EMS and Pre-Hospital Screening of Acute Stroke Patients
EMS and Pre-Hospital Screening of Acute Stroke Patients
How are decisions made for stroke patients prior to coming into the hospital?
Content
2.12 -> all righty good morning everybody thank
4.44 -> you very very much for coming out here
6.54 -> and the you know the world of stroke has
8.94 -> come a huge way because when I first
10.92 -> started speaking about stroke
13.17 -> I had audience as well in the 4 to 6
15.269 -> people range and this is really
17.58 -> tremendous all righty so I just wanted
20.64 -> to let you know that I have only one
23.73 -> major disclosure and that is that I'm
25.71 -> very honored to be here today with my
27.84 -> colleagues and with all of you so thank
29.609 -> you all for coming I'd like to talk a
31.949 -> little bit about emergency medicine
34.07 -> pre-hospital systems and and kind of the
37.829 -> screening tools that they use in the
39.45 -> pre-hospital environment and to kind of
42.329 -> figure out you know how they actually
43.469 -> make decisions on who to transport where
46.53 -> and when and what time frame and and so
50.399 -> you know clearly 12 minutes is more than
52.559 -> enough to discuss this topic and you'll
58.02 -> understand why at the end so we all kind
61.32 -> of are here because we know that strokes
62.85 -> are fairly common that that there's a
66.21 -> fairly high mortality with strokes it's
68.04 -> a number two killer in the world and
69.9 -> it's number four in the United States
71.88 -> and that there's a significant morbidity
73.68 -> to it and that morbidity it translates
76.53 -> to six and a half million stroke
78.09 -> survivors in the United States and
79.83 -> really the amount of disability that it
81.689 -> causes is really our major problem in
84.259 -> managing strokes and so all of our
86.58 -> effort really is to decrease the
88.47 -> disability as well as do our best to
91.77 -> decrease mortality in the acute stroke
93.6 -> patients we also know that that was a
97.95 -> large vessel occlusion and LVO which is
101.009 -> becoming you know the term that we all
103.079 -> hear on a daily basis that that you have
107.729 -> severe ischemia to the brain and that
110.25 -> this ischemia is very time dependent and
112.5 -> that you lose about 1.9 million neurons
115.259 -> per minute in a large vessel occlusion
117.84 -> one about 14 billion synapses and and
123 -> then about seven and a half miles of
125.13 -> axonal fibers per minute of occlusion so
128.55 -> time is clearly very important now
131.75 -> having that back
133.56 -> I would just like to kind of go over for
135.39 -> those of you that don't live in the EMS
136.86 -> world you know how things are organized
139.53 -> in in EMS it kind of started back in the
143.52 -> 60s and 70s when people realized that
147.33 -> your chances of dying from a motor
149.97 -> vehicle accident on the highway was
152.85 -> greater than if you had gotten shot in
155.489 -> combat in Vietnam and and from that
159.18 -> point they said we really have to do
160.65 -> something about this and back then the
162.72 -> ambulances were also hearses and they
165.54 -> were just you know large station wagons
167.43 -> and and that was the extent of our ems
170.34 -> system and was very informal so there
173.25 -> was legislation passed in 1966 and again
176.1 -> in 73 the big ems Act of 1973 created
180.209 -> our ems systems but these systems are
182.55 -> under local control and the state each
185.1 -> state creates local regions called MCAS
188.819 -> and the MCAS our medical control
190.65 -> authorities and they're made up the
193.44 -> medical control authorities themselves
195.09 -> are made up of all the hospitals in that
196.98 -> region that actually have their doors
199.739 -> open 24/7 to receive patients and so
203.07 -> these committees in each region make up
206.15 -> all of their protocols and certain rules
209.07 -> but then those are supervised by the
210.84 -> state so that there's some consistency
212.88 -> and some minimal correlation to what the
216.57 -> state wants for EMS care the funding for
219.84 -> these things out varies a you know
221.7 -> extremely widely from community to
223.44 -> community it could be public could be
225.6 -> private or could just be volunteer
227.28 -> services and the way they're organized
229.59 -> is extremely variable based on their
231.959 -> resources so in some communities you
234.18 -> have people that are both firemen and
235.65 -> paramedics and other places those two
237.959 -> are separate and the amount of training
240.51 -> for paramedics varies tremendously also
243.69 -> the other thing is that they work on
245.579 -> protocols and the protocols may be
