CVA, TIA - Brain Attack Flashcards
What is a stroke?
infarct of brain tissue d/t lack of blood flow to a certain part of the brain
complete blockage is caused by a clot or by a hemorrhage
decreased blood flow is caused by a stenosed occluded or ruptured blood vessel feeding the brain
Stroke: RFs
HTN High Cholesterol DM Smoking Obesity (esp central) Age Cocaine and methamphetamines ETOH (daily) Hispanics, Native Americans, Asian Americans, and Black Americans AFib Previous TIA or CVA
Stroke: Pathophysiology
when there is a blockage or hemorrhage in a certain blood vessel, that area of the brain becomes ischemic
neurologic metabolism is altered in 30s, metabolism stops in 2 min, and cell death occurs in 5 min
when tissue becomes ischemic the body responds by causing cytotoxic edema in the surrounding tissue making perfusion even more difficult, increasing ICP
Stroke: Prevention of CVA/TIA
- decrease BP
- decrease cholesterol
- well controlled blood sugar
- stop smoking
- anti-platelet aggregation meds (ASA, plavix)
- anticoagulant for Afib
- decrease alcohol use
- control obesity
- increase exercise
identify and tx asymptomatic carotid stenosis
- carotid bruits & screen w/ u/s and doppler
- tx w/ ASA or other platelet anti-aggregate meds, statins
- if stenosis found a carotid endarterectomy will be done to improve cerebral flow
cerebral aneurysms: monitor, or tx w/ balloons, stents, coils
prevent cardiogenic emboli w/ tx of Afib; ASA. coumadin, xarelto, pradaxa
TIA: Definition and Sx
brief episode of neuro dysfunction caused by focal or retinal ischemia w/ symptoms typically lasting less than 1 hour and w/o evidence of acute infarction
typically all symptoms resolve w/in 24 hours, no residual effects
most common occur in carotid and vertebrobasilar arteries
Sx: numbness, weakness, paralysis, slurred speech, dizziness, confusion, aphasia, double vision, loss of half of visual field (hemianopia), loss of vision in one eye (amaurosis fugax)
TIA and the Future
Recognition is critical in these patients b/c TIAs increase the risk of strokes:
- 1/3 have no more TIA’s
- 1/3 have more TIA’s
- 1/3 progress to CVA
may be caused by an unstable plaque that occludes distal tissue
may be caused by a microemboli temporarily blocking blood flow
Types of CVA’s
ischemic: interruption of blood supply
- 87% of strokes
- damage is done only from lack of blood
hemorrhagic: rupture of blood vessel of abnormal vascular structure
- 13% of all stokes
- damage is done d/t lack of blood and pressure from bleeding
Ischemic Strokes: Causes
- thrombosis: clot forming locally
- embolism: embolus from somewhere else in the body
- systemic hypoperufsion: -general decrease in blood supply
- venous thrombosis: could dislodge and travel
Ischemic Stroke: Thrombosis
- clot form w/in vessel of brain which cuts off blood supply beyond the location of the clot
- usually forms d/t atherosclerosis
- occurs when BP is the lowest, usually
most common cause of CVA in elderly and middle age
Ischemic Stroke: Embolic
blockage of artery by an arterial embolus, a traveling particle or debris in the arterial bloodstream originating elsewhere (can be blood clot, fat, air, cancer cells, or bacteria)
RF: Afib, rheumatic fever, open heart surgery, ortho surgery, endocarditis
source must be identified
tend to occur during day, during periods of activity
if embolus is septic, the infection may extend beyond the vessel wall, leads to abscess which may develop into an aneurysm
can occur at any age
Ischemic Stroke: Hypoperfusion
reduction in blood flow to all parts of the body
-commonly caused d/t HF from cardiac arrest or arrhythmias
reduction in blood flow is global so all parts of the brain is affected
blood flow to these areas does not stop, but is decreased to the point where brain damage can occur
Hemorrhagic Stroke: Intracerebral
bleeding w/in the brain cause by a rupture of a vessel
very poor prognosis
often occur w/ activity, rapid onset of symptoms
RF: HTN, aneurysms, trauma, anticoagulant meds, thrombolytic drugs, thrombocytopenia, tumors, AV malformations
Sx: loss of consciousness, worst HA ever, vomiting, decreased LOC
extent of sx depends on amount, location, and duration of bleeding
Hemorrhagic Strokes: SAH (subarachnoid hemorrhage)
bleeding into the cerebrospinal fluid space between the arachnoid and pia mater membranes on the surface of the brain
often caused by rupture of cerebral aneurysm, trauma, or cocaine
increased incidence w/ age and higher in women
“silent killer” as there are few warning signs
worst HA ever
poor prognosis
Expressive Aphasia
difficulty speaking or writing
