Thrombotic Diseases Flashcards
Define stroke
/Is a neurological deficit of cerebrovascular cause that persists beyond 24 hours or interrupted by death within 24 hours
When does stroke occur
when there is a rapid death of brain tissue due to a disturbance in blood supply
What is a major differentiating factor between a stroke and a TIA
Time frame - 24 hours
Stroke beyond 24hrs
Tia resolved within 24 hrs
Risk factors for stroke
Inactivity Previous stroke and tia Obesity/unhealthy etc Heart disease / high Bp Smoking Diabetes Age/ family history Oral contraception
What are the carotid arteries
Anterior supply for front and middle regions of brain
What are vertebral arteries
Posterior supply for brain stem and rear regions of brain
What are the 2 types of stroke
Ischamic
Haemorrhagic
Subtypes of ischaemic stroke?
- thrombosis
- embolism
- atrial fibrillation
- endocarditis
What is thrombosis cause ischaemic stroke?
Associated with the large and small arteries - carotid, vertebral, basilar
Damages caused by an atherosclerotic plaque rupture leading to thrombosis, this interrupts the blood supply and then nutrients such as oxygen and glucose cannot get to the neurons. There is a rapid death of brain tissue leading to loss of function
What is the embolism cause of ischaemic stroke ?
Caused by conditions that form clots in the left ventricle of the heart such as a heart attack or congestive heart failure.
The heart is the most common source of embolism to the brain so then these clots break off and go to the brain from upstream arteries
It is basically as a result of a low ejection fraction in the heart in these conditions which activate a clotting cascade and therefore clot —> embolism
Most common type of stroke
Ischaemic
What is the atrial fibrillation cause of ischaemic stroke?
During atrial fib -the left atrium is less effective in the ejection of blood which then lead to blood stasis in the left atrial Appendage which leads to clots and therefore the Emboli can break off and cause a stroke in the brain
What is the endocarditis cause of stroke?
There can be fungal or bacterial growth in the heart valves which then form clumps or vegetation which can break off into emboli and travel to the brain
2 types of haemorrhagic stroke?
Intracerebral
Subarachnoid
What is intracerebral stroke and it’s cause?
Bleeding Within brain - due to hypertension, trauma, bleeding disorders or vascular defects
Arteriovenous malformation - the feeder artery to NIDUS lead to collection vein
There is a highBP in AVM which causes rupture and bleeding - causes haematoma which can compress, rupture and damage neurone - irreversible damage
What is subarachnoid stroke and risk factors
On surface of brain - mainly due to aneurism rupture mainly occurring in circle of Willis
Risk factors are smoking,alcohol, hypertension, genetics, drug abuse and drugs eg anticoagulants
How does subarachnoid stroke damage the brain?
- compression of tissue From expanding haematoma
there is also toxic affects due to free iron
there’s also interruption of blood supply to neutrons
2 types of aneurism?
Saccular (berry) - protrude our of artery
Fusiform- elongates within artery
Which area is highly susceptible for aneurism in the brain stem?
Subarachnoid space
Define transient ischaemic attack
Temporary blockage of the blood supply due to small blood clot. It can be overcome within 24 hours.
It’s occur repeatedly or in multiple regions of the brain. And it can lead to a major stroke I’m so we need to treat it as soon as possible to prevent this
How do we assess the risk of a stroke following a patient having a TIA?
ABCD2 model
Describe ABCD2 model
- age - 60 or over 1 point
- blood pressure on presentation 140/90 or higher -1 point
- clinical features eg
If have unilateral weakness 2 points
Speech disturbance but no weakness-1 point - duration of symptoms
30-59 min 1 point
60 min or over 2 points
Presence of diabetes is 1 point
According to ABCD2- what score would place the patient at high risk?
A score of 4 or more (but beware that in crescendo stroke -(2 or more TIA/ week) -would be higher risk regardless of the score
If a patient has ABCD2 score of 4 or more what action is taken
High risk of having a major stroke so
300 mg aspirin daily immediately
Specialist assessment within 24 hrs of TIA symptoms
What are limitations of ABCD2 model
It cannot be used in people who have had multiple recurrent TIAS, or those on anticoagulants
How can we recognise stroke?