247.5 -> either online meaning that there's a
249.84 -> physician on the phone or through some
251.489 -> kind of telemetry process with them or
253.709 -> they could just be run by protocols were
255.72 -> where the paramedics go in the field and
257.82 -> just run what they do based on on pre
260.4 -> established protocols so the training
263.61 -> for these people is extremely variable
265.68 -> and if you take a look around the Unites
267.51 -> States there's over 30 types of
269.7 -> paramedics that are operating out in the
272.1 -> field but we kind of divide them into
274.29 -> kind of three levels a basic which has
277.14 -> about a hundred hours of training and
278.94 -> this person can go out and do CPR
281.01 -> intubate and they have a DS with them
283.68 -> these automatic defibrillators
285.86 -> intermediate who can do a little more
287.82 -> they have 300 hours of training and they
290.19 -> can do IVs and certain medications and
293.13 -> EKGs and then a full paramedic with over
295.56 -> a thousand hours of training that can
297.75 -> has extended use of medication so it
300.45 -> depends on the resources or the
302.4 -> individual community that you live in
304.64 -> that actually dictates what the level of
308.67 -> training is for your pre-hospital care
310.73 -> personnel so I'd like you to kind of
313.89 -> imagine yourself sitting in your living
316.02 -> room watching the Lions game and clearly
320.7 -> you know I know these guys aren't
321.87 -> watching the Lions because they're all
323.34 -> smiling and so I know that this is a
327.36 -> little bit of a stretch however assume
330.33 -> that you're kind of on a Sunday
331.56 -> afternoon at home with your family
333.33 -> watching watching TV hanging out and all
336.6 -> of a sudden you have a stroke and and
339.6 -> you can't move and you and you can't
342.33 -> talk and you're not really sure what's
344.79 -> going on you know what is it that you
347.07 -> would like to happen if you were stuck
349.5 -> in that position you know and and I
352.23 -> think that that putting yourself in to
354.18 -> the patient's point of view kind of
356.28 -> helps you develop ideas about what we
359.7 -> should do to respond to patient care
361.38 -> needs and that's kind of a real panic
363.3 -> situation and what you're hoping for is
365.82 -> that somebody recognizes that you're not
369.21 -> right even if you can't you know really
372.03 -> talk and it's and it's very different
373.56 -> it's not like a heart attack where you
375.03 -> can go oh my god my chest is hurting or
377.96 -> you know or if you got shot and you're
380.37 -> you know dripping blood on the floor
381.87 -> people notice and so you want to make
385.05 -> sure that your family members know
386.61 -> what's going on and that you get their
388.86 -> attention and that they actually call
390.84 -> 9-1-1 and that when they call 9-1-1 the
394.32 -> person who's answering the phone at
396.06 -> night and when the dispatcher
397.58 -> understands that this could be a stroke
399.75 -> and that you actually
401.289 -> get the right resources out to that
403.089 -> patient and that the paramedics or the
405.789 -> EMS people get there very fast and that
408.58 -> once they're there they figure out
409.93 -> what's going on and get you and maybe a
412.479 -> family member to the right place
414.369 -> so getting you know the right person to
416.559 -> the right place and the right time is
418.089 -> absolutely key and you know recognizing
421.36 -> the symptoms is not as easy as you think
424.149 -> and we kind of struggle with this all
425.8 -> the time if you have a mi you know you
427.96 -> have an EKG that tells you exactly
429.639 -> what's going on and you have patients
431.499 -> with symptoms and if you get stabbed or
433.809 -> shot you know you have obviously the
436.24 -> trauma that that gets you in and this
438.879 -> this young man who was eviscerated was
441.129 -> actually a patient that I took care of
442.689 -> and of course you know when he got
445.24 -> stabbed and he eviscerated on the street
447.869 -> everybody you know noticed it and
450.729 -> panicked and called EMS and we got all
453.759 -> these systems going we got you know the
455.649 -> trauma surgeons anesthesia a
458.169 -> resuscitation room and we basically took
461.199 -> the guy up and and you you know run his
463.629 -> bowel and rinse them out and tuck it
465.069 -> back in and they have a two percent
466.419 -> mortality and with the stroke patients
469.12 -> you may have up to a twenty percent
470.919 -> mortality at one year and nobody's
473.439 -> really kind of you know getting in a
475.24 -> rush or panicking so I think that with
