- The recommendations in Section 3 cover the management of potential patients with stroke from the time of first contact with the local emergency medical services (EMS) to transfer of care to the hospital and transfer between healthcare facilities by EMS.
- These recommendations are directed to EMS personnel and those individuals who support EMS, including communications officers and dispatchers. They also apply to other first responders such as emergency medical responders and primary care paramedics who have been trained to screen for stroke and manage potential patients with stroke during transfer. These recommendations are intended to be translated into practice by the entire breadth of out-of-hospital healthcare providers within the defined scope of practice of each.
Definitions and Context
Approximately two-thirds of all patients who seek acute care for stroke arrive at the emergency department by ambulance. Local variations should be taken into consideration for prehospital time (e.g., remote locations with poor road access).
The three timelines below have been established to describe EMS in Canada for patients with stroke who may be eligible for acute ischemic stroke therapy, including intravenous thrombolysis and endovascular thrombectomy (EVT). The probability of disability-free survival decreases as the time from symptom onset to treatment increases. Therefore, all phases of patient care should aim for the shortest possible process and treatment times.
Prehospital phase (Timeline 1): Starts with symptom onset and ends with hospital arrival and includes on-scene management and transport time. Patients with ischemic stroke who can arrive at hospital within a 4.5 hour time window from witnessed stroke symptom onset or last known well and be treated as soon as possible may be eligible to receive medical treatment with intravenous thrombolysis; thrombolysis may be offered alone or in combination with endovascular intervention (e.g., thrombectomy, other endovascular procedures such as stenting) which has a 6-hour time window for most patients. Highly selected patients may be eligible for EVT up to 24 hours from stroke symptom onset or last known well. Refer to Section 4 Emergency Department Evaluation and Management of Patients with Transient Ischemic Attack and Acute Stroke for more information.
Emergency department phase (Timeline 2): Starts with hospital arrival and ends with disposition time from the emergency department. People with stroke may transition from the emergency department to various settings: admission (ideally to a stroke unit) for inpatient care, transfer to another healthcare facility, or discharge to the community (usually place of residence). Refer to Section 4 Emergency Department Evaluation and Management of Patients with Transient Ischemic Attack and Acute Stroke for more information.
Interhospital transfer time (Timeline 3): Applies to patients with stroke who require transfer from one hospital to another to receive more advanced stroke care. The delay for patients who first arrive at an emergency department that has limited acute stroke services and who then requires transfer can be an important factor in determining outcomes. The recommendations in this section suggest that this time be as short as possible, and EMS plays a key role in timing and the transfer process.
Recommendations and/or Clinical Considerations
Out-of-hospital patient management should be organized to achieve the rapid assessment and treatment of patients with suspected stroke, including rapid recognition of potential stroke symptoms, EMS mobilization, and transport to an acute care hospital with acute stroke management capability [Strong recommendation; Moderate quality of evidence].
3.1 Access to Emergency Medical Services (EMS)
- A person experiencing the signs or symptoms of stroke, or any witness, should immediately contact EMS by calling 9-1-1 or the local emergency number [Strong recommendation; Moderate quality of evidence]. Refer to Section 1 for additional information.
- EMS communications centre: All regions in Canada should implement a dispatch process through their EMS communications centres to rapidly recognize signs or symptoms of stroke (e.g., FAST: Face, Arms, Speech, Time), prioritize response to the scene, and transport the patient to a hospital capable of providing acute services for rapid diagnosis and time-sensitive treatment of stroke (such as neuroimaging, and acute thrombolysis) [Strong recommendation; Low quality of evidence].
- After dispatching the ambulance, it is recommended that EMS communications centre personnel provide pre-arrival instructions to the person reporting the stroke (e.g., unlock door, move pets, determine stroke symptom onset time, determine current medications), in order to expedite, optimize, and improve safety for prehospital care [Conditional recommendation; Low quality of evidence]. Note: If the person experiencing the signs of stroke is the one to contact EMS, they may not be able to comply with these requests.
3.2 Paramedic On-Scene Management
Note: The on-scene goal is to recognize and mobilize. It is of the utmost importance to rapidly and safely transport suspected patients with stroke, as on-scene management for patients with stroke is limited.
