that for the alteplase group over the first 90 days post the index stroke. The long-term model showed that tenecteplase led to greater savings in costs (-A$18,610) and more health benefits (0.47 QALY or 0.31 LY gains). Tenecteplase-treated patients had reduced costs for rehospitalisation (-A$1464), nursing home care (-A$16,767) and nonmedical care (-A$620) per patient. CONCLUSIONS: Treatment of ischaemic stroke patients with tenecteplase appeared to be cost-effective and improve QALYs in the MSU setting based on Phase II data. The reduced total cost from tenecteplase was driven by savings from acute hospitalisation and reduce need for nursing home care.

Interdisciplinary interactions, social systems and technical infrastructure required for successful implementation of mobile stroke units: A qualitative process evaluation.

RATIONALE: Mobile stroke units (MSUs) are increasingly being implemented to provide acute stroke care in the prehospital environment, but a comprehensive implementation evaluation has not been undertaken. AIM: To identify successes and challenges in the pre- and initial operations of the first Australian MSU service from an interdisciplinary perspective. METHODS: Process evaluation of the Melbourne MSU with a mixed-methods design. Purposive sampling targeted key stakeholder groups. Online surveys (administered June-September 2019) and semistructured interviews (October-November 2019) explored experiences. Directed content analysis (raters' agreement 85%) and thematic analysis results are presented using the Interactive Sociotechnical Analysis framework. RESULTS: Participants representing executive/program operations, MSU clinicians and hospital-based clinicians completed 135 surveys and 38 interviews. Results converged, with major themes addressing successes and challenges: stakeholders, vehicle, knowledge, training/education, communication, work processes and working relationships. CONCLUSIONS: Successes and challenges of establishing a new MSU service extend beyond technical, to include operational and social aspects across prehospital and hospital environments.

Comparison of tenecteplase with alteplase for the early treatment of ischaemic stroke in the Melbourne Mobile Stroke Unit (TASTE-A): a phase 2, randomised, open-label trial.

BACKGROUND: Mobile stroke units (MSUs) equipped with a CT scanner reduce time to thrombolytic treatment and improve patient outcomes. We tested the hypothesis that tenecteplase administered in an MSU would result in superior reperfusion at hospital arrival, when compared with alteplase. METHODS: The TASTE-A trial is a phase 2, randomised, open-label trial at the Melbourne MSU and five tertiary hospitals in Melbourne, VIC, Australia. Patients (aged ≥18 years) with ischaemic stroke who were eligible for thrombolytic treatment were randomly allocated in the MSU to receive, within 4·5 h of symptom onset, either standard-of-care alteplase (0·9 mg/kg [maximum 90 mg], administered intravenously with 10% as a bolus over 1 min and 90% as an infusion over 1 h), or the investigational product tenecteplase (0·25 mg/kg [maximum 25 mg], administered as an intravenous bolus over 10 s), before being transported to hospital for ongoing care. The primary outcome was the volume of the perfusion lesion on arrival at hospital, assessed by CT-perfusion imaging. Secondary safety outcomes were modified Rankin Scale (mRS) score of 5 or 6 at 90 days, symptomatic intracerebral haemorrhage and any haemorrhage within 36 h, and death at 90 days. Assessors were masked to treatment allocation. Analysis was by intention-to-treat. The trial was registered with ClinicalTrials.gov, NCT04071613, and is completed. FINDINGS: Between June 20, 2019, and Nov 16, 2021, 104 patients were enrolled and randomly allocated to receive either tenecteplase (n=55) or alteplase (n=49). The median age of patients was 73 years (IQR 61-83), and the median NIHSS at baseline was 8 (5-14). On arrival at the hospital, the perfusion lesion volume was significantly smaller with tenecteplase (median 12 mL [IQR 3-28]) than with alteplase (35 mL [18-76]; adjusted incidence rate ratio 0·55, 95% CI 0·37-0·81; p=0·0030). At 90 days, an mRS of 5 or 6 was reported in eight (15%) patients allocated to tenecteplase and ten (20%) patients allocated to alteplase (adjusted odds ratio [aOR] 0·70, 95% CI 0·23-2·16; p=0·54). Five (9%) patients allocated to tenecteplase and five (10%) patients allocated to alteplase died from any cause at 90 days (aOR 1·12, 95% CI 0·26-4·90; p=0·88). No cases of symptomatic intracerebral haemorrhage were reported within 36 h with either treatment. Up to day 90, 13 serious adverse events were noted: five (5%) in patients treated with tenecteplase, and eight (8%) in patients treated with alteplase. INTERPRETATION: Treatment with tenecteplase on the MSU in Melbourne resulted in a superior rate of early reperfusion compared with alteplase, and no safety concerns were noted. This trial provides evidence to support the use of tenecteplase and MSUs in an optimal model of stroke care. FUNDING: Melbourne Academic Centre for Health.

