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EMS Management of Acute Stroke Patients

5th Edition
2015 UPDATE
June 2015

The Canadian Stroke Best Practice Recommendations for Hyperacute Stroke Care, 5th Edition (2015) is published in the International Journal of Stroke (IJS) and available freely online. To access the specific recommendations for EMS Management of Acute Stroke Patients and all other sections of the Hyperacute Stroke Care recommendations, please click on this URL which will take you to the recommendations online in the IJS: http://onlinelibrary.wiley.com/doi/10.1111/ijs.12551/full

For the French version of these recommendations, open the appendix at this link :  http://onlinelibrary.wiley.com/store/10.1111/ijs.12551/asset/supinfo/ijs12551-sup-0001-si.zip?v=1&s=cdf3d494242426450aaa522f104ace17857f037a

All other supporting information, including performance measures, implementation resources, evidence summaries and references, remain available through www.strokebestpractices.ca, and not through the IJS.  Please click on the appropriate sections on our website below for this additional content.

Rationale

Hyperacute stroke is a medical emergency and optimizing out-of-hospital care improves patient outcomes. Emergency medical services play a critical role in out-of-hospital (prehospital) assessment and management of suspected stroke patients. Acute interventions such as thrombolytic therapy are time-sensitive and therefore strategies such as re-directing ambulances to stroke centres to facilitate earlier assessment, diagnosis, and treatment may result in better outcomes.

New therapies have also emerged (endovascular treatments or endovascular therapy) with very strong, high-quality evidence that demonstrates patients with disabling ischemic stroke who meet imaging criteria have significant benefits from receiving these therapies. The bulk of the evidence supports endovascular therapy within 6 hours from stroke symptom onset as a highly beneficial treatment in combination with intravenous thrombolysis (given within 4.5 hours of symptom onset). Endovascular therapy is also beneficial as a sole treatment among those ineligible for intravenous thrombolysis. In addition, a minority of patients may still benefit from endovascular therapy up to 12 hours from symptom onset when selected by neurovascular imaging in the context of a coordinated stroke system, including experts in stroke and neurointerventional care.

System Implications

  • Programs to train all emergency medical services personnel regarding stroke recognition, assessment, management, and transport requirements in the pre-hospital phase of care.
  • Paramedic education that includes the recognition of the signs and symptoms of acute stroke, including knowledge of the FAST mnemonic, and the need to provide rapid and appropriate out-of-hospital assessment.
  • Ongoing paramedic education on the use of validated pre-hospital stroke screening protocols and tools and the ability to incorporate such protocols and tools into all pre-hospital assessments of suspected stroke patients. The Canadian Stroke Best Practice Recommendations include assessment tools and educational materials in collaboration with emergency medical service leaders for implementation across Canada.
  • Direct transport protocols and agreements (for bypass or redirect) between emergency medical service providers and regional health authorities and/or receiving hospitals.
  • Emergency medical services able to provide coordinated seamless transport (land, water, and air) and care for acute stroke patients.
  • Communication systems such as telemedicine to support access to specialized stroke services.
  • Protocols and agreements in place to support the transfer of patients with disabling stroke to hospitals that provide advanced acute stroke treatments including endovascular therapy, regardless of geographic location.
  • Development of processes in each region that has both adult and paediatric acute services with criteria for transporting children with suspected stroke – based on symptoms and age – to paediatric versus adult stroke centres. These criteria should be agreed upon by both adult and paediatric centres, and EMS.
Performance Measures

  1. Time from initial call received by emergency dispatch centre to patient arrival at an emergency department that provides stroke services.
  2. Percentage of (suspected) stroke patients arriving in the ED who were transported by EMS.
  3. Proportion of acute stroke patients transported by EMS to the correct hospital (i.e. designated hyperacute stroke treatment centre) as first hospital destination. Target greater than or equal to 90%.
  4. Proportion of acute stroke patients presenting to the ED as a result of EMS transport versus "walk in". Target greater or equal than 90%.
  5. Time from initial call received by emergency dispatch centre to EMS arrival on scene.
  6. Time from EMS arrival on scene to arrival at the receiving ED (ideally at a stroke centre providing acute stroke services).
  7. Percent of EMS transports of ischemic stroke patients with symptoms less than 4.5 hours, and less than 6 hours, for which the receiving hospital received notification en route (pre-notification) of an incoming acute stroke patient.
  8. Percentage of EMS calls where out-of-hospital time is less than 3.5 hours from symptom onset time (or time last known well) to arrival at the ED (performance target is greater or equal to 75 percent).
  9. Percentage of potential stroke patients transported by EMS who received a final diagnosis of stroke or transient ischemic attack in the ED or at hospital discharge.
  10. For paediatric stroke patients, the time from initial presentation to any entry point in the healthcare system (such as primary care or pediatrician office, emergency department) with symptoms of stroke to a confirmed diagnosis of stroke is received.