- To minimize time to acute treatment for thrombolysis or EVT, EMS personnel should use a validated acute stroke out-of-hospital diagnostic screening tool that includes the components of FAST [Strong recommendation; Moderate quality of evidence].
- To optimize access to EVT, patients who demonstrate FAST signs of stroke should then undergo a valid secondary screen to assess stroke severity, which may be used to identify candidates for direct transport to an EVT capable centre where possible [Strong recommendation; Moderate quality of evidence]. Note: The purpose of the second screen is to look for possible EVT candidates, such as people exhibiting signs of cortical dysfunction (e.g., aphasia, visual changes, neglect).
- Screening for potential stroke and likelihood of large vessel occlusion (LVO) should be done early in the on-scene assessment. If the stroke screen is positive, all on-scene actions from that point should be focused on moving to the ambulance and beginning transport [Strong recommendation; Moderate quality of evidence].
Refer to Appendix 3, Canadian Stroke Best Practices Table 3A of Standardized Acute Prehospital Stroke Screening Tools; Table 3B Additional Tools and Table 3C Prehospital Stroke Screening Scales to Identify Large Vessel Occlusion (LVO).
- Treatments that are not immediately required could be undertaken while the patient is enroute to the hospital or after hospital arrival [Strong recommendation, Low quality of evidence].
- EMS personnel should obtain information from the patient, family members or other witnesses about the suspected stroke event, including presenting symptoms, time of onset or time of symptom recognition and time last known well, sequence of events, co-morbid conditions, current medications (especially anticoagulants), and any formal or informal advance directives that may influence care by EMS and in the emergency department [Strong recommendation; Moderate quality of evidence]. Refer to Box 3A for additional information.
- On-scene time with any patient with suspected stroke should be as short as possible; ideally a median time of <20 minutes [Strong recommendation; Low quality of evidence].
- Initial assessment provided by paramedics should include capillary blood glucose measurement [Strong recommendation; Moderate quality of evidence].
- Ideally capillary blood glucose measurement should be done on-scene to inform transport decisions [Conditional recommendation; Low quality of evidence].
- Prior to transport, on-scene EMS personnel should provide instructions to the patients’ family, including recommending that the family member or other decision-maker accompany the patient to hospital or be accessible by phone for decision-making; confirming time last known well; and providing information about existing health conditions, current medications, and other information as needed [Strong recommendation; Low quality of evidence].
3.3 Transport of Patients with Suspected Stroke
- Direct transport protocols should be in place to facilitate the transfer of patients with suspected acute stroke who are potentially eligible for thrombolytic and/or EVT to the most appropriate acute care hospital capable of providing services for the diagnosis and treatment of acute stroke [Strong recommendation; Moderate quality of evidence].
- Direct transport protocols should take into account the medical stability of the patient, last known well time, severity of the stroke, and any regional factors [Strong recommendation; Moderate quality of evidence]. Refer to Box 3B for additional information.
- Patients with suspected stroke should be triaged by EMS as Canadian Triage Acuity Scale (CTAS) Level 2 in most cases and as a CTAS Level 1 for patients with compromised airway, breathing, or cardiovascular function [Strong recommendation; Moderate quality of evidence].
- Pre-notification: While enroute to the receiving hospital that provides acute stroke services, EMS should notify the emergency department of the incoming suspected acute stroke patient and provide sufficient details such that a "Code Stroke" can be activated at that time [Strong recommendation; Moderate quality of evidence]. Refer to Box 3A for additional information.
- Patients with suspected stroke who are considered ineligible for intravenous thrombolytic therapy or EVT (e.g., they are outside the time window) should still be transported immediately to the closest hospital capable of providing acute stroke diagnosis and management services, where assessment and determination can be made for transport to a higher level of care as appropriate [Strong recommendation; High quality of evidence].
3.4 Hospital Arrival and EMS Handover to Emergency Department (ED) Staff
- Transfer of care from paramedics to receiving hospital personnel should occur with minimal delay and patients with suspected acute stroke who are potentially eligible for thrombolytic therapy or EVT should receive highest priority in the emergency department triage queue [Strong recommendation; Moderate quality of evidence]. Refer to Section 4.1 for more information.