Tenecteplase versus Alteplase for Stroke Thrombolysis Evaluation Trial in the Ambulance (Mobile Stroke Unit-TASTE-A): protocol for a prospective randomised, open-label, blinded endpoint, phase II superiority trial of tenecteplase versus alteplase for ischaemic stroke patients presenting within 4.5 hours of symptom onset to the mobile stroke unit.

INTRODUCTION: Mobile stroke units (MSUs) equipped with a CT scanner are increasingly being used to assess and treat stroke patients' prehospital with thrombolysis and transfer them to the most appropriate hospital for ongoing stroke care and thrombectomy when indicated. The effect of MSUs in both reducing the time to reperfusion treatment and improving patient outcomes is now established. There is now an opportunity to improve the efficacy of treatment provided by the MSU. Tenecteplase is a potent plasminogen activator, which may have benefits over the standard of care stroke lytic alteplase. Specifically, in the MSU environment tenecteplase presents practical benefits since it is given as a single bolus and does not require an infusion over an hour like alteplase. OBJECTIVE: In this trial, we seek to investigate if tenecteplase, given to patients with acute ischaemic stroke as diagnosed on the MSU, improves the rate of early reperfusion. METHODS AND ANALYSIS: TASTE-A is a prospective, randomised, open-label, blinded endpoint (PROBE) phase II trial of patients who had an ischaemic stroke assessed in an MSU within 4.5 hours of symptom onset. The primary endpoint is early reperfusion measured by the post-lysis volume of the CT perfusion lesion performed immediately after hospital arrival. ETHICS AND DISSEMINATION: The study was approved by the Royal Melbourne Hospital Human Ethics committee. The findings will be published in peer-reviewed journals, presented at academic conferences and disseminated among consumer and healthcare professional audiences. TRIAL REGISTRATION NUMBER: NCT04071613.

The Mobile Stroke Unit Nurse: An International Exploration of Their Scope of Practice, Education, and Training.

ABSTRACT: BACKGROUND: Mobile stroke units (MSUs) are ambulance-based prehospital stroke care services. Through immediate roadside assessment and onboard brain imaging, MSUs provide faster stroke management with improved patient outcomes. Mobile stroke units have enabled the development of expanded scope of practice for stroke nurses; however, there is limited published evidence about these evolving prehospital acute nursing roles. AIMS: The aim of this study was to explore the expanded scope of practice of nurses working on MSUs by identifying MSUs with onboard nurses; describing the roles and responsibilities, training, and experience of MSU nurses, through a search of the literature; and describing 2 international MSU services incorporating nurses from Memphis, Tennessee, and Melbourne, Australia. METHODS: We searched PubMed, CINAHL, and the Joanna Briggs Institute Evidence-Based Practice database using the terms "mobile stroke unit" and "nurse." Existing MSUs were identified through the PRE-hospital Stroke Treatment Organization to determine models that involved nurses. We describe 2 MSUs involving nurses: one in Memphis and one in Melbourne, led by 2 of our authors. RESULTS: Ninety articles were found describing 15 MSUs; however, staffing details were lacking, and it is unknown how many employ nurses. Nine articles described the role of the nurse, but role specifics, training, and expertise were largely undocumented. The MSU in Memphis, the only unit to be staffed exclusively by onboard nurse practitioners, is supported by a neurologist who consults via telephone. The Melbourne MSU plans to trial a nurse-led telemedicine model in the near future. CONCLUSION: We lack information on how many MSUs employ nurses, and the nurses' scope of practice, training, and expertise. Expert stroke nurse practitioners can safely perform many of the tasks undertaken by the onboard neurologist, making a nurse-led telemedicine model an effective and potentially cost-effective model that should be considered for all MSUs.

Understanding Coordinator Roles in Acute Stroke Care: A National Survey.

