Transcript Slide 1

STROKE
ACUTE CARE and
THROMBOLYSIS
Adrian Pace
Neurology SpR
Derriford Hospital
Types of Stroke
Stroke is several different
disease processes:
1. Small vessel disease
(atherosclerosis)
2. Large vessel disease (carotid
atheroma embolism)
3. Cardio-embolic disease
(AF; PFOs; LVF)
4. Cerebral haemorrhage
(aneurysms; HTN)
Acute care in a nutshell
• Oxygen, glucose, blood pressure
• Sa02 should be maintained at >=95%
• Blood glucose should be maintained between
4 – 11 mmol including use of insulin for known
diabetics
• Blood pressure should allowed to find its
normal level by ensuring normal fluid balance
Also in first 24 hours…
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Admit to an acute stroke unit direct from ED
Aspirin 300 mg
Swallow screen and SALT referral
Keep temperature down (fan, paracetamol)
Early mobilisation and PT referral
Avoid catheters unless in retention
National guidelines
• Everything you need is in the
• Royal College of Physicians National
Clinical Guidelines for Stroke
(3rd Edition) 2008
• This includes a comprehensive evidencebased guide to acute stroke care – what
works, what is pointless, what is still being
tested
THROMBOLYSIS
FOR
ISCHAEMIC STROKE
Ischaemic cascade in stroke
Process of stroke injury
at cellular level.
Irreversible damage begins
immediately at the core
(Umbra).
The surrounding area (Penumbra) is an ischaemic zone with CBF of 25-50% of
normal and loss of autoregulation.
Viability of penumbra is preserved if perfusion is restored with in a critical
time period.
Ischaemic Penumbra
Maintain blood
flow to penumbra
Maintain
cerebral
blood flow
Thrombolysis is the process of breaking up and dissolving intravascular blood clots by
pharmacological means.
Some commonly used thrombolytics are:
1.Streptokinase
2.Urokinase
3.Recombinant tissure plasminogen activators (rt-PA).
Thrombolysis is used for minimising tissue damage following myocardial infarction,
stroke, massive pulmonary embolism and acute limb ischaemia.
Thrombolysis reduces risk of long term disability after stroke by 30%
But only 0.2% received thrombolysis in UK in 2006 compared with 10% in
Australia. Derriford currently at about 1.5% of acute stroke admissions.
NAO estimate:
- cost of thrombolysis for 9% strokes to be £9.9 million
- saving of £26.4 million in care costs
EFFICACY AND
SAFETY OF
THROMBOLYSIS
Benefit vs Harm with Thrombolysis
For every 100 patients treated with rt-PA:
- 32 have a better final outcome
- 3 have a worse final outcome
- 65 have an unchanged outcome
NNT = 3.1
NNH = 30.1
Likelihood of being helped rather than harmed
LHH = 30/3 = 10
Intravenous rt-PA is 10 times more likely to help than harm eligible
patients with acute ischaemic stroke.
Risk of Cerebral Haemorrhage with rt-PA
6.4% risk of symptomatic ICH within
24hrs (ie, clinical worsening due to
new ICH) vs 0.6% without rt-PA.
1.5% risk of large haemorrhage
with significant space occupying
effect likely to prove fatal and not
usually amenable to surgery.
At three months mortality was
not significantly different
between the two groups
NINDS trial – 3 months outcome
ELIGIBILITY FOR
THROMBOLYSIS
Eligibility Criteria for treatment with rt-PA
• Age 18 to 80 years
• Clinical diagnosis of ischaemic stroke
• Stroke must cause a measureable
neurological deficit (NIHSS >4)
• Time of symptom onset is known
• Sufficient time in 3 hours therapeutic
window to assess and treat
• No clear contraindication to
thrombolysis.
Contraindications to Thrombolysis (1)
HISTORY
• Haemorrhagic retinopathy
• Known or suspected history of intracranial bleed
• HI or stroke within last 3/12
• Major surgery/trauma within last 3/12
• Peptic ulcer
• Recent puncture of a non-compressible blood vessel
• Recent (<10/7) traumatic CPR or childbirth
• Severe liver disease
• Neoplasm with increased bleeding risk
• Prior stroke with concomitant diabetes
Contraindications to Thrombolysis (2)
CURRENT
• Symmptoms suggestive of SAH
•Evidence of intracranial bleed on CT
• Seizure at onset of stroke
• SBP of >185mmHg or DBP >110mmHg
• Symptoms rapidly improving before rt-PA
• Anticoagulants (except warfarin if INR <1.4)
• Platelet count below 100x103
• Clinically mild stroke (NIHSS <4)
• Clinically severe stroke (NIHSS >25)
• Severe stroke as assessed on CT (>1/3 MCA territory;)
• Previous functional status (Rankin score 3 or more)
ACUTE
MANAGEMENT
IN HOSPITAL
Time is brain!