- At hospital arrival, paramedics should provide the receiving hospital with verbal and written information related to the patient’s stroke onset time, last known well time, presenting symptoms, and medications, to facilitate rapid assessment and decision-making [Strong recommendation; Low quality of evidence]. Refer to Box 3A for additional information.
- The standard window for intravenous thrombolysis is 4.5 hours and the standard time window for EVT is 6 hours. However, patients may be considered eligible beyond these windows based on clinical factors and neuroimaging findings.
- Direct transport in many regions may take one of two potential pathways based on local or regional considerations:
- Patients who may be eligible for intravenous thrombolysis may be directed to the closest centre, which may be a primary/advanced stroke centre or comprehensive stroke centre.
- Patients who are likely candidates for EVT may be directed to (1) an EVT-enabled comprehensive stroke centre OR (2) a primary centre to rapidly receive intravenous thrombolysis and then be considered for transport to an EVT-enabled comprehensive stroke centre.
- On-scene time is an important variable that EMS professionals can control and needs to be monitored closely. Time lost due to inefficient on-scene care cannot be made up during subsequent transport to hospital, regardless of the use of lights and sirens.
- Patients should be transported by the method that allows the shortest transport time. In the event that a ground EMS response may cause significant delay in the patient transport, air transport should be considered where available.
- Pre-notification contact with the receiving emergency department should be initiated as soon as possible; where possible, the paramedics and receiving emergency department physician or stroke team member should communicate while enroute.
- For EVT-eligible patients, processes and or algorithms should be put in place that will easily enable a discussion to arrange for the patient to be transferred to the EVT-enabled comprehensive stroke centre in a timely manner. A three-way conference call among the referring clinician (paramedic or emergency department physician at a primary/advanced stroke centre), the receiving physician at the EVT-enabled centre, and the ambulance service involved in patient transport should support decision-making regarding direct to EVT centre or closer centre for initial imaging and assessment.
- Mobile Stroke Units: The Canadian Stroke Best Practices writing group is currently unable to make a recommendation about mobile stroke units as published data on their use in the context of Canadian geography and health system organization are lacking. The group encourages further research into mobile stroke units in Canada as high-quality studies from other jurisdictions suggest that the use of these specialized units is associated with a reduced time to thrombolysis, an increased proportion of patients receiving thrombolysis, and better functional outcomes at 90 days.
Acute stroke is a medical emergency and optimizing out-of-hospital (prehospital) care improves patient outcomes. EMS plays a critical role in prehospital assessment and management of patients with suspected stroke. Acute interventions such as thrombolytic therapy and EVT are time sensitive; therefore, strategies to reduce delays such as re-directing ambulances to stroke centres and prenotification by EMS staff can help identify patients with more severe strokes who may be eligible for such treatments.
Intravenous thrombolytic therapy should be administered within a 4.5-hour treatment window, while EVT is best performed within 6 hours from stroke onset. In selected patients, EVT can be used in combination with intravenous thrombolysis (given within 4.5 hours of symptom onset), with numbers needed to treat reported as low as 3 – 4. EVT is also beneficial as a sole treatment for those persons who are ineligible for intravenous thrombolysis. In addition, a small group of patients may still benefit from EVT up to 24 hours from symptom onset when selected by neurovascular imaging in the context of a coordinated stroke system that includes access to experts in stroke and neurointerventional care.
People with lived experience stressed the importance of quick EMS arrival, as well as transport to the appropriate hospital to receive care. They emphasized the importance of calling 911 (or the local emergency number) when stroke signs are present, and not driving yourself or a loved one to the hospital.
To ensure people experiencing a stroke receive timely stroke assessments, interventions and management, interdisciplinary teams need to have the infrastructure and resources required. These may include the following components established at a systems level.
- EMS personnel training in stroke recognition (signs and symptoms including FAST mnemonic), rapid assessment (including severity), management and transport requirements in the prehospital phase of care for the geographic region being serviced.
- Ongoing paramedic education on the use of validated prehospital stroke screening protocols and tools and the ability to incorporate such protocols and tools into all prehospital assessments of patients with suspected stroke. (The CSBPR include assessment tools and educational materials, developed in collaboration with EMS leaders, for implementation across Canada.)
- Ambulance services in all parts of Canada with direct transport protocols and agreements for bypass or redirect between EMS providers and regional health authorities and/or receiving hospitals.