OBJECTIVES: Coordinators contribute to stroke care quality. Evidence on the scope of practice of coordinator roles for stroke is lacking. We aimed to survey Australian stroke coordinators and describe their responsibilities and characteristics, and compare these based on perceived competency. MATERIALS AND METHODS: Online survey of non-physician coordinators with a clinical leadership position for acute stroke in Australian hospitals. Participants were identified from the Stroke Foundation National Audit, and advertising via national associations/networks. Quantitative data were analysed descriptively; characteristics and responsibilities assessed by Benner's self-perceived competency (novice/advanced beginner/competent, proficient or expert). Inductive thematic analysis was used for open-ended responses. RESULTS: Results from 105/141 coordinators (103 hospitals, 90% female, 90% registered nurses). Two-thirds developed the role/were self-taught, with 36% using the 'stroke coordinator' title. Perceived competency varied; 22% expert, 40% proficient, and 33% competent. A variety of important clinical tasks, along with leadership/management, education and research responsibilities were described. Most frequently reported clinical responsibility was discharge planning (77%), with patient and staff education (85% and 88%), and data collection (94%) common. Compared to those reporting lesser competency, 'experts' had greater involvement in outpatient clinics (50% vs 14%) and leadership/management responsibilities (e.g. local hospital committees 77% vs 46%). 'Knowledge of evidence' and 'empowering others' were important characteristics to 'expert' coordinators. CONCLUSIONS: A contemporary understanding of important responsibilities and characteristics of acute stroke coordinators are provided. Perceived competency affected scope of practice. Structured education, training and role delineation is warranted to improve competency. Career development of stroke coordinators is urgently needed to support optimal role performance.

Mobile Stroke Units Facilitate Prehospital Management of Intracerebral Hemorrhage.

Background and Purpose: Mobile stroke units (MSUs) improve reperfusion therapy times in acute ischemic stroke (AIS). However, prehospital management options for intracerebral hemorrhage (ICH) are less established. We describe the initial Melbourne MSU experience in ICH. Methods: Consecutive patients with ICH and AIS treated by the Melbourne MSU were included. We describe demographics, proportions of patients receiving specific therapies, and bypass to comprehensive/neurosurgical centers. We also compare operational time metrics between patients with MSU-ICH and MSU-AIS. Results: During a 2-year period, the Melbourne MSU managed 49 patients with ICH, mean (SD) age 74 (12) years, median (interquartile range) National Institutes of Health Stroke Scale 17 (12­20). Intravenous antihypertensives were the commonest treatment provided (46.9%). Bypass of a primary center to a comprehensive center with neurosurgical expertise occurred in 32.7% of patients with MSU-ICH compared with 20.5% of patients with MSU-AIS. Compared with patients with MSU-AIS, patients with MSU-ICH had faster onset-to-emergency-call, and onset-to-scene-arrival times at the median and 75th percentiles. Conclusions: MSUs can facilitate ultra-early ICH diagnosis, management, and triage.

Economic evaluation of the Melbourne Mobile Stroke Unit.

BACKGROUND: The Melbourne Mobile Stroke Unit (MSU) is the first Australian service to provide prehospital acute stroke treatment, including thrombolysis and facilitated triage for endovascular thrombectomy. AIMS: To estimate the cost-effectiveness of the MSU during the first full year of operation compared with standard ambulance and hospital stroke care pathways (standard care). METHODS: The costs and benefits of the Melbourne MSU were estimated using an economic simulation model. Operational costs and service utilization data were obtained from the MSU financial and patient tracking reports. The health benefits were estimated as disability-adjusted life years (DALYs) avoided using local data on reperfusion therapy and estimates from the published literature on their effectiveness. Costs were presented in Australian dollars. The robustness of results was assessed using multivariable (model inputs varied simultaneously: 10,000 Monte Carlo iterations) and various one-way sensitivity analyses. RESULTS: In 2018, the MSU was dispatched to 1244 patients during 200 days of operation. Overall, 167 patients were diagnosed with acute ischemic stroke, and 58 received thrombolysis, endovascular thrombectomy, or both. We estimated 27.94 DALYs avoided with earlier access to endovascular thrombectomy (95% confidence interval (CI) 15.30 to 35.93) and 16.90 DALYs avoided with improvements in access to thrombolysis (95% CI 9.05 to 24.68). The MSU was estimated to cost an additional $30,982 per DALY avoided (95% CI $21,142 to $47,517) compared to standard care. CONCLUSIONS: There is evidence that the introduction of MSU is cost-effective when compared with standard care due to earlier provision of reperfusion therapies.

