Rural Stroke Care for Prehospital Providers

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 therapiesFocus on intravenous thrombolysis

Role of EMS in stroke systems of care:Activation of 911 Identification of stroke pt in the fieldAppropriate pre-hospital careTransport

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

homeWent 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 world1 person disabled every 45 seconds in US

Third leading cause of death in US700,000 strokes/year in US

Washington state:26,612 hosp and 3,167 (6.9%) deaths (2005)

Pathophysiology of strokeAngiographic 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

Intravenous thrombolytic Intra-arterial thrombolytic Mechanical

Opening the occluded artery

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

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

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 95% CI

090 2.8 1.84.5

91180 1.5 1.12.1 181270 1.4 1.11.9 271360 1.2 0.91.5

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

Informed consent, example: “There is a treatment for your stroke called t-PA that must be given

within 4.5 hours after the stroke started. It is a ‘clot buster’ drug that can lead to some improvement in one of every three patients treated. However, it has a major risk, since it can cause severe bleeding in the brain in about 1 out of every 15 patients. If bleeding occurs in the brain, it can be fatal. It is estimated that of 30 patients treated, one is harmed by the treatment. Overall, it is estimated that t-PA treatment is 10 times more likely to help than to harm eligible patients. When used to treat large numbers of stroke patients, on average the potential benefits of this treatment outweigh the risks; however, in any individual patient it is a very personal decision.”

Oliveira-Filo et al, UpToDate, October 15, 2008

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 available28.3% arrived within 60 minutes31.7% 1-3 hours40.1% > 3 hours

Jeff Saver, Feb 18, 2009, ASA International Stroke Conference

How long does it take to begin rtPA after pt arrives at hospital?• 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

Goal treatment timeline for door-to-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?

PainlessUnlike 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

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. Early hospital notification

Confirm availability of CTSpecify F.A.S.T findings

Consider air transport in remote areasEMS responders simultaneously call for air

transport and prenotify ED at receiving stroke center in some systems

Management en route

Lay patient flat unless airway compromiseDon’t elevate head greater than 20 degrees

IV access16 or 18 gage if possibleAvoid 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 publishedTechnical issues with portable

videoconferencing, transmittle of CT scansFinancial issues: reimbursementLegal 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 safeSeveral 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, thenEvery 30 minutes for six hours, thenEvery 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 hospitalGenerally 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 planningContinuous case-based feedback to EMS

personnel Hospital systems to shorten door-to-needle

time

Questions? Q & A

Follow-up questions:Dr. Hogness: [email protected]

Network questions & future trainings:Coordinator: [email protected]