- EMS able to provide coordinated seamless transport (land, water, and air) and care for patients with acute stroke.
- Communication systems such as virtual stroke care (telestroke) to support timely access to specialized stroke service consultations.
- Protocols and agreements to support the transfer of patients with disabling stroke to hospitals that provide advanced acute stroke treatments including EVT, regardless of geographic location.
- In each region that has adult and pediatric acute stroke services, development of criteria and processes regarding whether to transport of children with suspected stroke to pediatric or adult stroke centres. The criteria should be based on symptoms and age and agreed upon by the adult and pediatric centres, and EMS.
- Development of processes and pathways for EMS to support decision-making regarding transportation models for patients with suspected stroke (e.g., directly to comprehensive stroke centres that have EVT services or initial imaging and care at primary stroke centres).
- Proportion of patients with stroke (or suspected stroke) arriving in the emergency department who were transported by EMS.
- Time from initial call received by emergency dispatch centre to EMS arrival on scene.
- Time from EMS arrival on scene to arrival at the receiving emergency department (ideally at a stroke-enabled hospital capable of providing intravenous thrombolysis).
- Time from initial call received by emergency dispatch centre to patient arrival at an emergency department that provides stroke services.
- Proportion of acute patients with stroke transported by EMS to a stroke-enabled hospital (i.e., designated acute stroke treatment centre) as first hospital destination. Performance target is ≥90%.
- Percent of EMS transports of patients with suspected stroke which the receiving hospital received notification enroute (pre-notification) of an incoming acute stroke patient.
- Proportion of EMS calls where out-of-hospital time is <3.5 hours from stroke symptom onset or time last known well to arrival at the emergency department. Performance target is ≥75%.
Patient-oriented outcome and experience indicators:
- Proportion of potential patients with stroke transported by EMS who received a final diagnosis of stroke or transient ischemic attack in the emergency department or at hospital discharge.
- Proportion of respondents with a stroke diagnosis who report experiencing culturally safe and appropriate care.
- Emergency department records and administrative databases track patients with stroke who arrive by ambulance (land, air, or water) as a standard data element.
- An appropriate/acceptable “over-triage” rate should be <15% (i.e., false positive stroke determinations). (Indicator 9).
- Refer to the Quality of Stroke Care in Canada Key Quality Indicators and Stroke Case Definitions 7th Edition for additional measures related to hospital bypass and pre-notification
Resources and tools listed below that are external to Heart & Stroke and the Canadian Stroke Best Practice Recommendations may be useful resources for stroke care. However, their inclusion is not an actual or implied endorsement by the Canadian Stroke Best Practices team or Heart & Stroke. The reader is encouraged to review these resources and tools critically and implement them into practice at their discretion.
Healthcare Provider Information
- Canadian Stroke Best Practice Recommendations Acute Stroke Management Module: Appendix 3: Table 3A of Standardized Acute Prehospital Stroke Screening Tools; Table 3B Additional Tools and Table 3C Prehospital Stroke Screening Scales to Identify Large Vessel Occlusion (LVO)
- Heart & Stroke: Signs of Stroke
- Heart & Stroke: FAST Signs of Stroke
- Canadian Triage Acuity Scale for adults (CTAS) and Pediatric Scale (P-CTAS)
- Stroke Engine
Information for people with lived experience of stroke, including family, friends and caregivers
Patients arriving to hospital using EMS following a stroke experience fewer delays in receiving appropriate diagnostic tests such as brain imaging, and are more likely to receive revascularization treatments, if eligible. For example, the odds of a patient receiving treatment with intravenous thrombolysis following transport to hospital by EMS increased by 52% in a cohort of 2,600 patients with a final diagnosis of ischemic stroke (Nielsen et al., 2020). Additionally, hospital pre-notification by EMS staff can significantly decrease the door-to-physician, door-to-CT scan times, and door-to-needle time (Abboud et al., 2016; Hsieh et al., 2016; Kim et al., 2016; McKinney et al., 2013; Lin et al., 2012) and increase the proportion of patients who receive intravenous thrombolysis (Nielsen et al., 2020).
