Answer: Thanks for the question. We are sorry that you don’t agree with the current Stroke Guidelines.
The stipulation that the patient must arrive to a Designated Stroke Centre within 3.5h of a clearly determined time of symptom onset or the time the patient was “last seen in a usual state of health” is one of the most common questions we receive from paramedics. Interestingly, this is also one of the most common protocol violations from the Paramedic Prompt Card for Acute Stroke Protocol and one of the most common complaints the Stroke Neurologists refer back to the Base Hospital for investigation.
The Prompt Card was created from a joint working group of neurologists and emergency physicians and is designed to reflect the latest in clinical practice.
As you know, recently the window was expanded to 3.5h. A good review of the literature for the rationale for this decision can be found here: http://stroke.ahajournals.org/content/40/7/2438.full.pdf+html
Dr. Lewell recently presented this information via Webinar and in live rounds. The specific “last seen well” criteria and rationale were discussed at that time. The audio from these presentations can be found on our website here: www.lhsc.on.ca/About_Us/Base_Hospital_Program/Education/Paramedic_Rounds.htm
Unfortunately, we know from experience that as soon as we vary from the very strict protocols for thrombolysis, the frequency of complications (and specifically intra-cerebral hemorrhage) increases. Evidence for this can be found here: http://stroke.ahajournals.org/content/32/1/12.full.pdf+html
And specifically related to the time interval you mention “from last seen well” from the Cleveland experience: http://jama.ama-assn.org/content/283/9/1151.full.pdf+html
In reference to your comments that the current evidence suggests that the time window should be increased again, while this may occur in the future as experience with thrombolysis for stroke grows, the latest update from the American Heart Association clearly suggests that the current practice in Ontario in consistent with best practice. The AHA guidelines for stroke can be found here: http://circ.ahajournals.org/content/122/18_suppl_3/S818.full.pdf+html
Bottom line: Your suggestion of erring on the side of caution and giving the patient in the case you describe the benefit of doubt may actually increase their risk of harm from TPA.
A couple of points about your case: You describe a patient suffering from a stroke as being unconscious. Remember, most often, patients need to have a bi-hemispheric insult to their brain in order to be unconscious. Given the duplicate bilateral vascular supply the brain receives, it is not common for a true ischemic stroke patient to be unconscious. The altered GCS (< 10) on the Prompt Card is designed to allow a patient to have completely lost speech (complete aphasia = 1 out of 5) and still be a candidate for “Stroke Bypass”. A further fall of 2 points to < 10 would suggest that another process is in place affecting the patients level of consciousness. It is not clear that the length of time lying on the floor can be directly or accurately linked to level of consciousness as you suggest.
Finally, from a patient safety point of view, it is also not clear that transporting unconscious patients for up to two hours to a designated stroke centre can be done safely without advanced airways and/or other interventions. This may also further increase the risk of harm to patients.