Week 3 Acute Care CVA Flashcards
Infarction: tissue death (necrosis) due to inadequate blood supply to the affected area
Typically evident, but not always, on neuroimaging
(Not all/All) strokes are symptomatic
Why so important; why a whole pres. On this? (>50% statistic). If you work in or have a clinical in AC, you will almost certainly see some pts with acute stroke. Good news, treatable!
Not all
~ 80% suffer (ischemic/hemorrhagic), ~20% (ischemic/hemorrhagic) stroke
(Ischemic/Hemorrhagic) stroke – weakening of the blood vessel wall, and with high BP it will burst that weakened part of the wall and blood will distribute wherever it goes. These don’t follow a typical arterial presentation. The blood will travel in a way of where the path of least resistance is. It only represents 15-20% of the stroke population.
(Ischemic/Hemorrhagic) stroke – The more classic form of a stroke where some sort of clot forms within the brain and then the blood can’t physically get through and the tissues where the blood should be going start to die fairly quickly. This is about 80-90% of the stroke population.
Every minute counts post stroke because as time passes the more the tissue dies and the less opportunity that tissue has to recover.
ischemic; hemorrhagic; Hemorrhagic; Ischemic
Even before we consider stroke ——- can we prevent one from ever happening????
80% of stroke (can be/can’t be) prevented – National Stroke Association
Atrial Fibrillation (irregular heartbeat) - ↑ stroke risk 5 x’s
Decreasing (SBP/DBP) by 5-6 mmHg has been shown to decrease stroke risk by up to 40%
The incidence of stroke (halves/doubles) with every decade of life after age 55
There are hypothesized to be many alleles with small effect sizes associated with multifactorial strokes (Goodman and Fuller)
Heart disease and patent foramen ovale are both risk factors for stroke. Numerous other pathologies of the cardiovascular system would also qualify, but these two are more prominent so worth mentioning. They don’t neatly fit into either category.
Causes of CHF are multi-factorial and can be related to lifestyle, or more idiopathic.
http: //www.lifelinescreening.com/Partners/BD-Landing-Pages/Business-Partners/partner-pages/Health-Insurance/Carotid-Artery-Disease (last accessed 1/13/2018)
High blood pressure (decreases/increases) risk of stroke!!
Sickle cell – blood properties themselves are sick and maintain its integrity and carry oxygen where it needs to go to.
Whether inpatient or outpatient, can potentially save a life by discussing modifiable risk factors with pts.
can be; DBP; doubles; increases;
MANY FACTORS ARE SILENT!
- CAD often no warning signs or symptoms of carotid artery disease (plaque)
- A-fib not everybody with atrial fibrillation experiences symptoms, these warning signs may indicate heart issues: Heart palpitations (sudden pounding, fluttering, or a racing feeling in the chest), Lack of energy, Lightheadedness, Confusion, Chest discomfort, Shortness of breath, even at rest
[Post acute a-fib monitoring via CardioKey, CardioNet, LINQ, holter]
- High cholesterol and CRP Warning signs - none
- DM – may live for years w/o symptoms
Total Cholesterol (Source: American Heart Association)
Less than 200 mg/dL - Desirable level that puts you at lower risk for coronary heart disease. A cholesterol level of 200 mg/dL or higher raises your risk.
200 to 239 mg/dL - Borderline high.
240 mg/dL and above - High blood cholesterol. A person with this level has more than twice the risk of coronary heart disease as someone whose cholesterol is below 200 mg/dL.
LDL (Bad) Cholesterol Level - Less than 100mg/dL is optimal (Source: National Heart, Lung, and Blood Institute )
HDL (Good) Cholesterol Level - 60 mg/dL and higher is considered protective against heart disease (Source: NHLBI)
C-reactive Protein Screening
- It’s now believed that high CRP levels are associated with cardiovascular disease, stroke, coronary heart disease, peripheral arterial disease, and type 2 diabetes. CRP is part of the immune system and is released into the blood when the body responds to injury or infection. Within 24 to 48 hours of an infection or trauma, CRP levels can increase 1000-fold. The high-sensitivity C-reactive Protein (hs-CRP) screening measures CRP levels in the blood. In 2003, the American Heart Association and the Centers for Disease Control and Prevention announced that CRP >3 mg/L indicates a high risk for cardiovascular disease, even if cholesterol levels are low.
Have to take BP as PTs especially on an initial visit.
Got it
Prevention (education):
—Only about 60% of Americans can recognize even one warning sign, and only 55% can identify one stroke symptom.
- **This was updated a few years back to be BE-FAST Balance, Eyes, Face, Arm, Speech, Time
https: //www.ahajournals.org/doi/10.1161/STROKEAHA.116.015169
FAST turned into BEFAST. BEFAST can be used as a pt education tool to teach pts the signs and symptoms of a stroke.