FAST
F- face- is their face dropping/can they smile/ eye drop
A- arms - can the lift both arms up and keep them there?
S- speech- can they speak clearly, slurred? Can they understand what you say?
T- time to call 999 if see any features
What scale is used to recognise stroke in A&E
Rosier scale
Action taken with an ABCD2 score of less than 4?
Specialist assessment within a week of onset, refer to brain Imaging if need
What are the Symptoms of stroke and how do these link to areas of the brain affected?
- numbness or face arm leg on one side (sensory cortex)
- weakness of face arm leg on one side (motor cortex)
- loss of coordination and balance- cerebellum
- loss of consciousness
- worse headache of life
- double vision/blurred - occipital lobe
- slurred speech or loss of speech- broad or wernickes area
What are the aims of pharmacological treatment in stroke
- To prevent further strokes
- Prevent further neuronal loss neuro protection
- Repair or replace damaged neurons called neuro restoration
All done within 4.5 hrs
What is the main drug given within 4.5 hrs ofischaemic stroke
Thrombolytic agent - tissue plasminogen activator (tPA) eg alteplase 900 microgram/kg/hr (IV)
What does tissue plasminogen activator do?
Activated plasminogen into plasmin which binds to the clot and dissolved it so thrombus broken down into proteolytic degradation products
What is overall pharmacological treatment of ischaemic stroke ? - INITIAL
- alteplase 900 microgram/kg/hr in specialist stroke centre or trained staff
- aspirin 300 mg OD for 2 weeks - oral or via recital/enteral tube IF- dysphagia, history of Dyspepsia/ given a PPI
if intolerance to aspirin then can give clopidogrel 75 mg OD. But if clopidogrel contraindicated or not tolerated - give MR dipyridamole in Combo with aspirin
also give statins, antihypertnesives etc and surgery to remove plaque (endarterectomy) or stent insertion in angioplasty
Long term pharmacological management of stroke (ischaemic)?
Long term clopidogrel 75 mg OD
If patient has:
- TIA
- ischaemic stroke but clopidogrel contraindicated- then use
MR dipyridamole 200 mg BD in combo with aspirin 75 mg OD
What is the Pharmacological treatment for haemorrhagic stroke?
Removal or clip of aneurism
- reverse any anti coagulants
- start on anti hypertensive
Can also do surgieries to-
- remove blood/haematoma
- remove CSF - hydrocephalus treatment
What is the non pharmacological long term management of stroke?
Restoration of functions eg physio, speech and language therapy, OT, psychologist
Also learning new skills
Adapting to some limitations caused by stroke eg smaller meals to avoid choking, physical changes to home, In continence pads, communications and mobility aids
Support networks - patience, positivity
What is DVT
A blood clot occurring in the deep veins of the legs
There is no movement which reduces bloodflow in the veins leading to an accumulation of platelets and plasma proteins which cause clotting
Dislodged clots can travel to the heart and then into the lungs which causes a pulmonary embolism
Causes of DVT?
- inactivity eg immobile for long time
- hospital stays
- blood vessel damage eg injury - vasculitis/varicose vein
- medical conditions
- genetics eg thrombophilia/Hughes syndrome
- pregnancy
- combined contraceptive pills
Sedentary lifestyle, age, obesity, dehydration
Symptoms of DVT
Sometimes asymptomatic
- pain, tenderness swelling in area - 1 leg
Heavy pain
Warm skin in area
Redness at back of leg below knee
Swelling and fluid congestion as blood not moving
If untreated can lead to PE leading to breathlessness, chest pain, collapse
How is DVT diagnoses?
Blood test for d- dimer levels
D dimers are usually released into the plasma during a clot as a result of a cross linked fibrin mesh
Also use ultrasound and venogram
Treatments for DVT?
Anticoagulants to prevent clots. Getting bigger
- Heparin - usually low mwt or unfractionated- inhibits thrombin- IV of s/c
- Warfarin sodium - oral tab- start at same time as heparin - but not used in pregnancy
(Also use apixaban and rivaroxaban) - Compression stockings
- Inferior vena cava filters when anticoagulants not suitable
And exercise eg walking, raising legs when sitting d
