IC6 Acute Ischemic Stroke Flashcards
Which thrombolytic is used in AIS?
Alteplase
- Dosed by body weight, administered as an infusion (10% as b0olus over 1 minute, 90% as infusion over 1h)
Why is follow up and monitoring important when given thrombolytic?
Monitor BP control and bleeding processes to avoid intracranial hemorrhage (due to hemorrhagic conversion - ischemic stroke to hemorrhagic stroke)
*Thrombolytics are HAM
What are some inclusion criteria to using Alteplase in AIS?
Inclusion criteria:
- Clinical diagnosis of AIS
- Treatment must be started within 3-4.5h of AIS onset
- CT scan consistent with AIS (NOT hemorrhagic stroke)
BP must be less than 185/110 to be eligible for tPA
What are some exclusion criteria to using Alteplase in AIS?
- onset >4.5h
- CT scan with intracranial hemorrhage
- seizure at onset of stroke
- improving symptoms
- previous stroke (3m), major surgery (14d), significant bleed (21d)
- SBP >185 or DBP >110 - due to risk of hemorrhagic conversion
- coagulopathy
- anticoagulant use prior to admission
- Age >80y
- Severe stroke: NIHSS >25
- Severe stroke: evidence of more than 1/3 MCA territory infarct on initial imaging
- Subacute bacterial endocarditis
- Post MI pericarditis
- Pregnancy (not CI)
Antithrombotics must be delayed _____ after Alteplase
24h after Alteplase
Investigations used for stroke
- CT scan - 5-15min, exclude bleeds (able to differentiate hemorrhagic and ischemic stroke)
- MRI scan - 45min-2h, able to pick up smaller structures such as new infarcts
*US not used as it is more useful for gross structure rather than bleeds/clots/infarcts
*US might be able to evaluate carotid vessels in the neck, check for atherosclerosis
What is the most common known stroke etiology?
Small-vessel disease/Penetrating artery disease
Other known etiology include:
- large-artery atherosclerosis
- cardioembolic stroke (AF most common)
What is trasient ischemic attack (TIA)?
The syndrome of arterial ischemia with transient symptoms (<24 hours) and without evidence of infarction is a transient ischemic attack (TIA).
What is the NIHSS score used for?
NIHSS score is a neurological examination, describes the diabilities resulting from stroke.
NIHSS score evaluates the effect of acute cerebral infarct on various functions (determines where the impact of the infarct is in the brain)
E.g., loss of consciousness, visual, motor arm
NIHSS scoring
What score constitutes a minor stroke?
15 items (mNIHSS: 11 items)
Minor stroke: NIHSS 0-3
*Generally =<5 means mild stroke symptoms (not eligible for r-tPA)
What is the ABCD2 score used for?
Estimate risk of ischemic stroke in the first 2 days after transient ischemic stroke (TIA)
What are the criteria in ABCD2 score?
Age
- > =60y: 1 point
- <60y: 0 point
BP elevation
- Systolic >=140 OR Diastolic >= 90 : 1 point
- Systolic <140 AND Diastolic <90 : 0 point
Clinical features
- Unilateral weakness: 2 points
- Isolated speech disturbance: 1 point
- Other: 0 point
Duration of TIA symptoms
- > =60min: 2 points
- 10-59min: 1 point
- <10min: 0 point
Diabetes
- Present: 1 point
- Absent: 0 point
ABCD2 scoring
What score constitutes high risk TIA?
ABCD2 score >=4
Stroke treatment algorithm
Patient has new-onset AIS, what should be considered first?
CT scan - determine if ischemic or hemorrhagic
Consider if patient is eligible for r-tPA
- Eligible if within 3-4.5h of onset
- Not eligible if beyond 4.5h
- Not eligible if mild stroke symptoms NIHSS =<5 as risks outweighs benefits
- Not eligible if severe stroke NIHSS >25
- Only consider mod-severe stroke (>5-25)
Stroke treatment algorithm
Why pt with NIHSS =<5 do not require rTPA?
People with NIHSS 5 and below are considered to have almost no major impairments to their daily ability to function. Thus, there would not be a need to thrombolyse them, since the goal of thrombolysis is to quickly reperfuse, in an attempt to limit the permanent damage to brain tissue and the corresponding disability.
