Nov 3, 2018
“The value of experience is not in seeing much, but
in seeing wisely.”
― Sir William Osler
Deciphering signal from noise as it relates to modern stroke
care can be challenging and conflicting, especially as it pertains
to the out of hospital environment. In this podcast, we brought the
knowledge and experience of Dr. Ben Newman: a neurosurgeon and
endovascular therapy expert to discuss advances, challenges, and
strategies in caring for our stroke patients.
When to Bypass
Perhaps the most challenging decision to make when presented
with a patient experiencing an acute stroke is the transport
decision. Should we transport them to a Comprehensive Stroke Center
(CSC), or to a "thrombolytic capable center"?
The 2018
AHA/ASA Stroke Guidelines state that:
When several IV alteplase–capable hospital options exist within
a defined geographic region, the benefit of bypassing the closest
to bring the patient to one that offers a higher level of stroke
care, including mechanical thrombectomy, is uncertain. Further
research is needed.
They also state that the
Mission: Lifeline Severity–based Stroke Triage Algorithm for
EMS may be reasonable in some circumstances. This
algorithm recommends, in some circumstances, transporting the
patient to a comprehensive center only if the transport time is
"<15 additional minutes compared with the travel time to the
closest primary stroke center or acute stroke-ready hospital." In
the podcast, Dr. Newman believes that the travel time past a
"lytic" capable center should be limited to 20, maybe even 30
minutes.
Where you transport stroke patients to should be determined by
your local protocols and Medical Director in coordination with
local experts. Here are a few considerations:
- Patients with contraindications to thrombolytics may still be
candidates for thrombectomy.
- Last Known Well (LKW) isn't much of a factor in thrombectomy
decision making. Patients with a "wake up stroke" may still be
thrombectomy candidates depending upon the results of CTA and
perfusion imaging.
- Comprehensive Stroke Centers typically see a high volume of
stroke patients and have a well established work flow that results
in above average door to needle times. Transporting the patient
further might result in an overall shorter time to thrombolytic
administration.
- Most patients with LVO, although candidates for thrombolytics,
are less likely to respond, and may be at increased risk for
intra-cerebral hemorrhage.
When to Suspect LVO
It should be noted that the prevalence of LVO varies greatly in
the literature, ranging anywhere from 5 to 50%, meaning that very
There are multiple stroke severity algorithms of which even less
consensus exists! Essentially, these scales that were originally
developed and validated to recognize strokes have been adapted by
adding percentage points to determine severity. So, most of
your stroke "screening" tools now have an associated "severity"
tool.
The bottom line is, pick one screening tool for your department,
preferably the one you currently use, and use the "sister" severity
tool and get really good at it, then evaluate for over or under
triage.
Our (Curbside to Bedsides) recommendation is that if your
department doesn't have a standardized severity tool patients who
are having classic, unequivocal stroke symptoms (dominant
hemisphere deficits, gaze deviations, flaccidity, speech deficits,
etc.), are likely experiencing a LVO.
References
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J. P., Ortega-Gutierrez, S., … Lansberg, M. G. (2018). Thrombectomy
for Stroke at 6 to 16 Hours with Selection by Perfusion Imaging.
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https://doi.org/10.1056/NEJMoa1713973
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