What is the individual words for the acronym BEFAST?
If you feel something is funny, try to get to the hospital ASAP.
B - Balance E - Eyes F - Face A - Arms S - Speech T - Time
Got it
Got it
General Clinical Presentation of a stroke – Hyperacute stage
(Chronic/Sudden) weakness or numbness of the face, arm, or leg
(Chronic/Sudden) loss of vision, particularly in one eye
(Chronic/Sudden) difficulty speaking or understanding speech
(Chronic/Sudden) severe headache with no known cause
Unexplained dizziness, unsteadiness, or falls
What do all these features have in common?
Acute/sudden change – usually indicates (neurological/vascular) problem compared to gradual/slower progression of symptoms
Not a comprehensive list nor do all these features need to be present
When you have an acute sudden attack that happens within seconds/minutes it is typically suggestive of a vascular problem.
In strokes the blood vessel has either infarcted or there is a clot within the blood and the blood can’t get through or the weakening of the blood vessel has become too much and the blood is bursting out. That happens in seconds/minutes.
In strokes, it doesn’t build up over weeks, rather it takes place relatively quickly.
Sudden; sudden; sudden; sudden; vascular
If you are experiencing these symptoms you have to get to the hospital ASAP because every second, minute, hour is important to save as much (heart/brain) tissue as possible. Once that brain tissue dies, we are under the impression that it is gone forever.
brain
FIRST, vital signs and serum glucose. Establish LKN (last known normal). Examine patient (NIHSS). Then HCT without contrast is always first imaging test.
-why CT shows hemorrhage vs infarct (cellular level)? CT more sensitive to fluid/water changes compared to tissue death
CT scan is 1) fastest, 2) most convenient, and 3) most widely available test to use for diagnosis of stroke
the primary reason to use CT is related to the point listed above. If the HCT shows a hemorrhage, then IV tPA is not appropriate and we begin (usually) aggressive BP management.
If it shows an infarct, then the stroke is likely > 4.5 hours old and the patient is outside the window for IV tPA, however may be appropriate for thrombectomy.
If there is no stroke and the patient is medically appropriate for tPA, then we look at the NIHSS -> generally, scores that indicate moderate deficits (5-15 ish) on the NIHSS are considered candidate for tPA.
MRI is then used to confirm presence of an occlusion and the patient is evaluated for appropriateness of thrombectomy
LATER: all the others. Angiogram: uses x-ray techniques such as fluoroscopy
All patients with suspected acute ischemic stroke who arrive within 6 hours and are potentially eligible for endovascular thrombectomy should undergo immediate brain imaging with non-contrast CT and CT angiography (CTA) without delay, from arch-to-vertex including the extra- and intra-cranial circulation, to identify large vessel occlusions eligible for endovascular thrombectomy [Evidence Level A].
Angio-”related to blood vessels”
HCT scan – a bunch of xrays taken all at once to create a 3D representation of the brain.
CTA – Look at the blood flow of the brain
Carotid US – Picture on this slide. Done to look for clots.
TTE/TEE – Looking for clot like formations in the heart itself.
To determine if this person did have a stroke, imaging is going to help with that.
Got it
Imaging: Head CT
CT scans may appear normal with acute embolic (ischemic) stroke
However, hemorrhagic strokes (will be/will not be) seen - Can be seen up to 5 days following insult
Displacement of brain structures such as ventricles can sometimes be seen early in a large infarct
CT scans of ischemic stroke will eventually reveal area of decreased density and loss of grey/white matter differentiation associated with cerebral edema
60% of infarcts are seen within 3-6 hrs and virtually all are seen in 24 hours.
If someone gets a CT scan and it is normal and there’s no evidence of abnormality it is likely an (death/infarct).
will be; infarct
Differentiation of Stroke Type
(Hemorrhagic/Ischemic) strokes do not follow an artery distribution, and as such, symptoms may not follow typical (artery) pattern
Vomiting, a severe headache, seizures, and/or impaired consciousness are symptoms that may differentiate hemorrhagic from ischemic strokes
Important to determine hemorrhagic vs ischemic for medical management (HCT!)
With a hemorrhagic stroke you will see displacement of certain structures
The fluid in (hemorrhagic/ischemic) strokes may have impacted structures responsible for autonomic regulation of the brainstem which is why you will get vomiting, headaches, etc.
In (hemorrhagic/ischemic) strokes you will feel the facial droop, arm weakness, etc.
