Rural Stroke Care for Thank you for joining us! Prehospital - - PDF document

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

• f 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

• cclusive 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

• utcome: 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

• cclusions

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

• utcomes

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

0−90 2.8 1.8−4.5 91−180 1.5 1.1−2.1 181−270 1.4 1.1−1.9 271−360 1.2 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 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?

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

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 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

• f affected hemisphere, parenchymal

hypodensity, and/or effacement of >33%

• f 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-to-

needle time

Questions?

Q & A Follow-up questions:

• Dr. Hogness: cchogness@methownet.com

Network questions & future trainings:

Coordinator: chara.chamie@doh.wa.gov