In a US study based on registry data (Patel et al., 2011), of 13,894 patients who whose discharge diagnosis was stroke, patients arriving by EMS with hospital prenotification were more likely to have brain imaging completed within 25 minutes (RR= 3.0, 95% CI 2.1-4.1) and to have the results interpreted within 45 minutes (RR= 2.7, 95% CI 2.3-3.3), compared to arriving by private transport. Patients eligible for t-PA were also more likely to receive brain imaging if arriving by EMS with pre-notification (RR=1.5, 95% CI 1.1-1.9). In contrast to these findings, a cluster randomized trial (PASTA, Price et al., 2020) randomized paramedics to the PASTA pathway, which included structured prehospital information collection, prompted pre-notification, structured handover of information in hospital, and assistance with simple tasks during the initial hospital assessment or to standard care reflecting national guidelines. During the study period, 1,214 patients with confirmed stroke, last known to be well within the previous four hours, were attended to by 597 paramedics. Among patients with ischemic stroke, there was no significant difference between groups in the proportion of patients who received thrombolysis (49.7% [PASTA] vs. 52.6% [standard care], adjusted OR=0.84, 95% CI 0.60-1.17). Paramedics in the PASTA group took an average of 13.4 minutes longer to clear a care episode.
To rule in stroke as a potential cause for the patient’s symptoms, EMS personnel should first use a validated acute stroke out-of-hospital diagnostic screening tool, such as FAST. The accuracy of such scales was assessed in a recent Cochrane review. Zhelev et al. (2019) evaluated the test accuracy of several stroke recognition scales (e.g., Recognition of Stroke in the Emergency Room [ROSIER], Los Angeles Prehospital Stroke Scale [LAPSS], Ontario Prehospital Stroke Screening Tool [OPSST], Medic Prehospital Assessment for Code Stroke [MedPACS], and PreHospital Ambulance Stroke Test [PreHAST]) intended for use in a prehospital (n=17) or emergency room (n=6) setting, using data from 23 primary studies. The scales assessed in a prehospital setting in these studies included the CPSS (n=9), LAPSS (n=5), FAST (n=3), and MASS (n=3). Due to high unexplained between-study heterogeneity, and the high risk of bias in most of the studies assessing the CPSS scale, the results were not pooled. Within the 11 individual studies, sensitivity ranged from 0.44 to 0.95 and specificity from 0.21 to 0.79. For LAPSS, summary statistics were pooled. Sensitivity was 0.83 (95% CI 0.75 to 0.89) and summary specificity was 0.93 (95% CI 0.88 to 0.96). For FAST and MASS, within individual studies, sensitivity ranged from 0.64 to 0.97 and 0.74 to 0.90, respectively; specificity ranged from 0.13 to 0.92 and 0.67 to 0.86, respectively.
Endovascular revascularization techniques are now more widely available, several on-scene screening tools to identify patients with suspected LVO, designed for use by EMS technicians, have emerged. Most of these scales were derived from 3 to 6 components of the National Institutes of Health Stroke scale. Examples of these scales include Face, Arm, Speech, Time—Vision Aphasia Neglect (FAST VAN, Wasyliw et al., 2022), Field Assessment of Critical Stroke by Emergency Services for Acute Delivery (FACE2AD, Okuno et al., 2020), Field Assessment Stroke Triage for Emergency Destination (FAST-ED, Lima et al., 2016), Vision, Aphasia, and Neglect (VAN, Taleb et al., 2016), the Prehospital Acute Stroke Severity Scale (PASS, Hastrup et al., 2016), Cincinnati Prehospital Stroke Severity Scale (CPSSS, Katz et al., 2015), and The Los Angeles Motor Scale (LAMS, Nazliel et al., 2008). The sensitivities and specificities associated with these scales range from 61% to 100% and 40% to 92%, respectively. Scales were developed using data from patients with both (later confirmed) ischemic stroke and suspected stroke. Unfortunately, the performance of these scales is not ideal. Smith et al. (2018) included the results from 36 studies evaluating the accuracy of LVO prediction scales in patients with suspected stroke or presumed acute ischemic stroke in prehospital or emergency department settings. The authors concluded that no scale had both high sensitivity and specificity to determine the presence vs. absence of LVO, and that in clinical practice that the probability of LVO given a negative test could still be ≥10%.
