Date Published

September 29, 2022

Updated For

ALS PCS Version ALS PCS Version 5.2


I recently attended a CVA/TIA related call; it had been the first CVA related call I had been to since having a 4-year hiatus out of the trucks. Since being out the trucks the CVA consult/bypass protocol has been implemented. I'm having a difficult time understanding the point of the consult. If the Paramedic on scene is able to identify CVA symptoms accurately/appropriately, why are we delaying transport to discuss with a physician, who is not on scene, if we should transport to the appropriate stroke facility? It was explained to me that Paramedics weren't correctly identifying CVAs pre-hospital. If that's the case, those that aren't recognizing a CVA aren't performing a consult because they didn't recognize the CVA in the first place. If I can identify a CVA correctly, announce a code stroke to dispatch, and have the stroke team ready on our arrival, how can there be any benefit to calling someone who knows nothing about the incident other than what I tell them? What is the difference between a doctor incorrectly identifying the CVA over the phone versus the Paramedic incorrectly identifying the CVA on scene other than the 15 minutes saved not trying to call for a consult? There also seems to be some significant discrepancies as to the onset of symptoms time frame between different receiving hospitals and physicians. Our destination guidelines clearly state within 6 hrs of onset of symptoms; however, recently a fellow medic advised me that it was 8 hrs but our guidelines have not yet been changed to reflect this, and a physician told me the window is 12 hrs. Any clarification/suggestions/info would be greatly appreciated. Thank you so much!


First off, welcome back to clinical practice. Its nice to have you helping keep our communities safe again.

As you mention, there have been some changes to the Stroke Bypass system over the past 4 years. One of the changes is the simplified timeline for consideration of Stroke Bypass from 4.5 or 6 hours depending on Endovascular Therapy (EVT) being available (BLS-PCS 3.1) to simply: 6 hours. The most updated version of the Stroke Bypass Protocol can be found in the BLS-PCS v3.3 (here). The Protocol states, if the patient meets the criteria listed in paragraph 1, determine if the patient can be transported to a Designated Stroke Centre within 6 hours of a clearly determined time of symptoms onset or time the patient was last seen in his/her usual state of health.

The involvement of a stroke neurologist in consultation for stroke bypass is a regional policy. Paramedic Services and Stroke Centres may choose to include this in their local Bypass agreement (i.e. Paramedic Services and the hospitals that serve as Stroke Centres negotiate some specifics of the agreement based on local/regional factors). The discussion with stroke neurologist in the field facilitates team activation and their arrival at hospital to initiate care, decreasing door to needle time (similar to STEMI). Understanding the type of case directly from prehospital history facilitates early neurologist warning for EVT team should that be an option. This has moved beyond field QA of medics identifying strokes. Early numbers 15 years ago showed 6 EMS transported as a stroke, for each true stroke, current data is 1.5 to 1, with stroke mimics often still being sorted out at stroke centre. Usually, the Paramedic Service is part of the Regional Stroke Team and sends out local data.

For further information on the recent changes to the Stroke Bypass Protocol and Paramedic Prompt Card, please see the Corhealth Ontario resources (here). This resource provides multiple resources including a video explaining the rationale for the changes to paramedic practice, along with references for a deep dive into the Canadian Stroke Best Practices.

With regards to timing of treatment outside the scope of paramedic and transport protocols: Tissue Plasminogen Activator (tPA), the IV medication that dissolves clot must be delivered within 4.5 hours of stroke symptom onset. Mechanical removal of a clot with EVT is ideally performed within 6 hours of stroke symptom onset. However, the time window may be extended up to 24 hours, depending on a very selected patient subgroup, with proven specific findings on advanced imaging. Again, this falls outside of the scope of practice for paramedic decision-making. Follow the BLS-PCS and any Service- Stroke Center Bypass agreements.



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