Melbourne Mobile Stroke Unit and Reperfusion Therapy: Greater Clinical Impact of Thrombectomy Than Thrombolysis.

Background and Purpose- Mobile stroke units (MSUs) are increasingly used worldwide to provide prehospital triage and treatment. The benefits of MSUs in giving earlier thrombolysis have been well established, but the impacts of MSUs on endovascular thrombectomy (EVT) and effect on disability avoidance are largely unknown. We aimed to determine the clinical impact and disability reduction for reperfusion therapies in the first operational year of the Melbourne MSU. Methods- Treatment time metrics for MSU patients receiving reperfusion therapy were compared with control patients presenting to metropolitan Melbourne stroke units via standard ambulance within MSU operating hours. The primary outcome was median time difference in first ambulance dispatch to treatment modeled using quantile regression analysis. Time savings were subsequently converted to disability-adjusted life years avoided using published estimates. Results- In the first 365-day operation of the Melbourne MSU, prehospital thrombolysis was administered to 100 patients (mean age, 73.8 years; 62% men). The median time savings per MSU patient, compared with the control cohort, was 26 minutes (P<0.001) for dispatch to hospital arrival and 15 minutes (P<0.001) for hospital arrival to thrombolysis. The calculated overall time saving from dispatch to thrombolysis was 42.5 minutes (95% CI, 36.0-49.0). In the same period, 41 MSU patients received EVT (mean age, 76 years; 61% men) with median dispatch-to-treatment time saving of 51 minutes ([95% CI, 30.1-71.9], P<0.001). This included a median time saving of 17 minutes ([95% CI, 7.6-26.4], P=0.001) for EVT hospital arrival to arterial puncture for MSU patients. Estimated median disability-adjusted life years saved through earlier provision of reperfusion therapies were 20.9 for thrombolysis and 24.6 for EVT. Conclusions- The Melbourne MSU substantially reduced time to reperfusion therapies, with the greatest estimated disability avoidance driven by the more powerful impact of earlier EVT. These findings highlight the benefits of prehospital notification and direct triage to EVT centers with facilitated workflow on arrival by the MSU.

Reliability of the Acutely Estimated Premorbid Modified Rankin Scale for Stroke Treatment Decision Making.

BACKGROUND: Premorbid functional status is an important factor in acute stroke treatment decision making. Determining the modified Rankin Score (mRS) accurately may be difficult due to deficits from stroke and lack of collateral information in the acute setting. Data on the reliability of the premorbid mRS in "real-world" practice outside of clinical trial or registry settings are limited. METHODS: A retrospective study at a high volume academic primary stroke center. For patients with acute ischemic stroke treated with alteplase between July 2012 and July 2016, hospital electronic records were reviewed for detailed inpatient occupational therapist (OT) assessment of premorbid functional status to determine mRS (OT-mRS). This was compared with premorbid mRS determined at acute emergency department assessment (Acute-mRS). Kappa statistic and Lin's concordance correlation coefficient was used to calculate agreement between Acute-mRS and OT-mRS. RESULTS: Among stroke patients treated with alteplase over the 4 years period, OT-mRS was available for 312 patients (79.0%), the mean age was 75.5 years (male 51.9%). 82.4%, 11.9%, and 5.8% of patients had Acute-mRS of 0-1, 2, and ≥3; while 84.9%, 8.0%, and 6.7% had OT-mRS of 0-1, 2, and ≥3, respectively. The agreement between Acute-mRS and OT-mRS was 83.3%, with κ = .64 and correlation coefficient r = .87 (95% CI .841-.896, P < .05). CONCLUSIONS: There was at least moderate agreement between Acute-mRS prior to thrombolysis and OT-mRS obtained by detailed assessment later. The number of patients with premorbid disability was small and may have positively influenced the agreement between the 2 scores.

Prehospital idarucizumab prior to intravenous thrombolysis in a mobile stroke unit.