NINDS recommended targets for time
• Door to Doctor
10 minutes
• Access to Neurological expertise
15 minutes
• Door to CT completion
25 minutes
• Door to CT interpretation
45 minutes
• Door to treatment
60 minutes
• Admission to monitored bed
3 hours
Acute Management
Vitals:
A : Is the airway secure?
B : O2 saturation > 95%?
(put all patients on an oxygen mask)
C : BP? Too high or too low? Is patient in AF?
History:
- Symptom onset or time last seen normal
- Correlate times (alarms, work, drive time TV)
- Corroborate with any available witness
- Prodromal or previous symptoms/TIAs
- Exclude stroke mimics
***IS THE PATIENT A CANDIDATE FOR THROMBOLYSIS?***
Thrombolysis in the ED
• IDENTIFY POTENTIAL CANDIDATE
• IMMEDIATELY CONTACT STROKE PHYSICIAN
• Take bloods (FBC, U&Es, glucose, clotting)
• Acquire a 12-lead ECG
• IV access x 2 (preferably large gauge)
• Document observations every 15 minutes
• Check capillary BM
• Administer O2 at 2-10 L/min
• If BP consistently >185 SBP or >110 DBP - labetolol
• ORGANISE IMMEDIATE CT SCAN
Stroke Physician Assessment
• Examine patient and confirm diagnosis
• Discuss risks/benefits with patient/relatives
• Obtain informed consent
• Review and confirm inclusion/exclusion criteria
• Complete NIHSS and Rankin scores
• Obtain weight estimate
• Review blood results and CT images
• Calculate dose of rt-PA
- 0.9 mg/kg (max. 90mg)
- 10% dose stat over 1 min
- remaining 90% over 1 hour
• Patient admitted to Level 1 area
POST-THROMBOLYSIS
ASSESSMENT AND
MONITORING
Post Thrombolysis (1): The ‘DOs’
• Check observations:
- every 15 minutes for 2 hours
- every 30 minutes for 6 hours
- every 60 minutes for 16 hours
• NIHSS at 2 hrs, 24 hrs and 7 days ( or discharge)
• Maintain oxygenation
• Treat pyrexia aggressively
• Manage blood glucose actively
• Prompt swallowing assessment
• IV fluids if needed
• Nurse with head and trunk at 30 degrees in bed
Post Thrombolysis (2): The ‘DON’Ts’
For the first 24 hours (unless absolutely necessary):
•No urinary catheters
•No NG tubes
•No aspirin / dipyridamole / clopidogrel
•No heparin (not even prophylactic doses
•Avoid central venous and arterial lines
24 hours Post-Treatment
Likelihood of rt-PA complications reduced
Usual stroke aftercare resumes:
1. aspirin 300mg after repeat scan
2. NG tube if required
3. Investigations of stroke aetiology as indicated
4. Secondary prevention therapy
5.Begin normal rehabilitation
BP Management Post-Thrombolysis
Significant HTN post-treatment is
potentially hazardous due to haemorrhagic
transformation.
SBP >180 or DBP >105 on two occasions
over 5 minutes:
1.
2.
3.
4.
5.
6.
Labetolol 10-20mg IV stat
Repeated dose Labetolol can be used
Consider Labetolol infusion
GTN infusion (as per cardiac dosing)
Avoid Ca+ channel blockers
Na+ nitroprusside infusion on ITU
Neurological Deterioration Post Thrombolysis
ICH may be signalled by acute HTN,
headache, neurological deterioration,
and N&V.
Inform Stroke team immediately
Repeat CT head
Contact neurosurgeons if haemorrhage
- stop rt-PA infusion!
- check FBC and clotting
- Give FFP, cryoprecipitate, platelets
Treatment is usually conservative
BARRIERS TO
RAPID ACUTE
STROKE CARE
1. Patient inability to recognise stroke symptoms
- 40% of stroke patients cannot name a single sign or symptom or
stroke risk factor.
- 60% of patients would contact their GP or NHS Direct if having a
stroke
- 75% of stroke patients misinterpret their symptoms.
- 86% of patients believe that their symptoms are not serious enough
to seek urgent care.
2.
Just over half of GPs said they would refer someone with a suspected
stroke immediately.
3. Hospital physicians’ lack of experience with stroke thrombolysis and
therefore reluctance to ‘risk’ treatment.
4.
< 12% of hospitals have protocols in place with ambulance services for
the rapid referral of those with suspected stroke.
5.
< 50% of hospitals with acute stroke units have access to brain
scanning within three hours of admission to hospital.
UK thrombolysis use in research (IST-3)and practice
(SITS)