477.069 -> the current treatments we have we need
478.99 -> to change that paradigm so you want your
481.36 -> people to actually recognize that
483.189 -> there's something wrong with you and and
485.529 -> that's the face arm speech and time kind
487.93 -> of thing and hopefully they'll learn
489.759 -> about that and you want them to call 911
492.49 -> barsen many years ago actually figured
495.129 -> out that if you call 9-1-1 that's the
497.529 -> fastest way to get into the emergency
499.18 -> department and that if you call your
501.189 -> private physician that's the slowest way
503.559 -> to get into the emergency department and
505.36 -> yet that's kind of you know your natural
507.819 -> reflex is to call your doctor so that
509.68 -> you kind of have to change that a little
511.749 -> bit so our expectations of EMS are that
515.469 -> they actually get there in time they
517.12 -> figure out what's going on with the
518.889 -> patient and get them to the right place
522.159 -> the dispatchers really need to use very
524.5 -> focused questions to get to the bottom
527.889 -> of what's happening with the patient so
529.75 -> that they can tell the paramedics you
531.639 -> know what kind of run they're on
533.11 -> they can prepare for it and really one
535.269 -> of the most difficult things is to
537.579 -> figure out when was the patient last
539.86 -> normal so if you're sitting in your
541.66 -> living room
542.32 -> and you can't speak and you can't move
544.12 -> nobody notices that there's something
546.339 -> wrong so so they'll have to go back
548.56 -> oh yeah right you know half hour ago he
550.72 -> got up and went to the bathroom and
552.25 -> that's that now that becomes your time
554.98 -> so once the paramedics get there they
557.38 -> have to deal with the ABCs the airway
560.709 -> breathing circulation and they actually
562.329 -> look at your c-spine also to make sure
564.339 -> that there's no Associated trauma with
565.99 -> this they check your glucose you know
568.57 -> and then they then they may operate on a
570.579 -> protocol or they may call in they also
572.92 -> have to kind of do some kind of
574.75 -> pre-hospital stroke scale and there are
578.17 -> two kinds one that actually helps you
579.94 -> identify a stroke and one that actually
582.79 -> tries to help you identify if there's a
585.16 -> large vessel occlusion or not and as you
587.89 -> can see there's a ton of these things
589.45 -> out there and so this slide is not
591.55 -> intended for you to really understand
594.13 -> any of these things whereas this slide
596.98 -> is so and so you can see that all of
602.17 -> these scales have been tested they all
604.24 -> have their sensitivities and
605.5 -> specificities likelihood ratio is a
608.079 -> positive and negative you know and and
610.3 -> they all kind of compete with each other
611.74 -> for you know which is the best one but
614.05 -> the fact that there's so many of them
615.64 -> means that none of them are really
617.88 -> sufficiently adequate to do what you
620.589 -> really want to do which is you know you
623.17 -> need a psychic with you to know if
625 -> there's a a large vessel occlusion when
628.42 -> you first show up at the patients house
630.07 -> so so really you have to kind of look at
634.029 -> these and I know that over time there's
635.769 -> going to be more and more data on this
637.54 -> there's a couple validated ones the
639.699 -> Cincinnati pre-hospital Stroke Scale in
641.769 -> the Los Angeles pre-hospital stroke
644.079 -> screen that have undergone some testing
645.88 -> and Steve Levine's group has kind of
648.31 -> done these graphs and looked at all the
649.899 -> data on them and has created receiver
652.06 -> operator curves that tell you how good
654.04 -> their sensitivity is and how low their
656.23 -> false positive rates can go and you know
658.899 -> that the laps score the Los Angeles
661.39 -> pre-hospital Stroke Scale has 86 percent
664.75 -> sensitivity and a 99 percent
666.7 -> specificity which i think is really you
669.28 -> know pretty good
670.15 -> Cincinnati though is much much more
672.16 -> simple it's not an 11 item score it's a
674.35 -> three item score and it's at 80 percent
676.9 -> sensitivity and 88 percent specificity
680.08 -> so I think for for that scale being as
683.26 -> simple as it is it's really quite
685.21 -> effective and so this is the to
687.82 -> comparison so when pink is the LA Stroke
690.22 -> Scale and and in blue is a Cincinnati
692.62 -> Stroke Scale and you can see these are
694.24 -> all various studies that have mapped out
696.73 -> their various characteristics so it's
698.95 -> not really important to know this right