BACKGROUND: Administration of intravenous idarucizumab to reverse dabigatran anticoagulation prior to thrombolysis for patients with acute ischemic stroke has been previously described, but not in the prehospital setting. The speed and predictability of idarucizumab reversal is well suited to prehospital treatment in a mobile stroke unit and allows patients with recent dabigatran intake to access reperfusion therapy. AIMS: To describe feasibility of prehospital idarucizumab administration prior to thrombolysis on the Melbourne mobile stroke unit. METHODS: The Melbourne mobile stroke unit is a specialized stroke ambulance servicing central metropolitan Melbourne, Australia and provides prehospital assessment, scanning and treatment with an integrated CT scanner and multidisciplinary stroke team. All cases were identified through the mobile stroke unit treatment registry since launch in November 2017. RESULTS: Of a total of n = 20 thrombolysis cases in the first 4 months of operation, three patients (15%) received intravenous idarucizumab 5 g for dabigatran reversal prior to thrombolysis. Mean time between idarucizumab administration and thrombolysis was approximately 10 minutes. Two of the three patients were shown to have large vessel occlusion on CTA in the mobile stroke unit and proceeded to endovascular thrombectomy. At 24 hours, only one patient had a small amount of asymptomatic petechial hemorrhage on follow-up imaging. All patients demonstrated substantial neurological recovery and were discharged to inpatient rehabilitation. CONCLUSIONS: Rapid treatment with prehospital administration of idarucizumab prior to thrombolysis using a mobile stroke unit is feasible and facilitates hyperacute treatment.

Acute Stroke Patients With Mild-to-Moderate Pre-existing Disability Should Be Considered for Thrombolysis Treatment.

BACKGROUND: Thrombolytic therapy in patients with pre-existing disability presenting with acute ischemic stroke (AIS) is controversial because of concerns regarding poor outcomes and futility of treatment. We hypothesized that a similar proportion of patients with and without pre-existing disability would return to their premorbid functional status following thrombolysis. METHODS: This was a retrospective study at a single high-volume academic primary stroke center. All patients with AIS treated with intravenous alteplase between January 2005 and July 2016 were included. Premorbid functional status was assessed using modified Rankin scale (mRS) and dichotomized as independent premorbid (mRS 0-1) or disabled premorbid (mRS 2-4) groups for comparison. Functional outcome was assessed by mRS at 90 days and compared between groups. RESULTS: Six hundred eighty patients independent premorbid (mean age 71.8 ± 13.1 years, 57.9% male) and 140 disabled premorbid (mean age 82.1 ± 8.7 years, 40.7% male) were included. Patients with pre-existing disability were older and had more vascular risk factors and more severe stroke on presentation (P < 0.05). A greater proportion of patients in the disabled premorbid group were dead at 90 days (35.7% versus 12.8%, P < 0.05). At 90 days, among patients with premorbid mRS 0, 1, 2, 3, and 4: 25%, 38%, 32%, 30%, and 25% of them returned to their respective premorbid mRS status. CONCLUSIONS: Irrespective of premorbid functional level, approximately one fourth to one third of thrombolyzed patients had returned to their premorbid functional levels at 90 days. Thrombolytic treatment should be considered in patients with mild-to-moderate pre-existing disability, taking into account the value placed on the chance of a return to premorbid functional status.

Ambulance Clinical Triage for Acute Stroke Treatment: Paramedic Triage Algorithm for Large Vessel Occlusion.

BACKGROUND AND PURPOSE: Clinical triage scales for prehospital recognition of large vessel occlusion (LVO) are limited by low specificity when applied by paramedics. We created the 3-step ambulance clinical triage for acute stroke treatment (ACT-FAST) as the first algorithmic LVO identification tool, designed to improve specificity by recognizing only severe clinical syndromes and optimizing paramedic usability and reliability. METHODS: The ACT-FAST algorithm consists of (1) unilateral arm drift to stretcher <10 seconds, (2) severe language deficit (if right arm is weak) or gaze deviation/hemineglect assessed by simple shoulder tap test (if left arm is weak), and (3) eligibility and stroke mimic screen. ACT-FAST examination steps were retrospectively validated, and then prospectively validated by paramedics transporting culturally and linguistically diverse patients with suspected stroke in the emergency department, for the identification of internal carotid or proximal middle cerebral artery occlusion. The diagnostic performance of the full ACT-FAST algorithm was then validated for patients accepted for thrombectomy. RESULTS: In retrospective (n=565) and prospective paramedic (n=104) validation, ACT-FAST displayed higher overall accuracy and specificity, when compared with existing LVO triage scales. Agreement of ACT-FAST between paramedics and doctors was excellent (κ=0.91; 95% confidence interval, 0.79-1.0). The full ACT-FAST algorithm (n=60) assessed by paramedics showed high overall accuracy (91.7%), sensitivity (85.7%), specificity (93.5%), and positive predictive value (80%) for recognition of endovascular-eligible LVO. CONCLUSIONS: The 3-step ACT-FAST algorithm shows higher specificity and reliability than existing scales for clinical LVO recognition, despite requiring just 2 examination steps. The inclusion of an eligibility step allowed recognition of endovascular-eligible patients with high accuracy. Using a sequential algorithmic approach eliminates scoring confusion and reduces assessment time. Future studies will test whether field application of ACT-FAST by paramedics to bypass suspected patients with LVO directly to endovascular-capable centers can reduce delays to endovascular thrombectomy.