Measurement Notes

  • Emergency department records and administrative databases track stroke patients who arrive by ambulance (land, air, or water) as a standard data element.
  • “Appropriate” emergency department refers to an emergency department that has access to a CT scanner in the facility, provides access to acute thrombolysis, and has medical personnel with stroke expertise available for emergent consult.
  • “Appropriate” emergency department may also refer to emergency departments in stroke centres that have access to endovascular therapy.
  • An appropriate/acceptable ‘over-triage’ rate should be less than 15% - i.e., false positive stroke determinations.
  • Refer to the Canadian Stroke Performance Measurement Manual for additional measures related to hospital bypass and pre-notification.
Implementation Resources and Knowledge Transfer Tools

Health Care Provider Information

Patient Information

Summary of the Evidence, Evidence Tables and References

Evidence Table 2 EMS Management of Acute Stroke

Patients arriving to hospital using EMS (emergency medical services) following a stroke experience fewer delays in receiving appropriate diagnostic tests (e.g. brain imaging) and are more likely to receive t-PA if eligible. Patients are also more likely to received timely transportation and care when pre-notification systems are adopted by EMS dispatchers. Hospital pre-notification typically involves informing emergency department physicians and other relevant personnel (blood and EKG technicians, radiologists and pharmacologists) of the arrival of a potential stroke patient. In a study based on registry data (Patel et al. 2011), of 13,894 patients whose discharge diagnosis was stroke, 55% arrived by EMS and 45% arrived by private transportation. Patients arriving by EMS with hospital pre-notification were more likely to have brain imaging completed within 25 min (RR= 3.0, 95% CI 2.1-4.1) and to have the results interpreted within 45 min (RR= 2.7, 95% CI 2.3-3.3) compared to arriving by private transport. Patients eligible for t-PA were more likely to receive it if arriving by EMS with pre-notification (RR=1.5, 95% CI 1.1-1.9). In the same study, compared with patients arriving by private transport, those arriving by EMS without hospital pre-notification also had a higher likelihood of having brain imaging completed within 25 min (RR= 1.9, 95% CI 1.6-2.3) and interpreted within 45 minutes (RR= 1.7, 95% CI 1.4-2.1. Berglund et al. (2012) found that patients assigned an upgraded priority level by dispatching personnel experienced fewer delays along the chain of stroke care from symptom onset to arrival at a stroke unit and were more likely to be treated with t-PA compared with patients who had been assigned to a standard-priority level by the emergency medical communications centre. Dalloz et al. (2012) included the results from 10 studies in a systematic review examining the use of pre-hospital stroke codes. A stroke code system was defined as efforts to improve the identification, transport and presentation of suspected stroke patients to the emergency department. The odds of treatment with thrombolysis were highest in settings that had a pre-hospital stroke code system in place compared with facilities with no stroke code (OR= 5.43, 95% CI: 3.84-7.73, p<0.001), and were lower in studies comparing pre-hospital stroke code with in-hospital stroke codes (OR=1.97, 95% CI: 1.53-2.54, p<0.001).

To rapidly identify persons with suspected stroke so that they can be transported to a stroke centre or other appropriate facility and treated promptly, the use of on-scene screening tools is recommended. Common pre-hospital screening tools, which have been validated previously include the Cincinnati Prehospital Stroke Scale (CPSS)(Kothari et al. 1999), Los Angeles Prehospital Stroke Screen (LAPSS)(Kidwell et al. 2000), Melbourne Ambulance Stroke Screen (Bray et al. 2005), Ontario Prehospital screening tool (Chenkin et al. 2009), and the Recognition of Stroke in the Emergency Room (ROISER) scale (Mingfeng et al. 2012). The CPSS is a 3-item tool that is intended to identify suspected stroke patients and whether they may be potential candidates for thrombolysis. The presence of anyone of the following indicates a positive screen: facial drooping, arm drift or abnormal speech. The LAPSS also includes facial droop and arm drift as scale items, but also includes criteria associated with patient history, including age, history of seizure, pre-morbid independence, blood glucose measure, and time of symptom onset. A stroke is suspected when all history criteria responses are ``Yes” and there is at least one abnormal physical symptom (Kothari et al., 1999). The MASS, Ontario Prehospital stroke screen and the ROISER contain items that are included in the CPSS and LAPSS but use a different scoring system. The ability of these tools to identify correctly persons with stroke (using the final discharge diagnosis as the reference standard) ranged 88% to 91%, while their ability to identify correctly those persons who had not suffered a stroke from 74% to 99%.

Blood glucose measurement is an important component of paramedic protocols; however, there is limited evidence to support the initiation of blood glucose control in the pre-hospital setting. Nurmi et al. (2011) evaluated the effect of IV and subcutaneous insulin therapy (compared with a no-treatment control group) in the pre-hospital setting when plasma glucose level exceeded 6.0 mmol/L. Although blood glucose levels were significantly lower at the point of arrival to hospital in patients treated with IV insulin administration (mean difference compared with control group was -1.9mmol/L, 95% CI -3.5 to -0.27), the protocol extended the time EMS personnel spent on scene (median =29 minutes). The use of subcutaneous insulin was not associated with q significant reduction in blood glucose (MD= -0.9mmol/L, 95% CI -2.4 to 0.6) and also increased time spent on scene by a median of 20 minutes. In general, few studies examining specific interventions associated with the pre-hospital phase of stroke care have been published.