Direct transport by EMS to a hospital that has on-site expertise in the provision of recalculation procedures increases the chance that eligible patients will receive these treatments. In the RACECAT trial (De la Ossa et al., 2022), 1,401 patients with suspected acute LVO identified by EMS in the field were randomized to transport to 6 thrombectomy-capable centres or 22 local stroke centres. Prenotification criteria for the EMS coordination centre were established to provide high sensitivity in identifying potential candidates. Compared with patients first transported to local stroke centres, patients with confirmed ischemic stroke or TIA directly transported to thrombectomy-capable centres were less likely to receive treatment with intravenous thrombolysis (47.5% vs. 60.4%, OR= 0.59, 95% CI, 0.45-0.76) but were more likely to receive thrombectomy (48.8% vs. 39.4%, OR=1.46, 95% CI 1.13-1.89). A systematic review (Mohamed et al., 2021) included the results from 19 studies examining a mothership model with a drip and ship model. Compared with patients with suspected LVO who were transported directly to a thrombectomy-capable hospital, those who were transported to the closest hospital, received intravenous thrombolysis, and were then transferred to a thrombectomy capable hospital had lower odds of a good functional outcome (mRS 0-2) at 90 days (OR=0.74, 95% CI 0.65-0.84). Similar findings were reported in another systematic review (Ismail et al., 2019), which included the results of 8 studies. Patients who underwent thrombectomy after direct transport to a comprehensive stroke centre were more likely to have a better outcome at 90 days.
The use of mobile stroke units (MSUs), which are ambulances equipped with specialized equipment such as on-site laboratories and CT scanners and staffed with additional personnel with stroke expertise, are now appearing in some large, urban cities. A recent systematic review (Turc et al., 2022) included the results of 14 controlled studies. Studies compared MSU deployment with usual care for prehospital management of acute ischemic stroke, within a 6-hour window of symptom onset. In adjusted analysis, the pooled odds of the primary outcome (mRS score of 0-2 at 90 days) were significantly higher in the MSU group (OR=1.64, 95% CI 1.27-2.13). The odds of treatment with intravenous thrombolysis were significantly higher in the MSU group (unadjusted OR= 1.83, 95% CI 1.58-2.12), as were the odds of treatment with intravenous thrombolysis within 60 minutes (unadjusted OR= 7.71, 95% CI 4.17-14.25). The results from two large trials (n=1,500) of MSUs were published in 2021. In the BEST-MSU trial (Grotta et al., 2021), MSU use was associated with a significantly increased number of t-PA eligible patients receiving the treatment, reduced time to t-PA administration, and a significantly higher utility-weighted mRS (UW-mRS) score at 90 days (the primary outcome) compared with weeks when the MSU was not deployed. Similar trends were reported in the B_PROUD Study (Ebinger et al., 2021) whereby significantly more patients in the MSU group received treatment with t-PA compared with conventional EMS, and t-PA process times were significantly shorter. Median time from dispatch to imaging was 45 vs. 60 minutes (p<0.001), and the median time from dispatch to t-PA was 50 vs. 70 minutes (p<0.001). The distribution of mRS scores also favoured the MSU group (adj common OR=0.71, 95% CI 0.58 to 0.86).
Sex & Gender Considerations
While the results from some studies indicate that women tend to utilize EMS more than men, the finding is not consistent, and reasons for the potential differences are unclear (Bushnell et al. 2018). In a retrospective study including 463,310 adult patients (Kapoor et al. 2020), ambulance utilization and time to hospital presentation across sex and age groups were examined. Older women (≥45 years) were more likely to arrive by ambulance compared with older men (68.4% vs. 63.9%; p < 0.001). There were no sex differences between younger men vs. women. Older women with ischemic stroke were significantly more likely to arrive by ambulance. Older women arrived at hospital sooner than older men (6.6 vs. 6.9 hours, p < 0.0001), while younger women arrived significantly later than younger men (9.2 vs. 7.5 hours, p = 0.004). Using data from 47,209 participants of the Austrian Stroke Registry, women were less likely to arrive at hospital via private transport (age-adjusted OR= 0.94, 95% CI 0.89–0.99) (Gattringer et al. 2014). Women may also experience greater prehospital delays and longer door-to-imaging times (Pacheco et al. 2021).