Large Vessel Occlusion Scales Increase Delivery to Endovascular Centers Without Excessive Harm From Misclassifications.

BACKGROUND AND PURPOSE: Clinical large vessel occlusion (LVO) triage scales were developed to identify and bypass LVO to endovascular centers. However, there are concerns that scale misclassification of patients may cause excessive harm. We studied the settings where misclassifications were likely to occur and the consequences of these misclassifications in a representative stroke population. METHODS: Prospective data were collected from consecutive ambulance-initiated stroke alerts at 2 stroke centers, with patients stratified into typical (LVO with predefined severe syndrome and non-LVO without) or atypical presentations (opposite situations). Five scales (Rapid Arterial Occlusion Evaluation [RACE], Los Angeles Motor Scale [LAMS], Field Assessment Stroke Triage for Emergency Destination [FAST-ED], Prehospital Acute Stroke Severity scale [PASS], and Cincinnati Prehospital Stroke Severity Scale [CPSSS]) were derived from the baseline National Institutes of Health Stroke Scale scored by doctors and analyzed for diagnostic performance compared with imaging. RESULTS: Of a total of 565 patients, atypical presentations occurred in 31 LVO (38% of LVO) and 50 non-LVO cases (10%). Most scales correctly identified >95% of typical presentations but <20% of atypical presentations. Misclassification attributable to atypical presentations would have resulted in 4 M1/internal carotid artery occlusions, with National Institutes of Health Stroke Scale score ≥6 (5% of LVO) being missed and 9 non-LVO infarcts (5%) bypassing the nearest thrombolysis center. CONCLUSIONS: Atypical presentations accounted for the bulk of scale misclassifications, but the majority of these misclassifications were not detrimental, and use of LVO scales would significantly increase timely delivery to endovascular centers, with only a small proportion of non-LVO infarcts bypassing the nearest thrombolysis center. Our findings, however, would require paramedics to score as accurately as doctors, and this translation is made difficult by weaknesses in current scales that need to be addressed before widespread adoption.

Utility of Computed Tomographic Perfusion in Thrombolysis for Minor Stroke.

BACKGROUND AND PURPOSE: The use of thrombolysis in acute minor ischemic stroke (MIS) remains controversial. We sought to determine the safety and efficacy of intravenous tissue-type plasminogen activator (IV-tPA) in acute MIS patients with demonstrable penumbra on computed tomographic perfusion study. METHODS: Consecutive MIS patients with National Institutes of Health Stroke Scale ≤3 were identified from a prospective single tertiary-center database over a 4.5-year period (2011-2015). Cases with demonstrable penumbra were analyzed according to treatment received: IV-tPA versus standard stroke-unit care without thrombolysis. RESULTS: Seventy-three patients of 195 acute MIS admissions had a demonstrable penumbra (34 IV-tPA versus 39 standard stroke-unit care). Overall median National Institutes of Health Stroke Scale and premorbid modified Rankin Scale were 2 and 0, respectively. Median age was 73.2 (interquartile range, 67.3-82.8) years. There were no differences in baseline demographics, risk factors, stroke localization and cause, rates of vascular occlusion (38.2% versus 38.5%; P=1.000), or mean penumbral volume (41.3 versus 25.1 mL; P=0.150; IV-tPA versus standard stroke-unit care) between groups. There were no symptomatic intracerebral hemorrhages in either group. Patients treated with IV-tPA were more likely to have an excellent functional outcome at discharge (88.2% versus 53.9%; P=0.002) and 90 days (91.2% versus 71.8%; P=0.042). Ordinal analysis demonstrated a favorable shift in modified Rankin Scale with IV-tPA both at discharge (odds ratio, 5.23; 95% confidence interval, 1.83-12.20) and 90 days (odds ratio, 4.35; 95% confidence interval, 1.77-11.36). CONCLUSIONS: In selected MIS patients with demonstrable penumbra on computed tomographic perfusion, IV-tPA is safe and associated with significant improvement in functional outcome at discharge and 90 days.

