Transcript STROKE 2009 - INHS Health Training

Rural Stroke Care for
Prehospital Providers
Chris Hogness, MD
Telehealth Training
March 17th, 2010
Northwest Regional Stroke Network
Welcome

Thank you for joining us!

Format

Introductions
What we will talk about today



Evidence behind current stroke therapies
 Focus on intravenous thrombolysis
Role of EMS in stroke systems of care:
 Activation of 911
 Identification of stroke pt in the field
 Appropriate pre-hospital care
 Transport
System planning for improved care
CASE

Previously healthy 48 yo man
 History
of migraine HA, last episode 1 yr
ago
 Possible episodic hypertension remotely,
normal blood pressure in recent visit to
PCP
 Low grade hemoglobin A1C elevation: 6.2
 Normal LDL cholesterol: 100
 No family history of vascular disease
CASE, continued

Experienced episode of weakness, fell at
home
 Went
back to bed
Awoke 1 hour later with speech difficulty
and left hemiparesis
 EMS activated:

 Delay
in reaching rural location, paramedics
chain up to get to his home
CASE, continued

Taken to local t-PA capable, critical
access hospital
Head CT done: no acute change
 Phone consultation with neurologist 2 hrs away
 Time since last normal 4 ½ hrs
 Recommendation for no TPA, not given
 Transferred to larger hospital

CASE, continued

Further evaluation:
MRA brain: Acute stroke involving posterior
division of R MCA
 MRA neck: Complete occlusion proximal R internal
carotid
 F/U CT brain 4 days after event: Interval extension
of large R MCA infarct with surrounding edema
 Specials:

TEE with bubble: no PFO
 Hypercoagulable w/u negative

Stroke kills and disables many

Most common cause of disability in the
world
1

person disabled every 45 seconds in US
Third leading cause of death in US
 700,000

strokes/year in US
Washington state:
 26,612
hosp and 3,167 (6.9%) deaths (2005)
Pathophysiology of stroke
Angiographic and autopsy studies reveal
approximately 80% of strokes caused by
occlusive arterial thrombus
Brain cells die quickly in stroke

1.9 million neurons lost per minute
 Initial
ischemic penumbra, area of decreased
perfusion with neurologic dysfunction which
may not be permanent if flow restored

Time window for clinical benefit of opening
artery challengingly brief
Opening the occluded artery
Intravenous thrombolytic
 Intra-arterial thrombolytic
 Mechanical

Recanalization (restoring flow)
rates by intervention
Spontaneous: 24.1%
 Intravenous thrombolysis: 46.2%
 Intra-arterial thrombolysis: 63.2%
 Combined IV and IA thrombolysis: 67.5%
 Mechanical: 83.6%


Rha et al: The impact of recanalization in ischemic stroke
outcome: a meta-analysis. Stroke 2007: 38:967
Recanalization (restoring flow)
rates by intervention, update
 1,122
severe stroke patients at 13 academic
centers between 2005 and 2009
 Treated with one or more of:
intra-arterial tPA
 intracranial stenting
 IV delivery of tPA in the arm
 Merci Retriever for clot removal
 Prenumbra aspiration catheter for clot removal
 glycoprotein IIb/IIIa antagonists
 angioplasty without stenting

Recanalization update,
continued



Patients treated with mechanical agents and drugs
(n=584) compared to those treated only with mechanical
therapy (n=274) or only drug therapy (n=264).
Successful recanalization in 68% of all patients
Recanalization rate for multimodal therapy patients 74%,
no higher incidence of hemorrhage.
 Stenting and IA TPA only independent predictors of
vessel recanalization during endovascular treatment.
ASA International Stroke Conference Feb 2010
Most patient outcome data from
intravenous thrombolysis

Intra-arterial, mechanical not randomized
with iv thrombolysis:
No RCT data comparing disability, death
 Improved flow may not correlate with improved outcome
depending on technique used (eg distal embolization)


Exact niche for each modality not
determined
Intra-arterial lower tPA volume, role in pts at increased
risk of bleeding
 Intra-arterial may be more effective for more proximal
occlusions

Intravenous thrombolysis
Multiple randomized controlled trials
demonstrate reduced stroke disability
 Consensus guidelines recommend:

American Heart Association
 American College of Chest Physicians


Regulatory agencies approve:
FDA 1996
 Canada 1999
 European Union 2002

National Institute of Neurologic Disorders
and Stroke (NINDS): NEJM 1995
• 624 pts with acute ischemic stroke, treated within 3 hrs of
symptoms onset
• Randomized to TPA vs placebo
• Complete/near complete recovery at 90 days:
•31-50% TPA vs 20-35% placebo
•Mortality not significantly different
•17% TPA vs 21% placebo
•10 fold increase in brain hemorrhage
•6.4% TPA vs 0.5% placebo
Stroke disability scores used in
NINDS trial and others