Wernicke Aphasia
can’t understand, but can speak
Receptive Aphasia
difficulty understanding writing and spoken word
Apraxia
inability to carry out some motor pattern (drawing a figure, getting dressed) even when strength has returned, can also be speech apraxia
Unilateral Neglect
disorder of attn where client can’t integrate and use perceptions from the affected side oft he body causing that part to be ignored
Agnosia
inability to recognize one or more objects that were previously familiar by sight, touch, or hearing
Dysphagia
trouble swallowing
Dysarthria
trouble speaking, but can understand
Homonymous hemianopia
hemianopia: loos of half of visual field of 1 or both eyes
homonymous: same 1/2 in both eyes, e.g. loss of vision in nasal field of right eye and temporal field of left
Assessment Data for Stroke: Motor Fxn
no significant difference between ischemic and hemorrhagic
destruction of tissue is basis for dysfunction
motor fxn:
- mobility
- respiratory fxn
- swallowing and speech
- gag reflex
- self care abilities
Assessment Data for Stroke: Communication
communication (left hemisphere is dominant for language skills for right-handed people and most left-handed people)
- dysarthria: understanding is good, evaluate
- pronunciation, articulation, phonation
Assessment Data for Stroke: Spatial-Perceptual Problems
most likely for right-sided stroke
- incorrect perception of self and illness
- unilateral neglect (worsened by homonymous hemianopia, difficulty in judging distance)
- agnosia
- apraxia: inability to carry out learned sequential movements on command
Assessment Data for Stroke: Elimination
many issues related to inability to communicate needs and functional incontinence
most urinary problems are temporary (if only one hemisphere of brain is involved)
initially: frequency, urgency, and incontinence (bladder training is needed)
constipation: immobility, weak abdominal muscles, dehydration, decreased response to the defecation reflex
Assessment Data: Contralateral or Ipsilateral
Contralateral: opposite side of body
-lateral hemisphere damage results in sx on the right side of body and vice versa
Ipsilateral: same side
-damage to cranial nerves result in sx on the same side of body
Stroke Timeline
Head in CT:
door to scanner in 20 min
read CT w/in 45min
Stroke: P/I in Acute Phase
- avoid hypoxia, hypercapnia (O2 tx, maintain airway)
- labs (PT/INR, aPTT, CBCC, Electrolytes, CMP, Troponin)
- ECG: 12-lead
Ischemic Stroke: Tx
tPA to reestablish blood flow thru blocked artery:
- must be given w/in 3-4.5 hrs of the onset of signs of ischemic stroke
- BP should be <185/110 at time of tx (need to have higher perfusion in brain to get blood flow to space that isn’t getting any blood, banking on collateral blood flow, need high BP to overcome ICP)
before tPA, insert multiple IV sites, foley, and NG tube
need to check bleeding time (PT, aPTT to r/o coagulation disorders, ask about hx of GI bleed)
NO anticoagulants for first 24hrs after tPA
risk of death w/in next 7-10 days, increased risk of hemorrhage, monitor for increased ICP
mechanical removal of clot via femoral artery to remove or insert stent to open blockage
if not a candidate for tPA, use IV heparin (aPTT should be 2-3x the normal (24-35s)
- transition to PO anticoagulant (Warfarin, Coumadin)
- monitor PT/INR (2-3x normal)
- PT: 10-14s
- *INR: 1-2
- Platelet inhibitors: ASA (ask about hx of gastritis), Plavix, Ticlid
Hemorrhagic Stroke: Tx
no anticoagulant manage BP (normal to high <160mmHg)
if aneurysm, than may have surgery
-clipping or coiling
monitor for seizures - 10-15% experience seizure w/in first 24 hours
-tx w/ anti-seizure meds
General Care of any type of CVA
adequate hydration: 1500-2000ml/day but avoid cerebral edema
- avoid hypotonic IV solution (D5W), can cause increased cerebral edema
- tx edema w/ diuretics (mannitol for increased ICP, furosemide)
- monitor urine output
monitor for increased ICP (GCS score)
- associated more w/ hemorrhagic CVA
- peaks at 72 hours may cause brain herniation
- prevent by: raising HOB, head and neck properly aligned, avoid hip flexion, coughing
- monitor for hyperthermia (tx w/ acetaminophen), causes increase cerebral metabolism
Long Term Tx (usually 12-24 hours till stable)
continue VS and I&Os
Neuro checks to determine increased ICP
monitor for HTN and pulmonary congestion
musculoskeletal - PROM to affected side 2-3x/day, TEDs, SCDs
eval by PT ASAP
offer bedpan/commode q2hrs to start bladder retraining
monitor for skin breakdown (d/t immobility, decreased nutrition, incontinence, decreased sensation and circulation)