Validation of the DRAGON score in 12 stroke centers in anterior and posterior circulation.

BACKGROUND AND PURPOSE: The DRAGON score predicts functional outcome in the hyperacute phase of intravenous thrombolysis treatment of ischemic stroke patients. We aimed to validate the score in a large multicenter cohort in anterior and posterior circulation. METHODS: Prospectively collected data of consecutive ischemic stroke patients who received intravenous thrombolysis in 12 stroke centers were merged (n=5471). We excluded patients lacking data necessary to calculate the score and patients with missing 3-month modified Rankin scale scores. The final cohort comprised 4519 eligible patients. We assessed the performance of the DRAGON score with area under the receiver operating characteristic curve in the whole cohort for both good (modified Rankin scale score, 0-2) and miserable (modified Rankin scale score, 5-6) outcomes. RESULTS: Area under the receiver operating characteristic curve was 0.84 (0.82-0.85) for miserable outcome and 0.82 (0.80-0.83) for good outcome. Proportions of patients with good outcome were 96%, 93%, 78%, and 0% for 0 to 1, 2, 3, and 8 to 10 score points, respectively. Proportions of patients with miserable outcome were 0%, 2%, 4%, 89%, and 97% for 0 to 1, 2, 3, 8, and 9 to 10 points, respectively. When tested separately for anterior and posterior circulation, there was no difference in performance (P=0.55); areas under the receiver operating characteristic curve were 0.84 (0.83-0.86) and 0.82 (0.78-0.87), respectively. No sex-related difference in performance was observed (P=0.25). CONCLUSIONS: The DRAGON score showed very good performance in the large merged cohort in both anterior and posterior circulation strokes. The DRAGON score provides rapid estimation of patient prognosis and supports clinical decision-making in the hyperacute phase of stroke care (eg, when invasive add-on strategies are considered).

Induced hypothermia after out-of-hospital cardiac arrest: one hospital's experience.

OBJECTIVE: Induced mild hypothermia has been shown to reduce in-hospital mortality and to improve neurological outcome in patients who remain comatose after out-ofhospital cardiac arrest (OHCA). We conducted a retrospective audit to assess whether induced hypothermia had been successfully incorporated into routine care at our hospital, and whether this improved patient outcomes. DESIGN AND SETTING: Retrospective audit of patients admitted to a Level III intensive care unit, Melbourne, Victoria, between 2001 and 2007. Patients treated with therapeutic hypothermia (introduced in 2004) were compared with those who did not receive this therapy. PARTICIPANTS: Patients admitted to the ICU comatose after OHCA with a presumed cardiac cause. INTERVENTIONS: Induction of mild hypothermia by rapid infusion of cold intravenous fluids. MAIN OUTCOME MEASURES: Hospital survival and neurological outcome at hospital discharge; time taken for core temperature to reach the target range (33 degrees +/-0.5 degrees C) and time temperature was maintained, determined from patient ICU records. RESULTS: 123 patients were admitted comatose after OHCA with a presumed cardiac cause: 75 were admitted after induced hypothermia was introduced into routine care and received this treatment; and 48 admitted earlier did not receive the treatment. For patients with the initial rhythm of ventricular fibrillation (VF) or unstable ventricular tachycardia (uVT), treatment with induced hypothermia was associated with a higher hospital survival rate (P=0.03; odds ratio [OR], 2.51; 95% CI, 1.06-5.95) and better neurological outcome (P=0.02; OR, 2.85; 95% CI, 1.19-6.86). In 90% of patients treated with induced hypothermia, core temperature reached the target range within 6 hours of hospital presentation; mean duration of in-hospital cooling was 25.5 hours (SD, 2.9 hours). CONCLUSIONS: We found that induced hypothermia can be incorporated into routine care of patients admitted to an ICU after OHCA. For patients with an initial rhythm of VF or uVT, this seems to have significantly improved hospital survival and neurological outcome. We also found that rapid infusion of cold intravenous fluids was effective for inducing hypothermia.