Modified Rankin scale: functional score
 0 = no symptoms; 5 = severe disability
Barthel index: activities of daily living
 0-100; 100 = complete independence
Glasgow outcome scale: function
 1 = good recovery; 5 = death
NIH Stroke Scale (NIHSS)
 42 point scale measure of neurologic deficit
NINDS favorable disability
outcomes



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Modified Rankin scale of 0-1:
 39% tPA vs 26 % placebo
Barthel index of 95-100:
 50% tPA vs 38% placebo
Glasgow Outcome Scale of 1:
 44% tPA vs 32% placebo
NIHSS 0-1:
 31% tPA vs 20% placebo
Pooled analysis of 6 tPA trials


2775 patients
 NINDS parts 1&2 (3 hr window)
 ECASS I and II (6 hr window)
 ATLANTIS A (6 hr window) and B (5 hr)
Findings:
 Benefit dependent on time from onset of symptoms to
treatment
 Hemorrhage 5.9% tPA vs 1.1% placebo
 Lancet 2004: 363:768-774
Favorable outcome at 3 months by time of
treatment: pooled data IV rtPA vs Placebo
Time (min)
Odds Ratio
090
2.8
91180
181270
271360
1.5
1.4
1.2
95% CI
1.84.5
1.12.1
1.11.9
0.91.5
Pooled tPA data: benefit vs time
3 hours
Pooled analysis of ATLANTIS, ECASS, and NINDS rt-PA stroke trials. Lancet. 2004;363:768
3 TO 4 ½ HOURS:
ECASS III: NEJM 2008

821 pts 18 to 80 yrs old with acute ischemic stroke for
whom treatment could be administered 3 to 4 ½ hrs from
stroke onset, randomized to tPA vs placebo
 52% no disability with tPA vs 45% placebo
 No mortality difference (7.7% tPA vs 8.4%)
 Symptomatic hemorrhage 7.9% tPA vs 3.5%
 NEJM 2008;359:1317-29
IV thrombolysis is underutilized
Currently, estimated 4% of patients with
ischemic stroke receive thrombolysis with
rt-PA
 Very short time window

Patients arrive late
 Hospitals may be slow to respond

How long does it take pts to get to
the hospital?

106,924 pts treated over 4 year period at
905 “Get-With-the-Guidelines” hospitals
for whom time of onset of stroke available
 28.3%
arrived within 60 minutes
 31.7% 1-3 hours
 40.1% > 3 hours
 Jeff Saver, Feb 18, 2009, ASA International Stroke
Conference
How long does it take to begin
rtPA after pt arrives at hospital?
•
Goal treatment timeline for doorto-needle
Evaluation by physician: 10 min
 Stroke expertise contacted:15 min
 Head CT or MRI performed: 25 min
 Interpretation of CT/MRI: 45 min
 Start of treatment: 60 min

Why do patients delay seeking
care for acute ischemic stroke?

Painless
 Unlike
myocardial infarction
Cognition may be impaired by the event
 Not calling 911

 1st

call to physician associated with delay
911 dispatch may fail to recognize sx or
not understand pt due to stroke
True/False: EMS response times
to suspected stroke should be
equal to response times for
suspected MI
AHA recommended goals for
EMS response time in stroke
Dispatch time < 1 minute
 Turnout time < 1 minute
 Travel time equivalent to trauma or MI
calls

What is the maximum on scene
time recommended for EMS
personnel prior to transport of the
patient with stroke?
Minimize on-scene time
Least is best
 No more than 10 minutes in assessment
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 Some

parts may be done in transit
Goal <15 minutes total on-scene time
True / False: EMS personnel
should use a validated screening
tool in assessing pts for stroke
EMS stroke assessment tools
Cincinnati Prehospital Stroke Scale
 Los Angeles Prehospital Stroke Screen
 F.A.S.T.

F.A.S.T.
Face
 Arm
 Speech
 Time last normal


If one component abnormal, 72%
probability CVA
Name several conditions that can
mimic stroke
Conditions mimicking stroke:
Hypoglycemia
 Seizure with post-ictal period
 Complex migraine
 Conversion disorder
 Drug ingestion

Over-triage
Err on the side of over-identification rather
than under-identification
 AHA: “Initially, EMSS should establish a
goal of over-triage of 30% for the
prehospital assessment of acute stroke”
 Lessons from trauma: if over-triage is not
present, under-triage will result

What routine pieces of history
should be obtained?
TIME LAST NORMAL
 Hx diabetes? Use of insulin?
 Hypertension? Medications used?
 Hx seizure disorder?