Hemorrhagic; hemorrhagic; ischemic;
The less amount of bleeding, the (worse/better)
Hemorrhages tend to do functionally a little bit (worse/better) than ischemic strokes because the tissues don’t necessarily die. The blood gets reabsorbed into the body versus causing true ischemia to brain tissue.
Hemorrhages on a macroscale are more severe early on, but they tend to do (worse/better), while infarcts are less severe early on but they tend to do (worse/better)
better; better; better; worse
If you draw a line through the middle of the skull you can see it is not directly straight up and down, it is shifted over. There is (less/more) volume of fluid than the brain is used to so tissue has to move to accommodate it and it will eventually end up disrupting function. The white stuff is blood.
more
Subarachnoid Hemorrhage (SAH)
(Chronic/Abrupt) onset usually from burst aneurysm/AVM
Occurs typically in (younger/older) adults
(Posterior/Anterior) communicating artery is common site
Severe headache, loss of consciousness (LOC)
High fatality rate (50%)
(Decreased/Increased) risk of vasospasm
With SAH, we worry about risk of vasospasm 7-10 days following symptom onset > risk of hypoperfusion, you may see acute fluctuations in a person’s exam (facial droop, language deficits) which could indicate acute spasm, and would necessitate need to return to (prone/supine) position.
Abrupt; younger; Anterior; Increased; supine
The volume of fluid is so small by the arrow that you don’t see a ton of displacement by the ventricles. This might be a smaller hemorrhage and if that person can survive the first 7-10 days so to speak, they’ll likely do very well.
Got it
Hemorrhagic Conversion
Ischemic infarct may convert into a hemorrhagic lesion
Thrombi (clot in the brain) can migrate, lyse and reperfuse into an ischemic area, leading to small hemorrhages
Damaged capillaries and small blood vessels no longer maintain their integrity
Conversions more common in (small/large) infarcts such as an occluded MCA – there’s so much pressure in the vessel that the smaller capillaries and blood vessels can’t maintain it.
A risk of tPA - tPA is a clot buster and it is medication that dissolves the clot. But when that happens the blood is on the thinner side and can give you a hemorrhagic conversion
The blood itself is not being managed enough to the point where it can hold the integrity and you get these microhemorrhages. The stroke team want to make sure once the clot is there that they do everything to get rid of it to prevent secondary complications.
large;
Aneurysm vs. AVM
Aneurysm:
Congenital or d/t long standing HTN (Strengthened/Weakened) area of vessel Balloons out Risk of embolic clot formation Risk of rupture/bleed
Arterial-Venous Malformation:
Congenital malformation of an arterial/venous bed
(Low/High) risk of bleed
Surgical management either pre/post bleed
12% cause CNS signs, others are benign
Imaging: cerebral angiography
Aneurysm & AVMs can both lead to hemorrhages.
An (aneurysm/AVM) is dilation of the blood vessels. It hasn’t ruptured yet, think of it as a little pimple on the blood vessel that increases the risk of it rupturing.
(Aneurysm/AVM) - the blood isn’t getting to and from where it should and the disturbance of the architecture of the plumbing of the brain can increase risks for hemorrhages.
Weakened; High; aneurysm; AVM
Won’t be tested on this
Got it
SAH Outcome
May have (worse/better) functional outcome than ischemic CVA - Greater functional gains
(Low/High) degree of cognitive impairments - Usually end up physically independent
(Low/High) fatiguability
Physically they do well, but cognitively they won’t do so well.
better; high; high
Look at how the hemorrhage has evolved, that is not a good sign. Need to physically (increase/reduce) the BP so they don’t have as much blood pumping through the brain making this worse.
reduce
Acute Phase Management
Special consideration - MAP (Mean Arterial Pressure)
Definition: average arterial pressure throughout one cardiac cycle, systole, and diastole
MAP= (2(DBP) + SBP)/3
Ischemic typical MAP goal <140 (UPHS)
BP “should not be lowered unless it is as high as 230/120 mmHg. The goal is not to try to normalize the pressure, but to bring it down from dangerously high levels…cerebral perfusion is the main concern” (Goodman & Fuller 2009)
Medical management of cardiac function may include permissive HTN for ~10 days post stroke - Blood pressure will be resting (low/high). If there is a physical block within the blood vessel. If you have higher pressure it is going to keep all that blood moving to allow blood to get to those parts that are dying as best as they can.
Chart review: check orders! (and ask RN)
Mean arterial pressure is significant because it measures the pressure necessary for adequate perfusion of the organs of the body. It is considered by many to be a better indication of perfusion than systolic blood pressure.