700.6 -> now but what's important to know is that
702.85 -> the American Heart has come up with an
704.44 -> algorithm that basically says when EMS
707.8 -> arrives they have to examine the patient
709.57 -> and they should do some kind of screen
712 -> to actually decide if it's a stroke and
714.61 -> then if you think it's a stroke you
716.41 -> should do a screen to decide if it's a
718.3 -> larger vessel occlusion and if it's a
720.52 -> large vessel occlusion and they're
722.8 -> within six hours and that paradigm is
725.53 -> changing and we'll hear more about that
726.94 -> today
727.69 -> then you should transport them to an
730.87 -> institution that actually can do a
733.33 -> thrombectomy and has endovascular
736.81 -> therapy if it only adds another 15
740.83 -> minutes of transport on to your already
742.63 -> usual transport time and so that's kind
745.54 -> of the American Heart algorithm and
747.55 -> they've worked on this for a long time
748.9 -> and there's data supporting each box in
751.6 -> each circle but I think one of the
753.97 -> interesting things that has just
755.17 -> recently developed is something that was
757.48 -> published just recently by Andrew
759.73 -> ASIMO's in North Carolina and Bogle
763.39 -> who's a epidemiologist and they
765.46 -> basically created a simulation and so
769.3 -> they know that the person is going to
770.53 -> call 9-1-1 EMS is going to be dispatched
773.62 -> and that when they arrive they're going
775.9 -> to do a unseen score and look for an LV
779.89 -> oh and if it's not there they're gonna
781.99 -> transport to the nearest hospital it if
783.85 -> it is there they're going to transport
785.95 -> to the nearest endovascular center and
788.08 -> in this model what you can do is
790.24 -> actually look at your stroke prevalence
792.13 -> in your county and create simulations
795.1 -> for various patients based on where
797.23 -> they're you live what their odds are of
798.97 -> having a
799.55 -> stroke and then you can actually plug in
801.589 -> various different transport times
803.87 -> various different times of day and then
806.269 -> they were use MapQuest to figure out
808.07 -> what the transport times will be and
809.87 -> then you can use various different
811.82 -> stroke scales so you can actually use
814.43 -> this model for your own community and
816.47 -> they actually looked at two counties
818.3 -> Mecklenburg County which is Charlotte
820.16 -> North Carolina and then King County
822.5 -> which is Seattle and Seattle has a fair
826.459 -> amount of mountainous regions around it
828.26 -> that are hard to transport and and they
830.899 -> tried to figure out there over triage
832.79 -> rate which is how many people are you
835.19 -> gonna actually over triage to
837.5 -> endovascular centers that could have
839.54 -> gone to their local or their closest
842.36 -> Primary Stroke Center and the over
844.64 -> triage rate for Mecklenburg County was
847.31 -> between 13 and 55% and for King County
850.31 -> was 10 to 40% and it's interesting that
852.98 -> you can't make a single statement about
855.44 -> everybody in the country what you can
856.94 -> say is that every environment is
859.73 -> different and you need to figure it out
861.44 -> in that environment and model for that
863.899 -> environment and they came up with this
865.67 -> know like number needed to route so how
868.7 -> many people do you need to route to a
871.37 -> center that can do endovascular therapy
874.089 -> in order to get one LVO patient there
878.48 -> and so using the lambs score it was
882.079 -> about 2.6 using the race scores about
885.14 -> 5.3 and using SI stat which is another
888.2 -> Cincinnati scale it was nine point three
890.6 -> and so depending on your environment
893.56 -> right because Cincinnati wants everybody
896.06 -> to come to them and so but the thing is
901.85 -> that you have to decide what's an
903.529 -> acceptable false positive rate how many
905.42 -> LV OS are you willing to send to places
908.899 -> that don't have endovascular so
911.41 -> ultimately as I finish up here with my
914.12 -> conclusion there's an extreme
916.25 -> variability in systems
918.42 -> there's no consensus on which stroke
921.18 -> scales to use you have to get involved
924.84 -> it took five years to do the TPA study
927.96 -> and 20 years to implement it so get
932.4 -> working and as a transition I would just
935.97 -> like to say the big parameters are on
939.9 -> set to reperfusion and it's an entire
943.17 -> system and so we're hopefully going to
945.84 -> hear about how to cut that system short
948.3 -> by field treatment thank you
950.94 -> [Applause]
Source: https://www.youtube.com/watch?v=zMYP5nN5dUc