What piece of history is often not
included in prehospital
assessments?
Time last normal
EMS personnel often only medical
providers with access to all witnesses
 Transporting family/witnesses with patient
may help with treatment decisions at the
hospital

Prehospital treatment of stroke

True/False:
 __First
address ABCs
 __Run glucose containing solutions IV
 __Correct hypovolemia with IV saline
 __Correct hypoglylcemia when present
 __Administer aspirin
 __Administer oxygen in the non-hypoxic
patient
 __Keep pt NPO
Prehospital treatment of stroke

True/False:
 T__First address ABCs
 F__Run glucose containing solutions IV
 T__Correct hypovolemia with IV saline
 T__Correct hypoglylcemia when present
 F__Administer aspirin
 F__Administer oxygen in the non-hypoxic patient
 T__Keep pt NPO
Transport

Determine appropriate facility
 Closest
TPA capable if < 2 hrs from time last
normal

Assumes door-to-needle will be <60 min
 Primary
stroke center / Comprehensive stroke
center

State guidelines pending regarding appropriate
level of stroke center based on time last normal
Transport, cont.
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Early hospital notification
 Confirm
availability of CT
 Specify F.A.S.T findings

Consider air transport in remote areas
 EMS
responders simultaneously call for air
transport and prenotify ED at receiving stroke
center in some systems
Management en route

Lay patient flat unless airway compromise
 Don’t

elevate head greater than 20 degrees
IV access
 16
or 18 gage if possible
 Avoid glucose containing solutions
2nd exam/neuro reassess
 Perform TPA check list

What labs need to be sent on
stroke TPA treatment
candidates?
CBC including platelets
 Cardiac enzymes
 Electrolytes, BUN, creatinine, glucose
 PT/INR
 PTT

Name as many contraindications
to tPA as you can
Contraindications to TPA:
clinical

Symptoms/signs only minor or rapidly improving
Seizure at onset of stroke (not absolute)
Symptoms suggestive of subarachnoid hemorrhage
Persistent blood pressure elevation >185/110

Active bleeding or acute trauma



(fx)
Contraindications to tPA:
historical
Stroke or head trauma in prior 3 months
 Any hx intracranial hemorrhage
 Major surgery in previous 14 days
 GI or GU tract bleeding in previous 21 d
 MI in prior 3 months
 Arterial puncture at noncompressible site
previous 7 days

Contraindications to TPA: lab
Platelets less than 100K
 Glucose less than 50
 On oral anticoagulant with INR > 1.7
 On heparin with PTT higher than normal

Contraindications to TPA: CT
Evidence of hemorrhage
 Major early infarct signs (diffuse swelling
of affected hemisphere, parenchymal
hypodensity, and/or effacement of >33%
of middle cerebral artery territory)

Telemedicine and telephone
consultation

Several successful demonstrations
published
 Technical
issues with portable
videoconferencing, transmittle of CT scans
 Financial issues: reimbursement
 Legal issues: liability
Drip and Ship

Starting IV t-PA infusions for acute
ischemic stroke at community hospitals
prior to transfer to a regional stroke center
is feasible and safe
 Several

demonstrations published
Silva et al, ASA International Stroke Conference,
February 2009, others
How often do vital signs need to
be checked after the
administration of rt-PA?
Monitoring after rt-PA in stroke

Vital signs and neurologic status should be
checked:
 Every
15 minutes for two hours, then
 Every 30 minutes for six hours, then
 Every 60 minutes until 24 hrs from start of rx
Treatment of hypertension in
stroke

If no rt-PA given, best to leave any acute
treatment to hospital
 Generally
we do not treat acutely unless
>220/120

If rt-PA has been given:
 Systolic

>180, diastolic >105:
Labetalol 10 mg iv over 1-2 minutes, repeat every
10-20 minutes to max 300 mg
System improvement
Public education on signs/sx/rx stroke
 Fundamental role of EMS in getting pt to
appropriate center on time

 Integrate
EMS in planning
 Continuous case-based feedback to EMS
personnel

Hospital systems to shorten door-toneedle time
Questions?

Q&A

Follow-up questions:
 Dr.

Hogness: [email protected]
Network questions & future trainings:
 Coordinator:
[email protected]