Too high: (>100) - too much stress on organs
Too low – risk of organ death
Good – emphasis of BP parameters for stroke patients – discuss both goal BP’s and cutoff BP’s. May be in POC and not necessarily in an order. There may be variation from MD to MD (or between facilities), so it’s important for therapists to independently consider them. Neurologist may be providing the order in your setting. What is the evidence for the SBP/DBP and duration limit? (Unclear?)
BP goals fluctuate a lot. The general rule is < 220/110 or MAP <140 for ischemia, <180/105 for ischemic stroke with HT, and < 160/90 for hemorrhage. Most of the time, it’s more about big changes in the moment (i.e. if a person starts at 200/100, and then upon sitting up is light-headed and BP is 160/80, then the significant drop in BP is more concerning than the high starting BP
The goal is to manage pressure in and out of the brain so that way you don’t worsen someone’s function or their tissue integrity. Want just enough blood to the brain so the organs can have enough oxygen to survive.
high;
Monitor warnings of (increased/decreased) ICP.
GOAL of NICU IS PREVENT (PRIMARY/SECONDARY) BRAIN DAMAGE.
Goal of most of these: manage cerebral perfusion pressure and ICP
AC can be reversed quickly with fresh frozen plasma; vitamin K takes 12-24hrs
Preventing seizure: done with medication
EVD = External Ventricular Drain - can both monitor ICP and remove fluid device placed by neurosurgerythatrelieves elevated intracranial pressure(blood or CSF) andhydrocephaluswhen thenormal flowofcerebrospinal fluid aroundthebrainisobstructed (or there’s blood in the ventricles)
Ventriculostomy: the surgery itself > EVD is usually placed on the R side of the brain to avoid language centers (occasionally will be placed on L for various extenuating circumstances, or confirmed that the patient is L handed and language center is more likely on the right)
Monitor and manage ICP: Thenormal ICPis 7-15 mmHg. There is no defined set point at which treatment for intracranial hypertension should be initiated, but levels above 20 mmHg are usually treated. However it is more important to maintain an adequate cerebral perfusion pressure.
Avoid Vasospasm > risk for vasospasm is highest days 7-10 post bleed. Look for elevated velocities on TCDs or vessel narrowing on CTA or MRA of brain. With TCDs, the Lindegaard ratio (aka LR is a ratio of MCA velocity to terminal ICA velocity) helps to 1) minimalize interrater reliability, and 2) indicate true vasospasm. Scores ~1.5-3 indicate minimal spasm, 3-6 is moderate spasm, and >6 is severe spasm with risk for ischemia and hypoperfusion
Medical/Surgical: Ventilate, HOB position, 3% NaCl (hypertonic sodium chloride – pulls out fluid, monitor HTN), Mannitol (diuretic), Ventriculostomy, CSF diversion, Phenobarbital Coma, &/or decompression.
Intracranial Pressure Monitoring @ http://emedicine.medscape.com/article/1829950-overview?src=emailthis#a5 (last accessed 1/13/2018)
Communication with Megan Moyer at megan.moyer@uphs.upenn.edu on 12/17/2015
If someone has a hemorrhage there is too much pressure in the brain so need to reduce the pressure, but make sure it isn’t too low.
increased; SECONDARY;
Intracranial Pressure (ICP)
Intracranial pressure (ICP) is a resultant of the pressure applied by the components within an inflexible and rigid skull (Kawoos et. al, 2015)
Signs of increased ICP? Headache. Blurred vision. Feeling (more/less) alert than usual. Vomiting. Changes in your behavior. Weakness or problems with moving or talking. Lack of energy or sleepiness.
If someone has a hemorrhage there is too much fluid volume in a fixed rigid skull and then what happens is all of the signs of the increased ICP.
Greater than 20 mmHG is considered too high for ICP .
less;
Perfusion Goals
Cerebral Perfusion Pressure (CPP) = MAP – ICP
CPP 50-70 mmHg to avoid cerebral ischemia and hyperaemia -
Important with driving oxygen to brain tissue!
Too (low/high)? Too much blood flow and edema can worsen
Too (low/high)? Risk for ischemia
ICP less than 20 mmHg to maintain CPP, avoid brain herniation
- ↑ ICP, ↓ outcomes
↑ ICP, carries a mortality rate of 20%
CPP is the pressure gradient acting across the cerebrovascular bed and, therefore, a major factor in determining cerebral blood flow (CBF).
Normal ICP 7-15mmHg
CPP (Cerebral Perfusion Pressure) = mean arterial blood pressure (MAP) - mean intracranial pressure (MIC)
CBF is kept constant in spite of wide variation in CPP and MAP by autoregulation.
CBF normal = 50 ml/100g/min (remember: below 20 = neuronal functioning impaired. <10, neuronal death (infarction) occurs
CVR = Cerebral Vascular Resistance
Hyperaemia: shunting of blood to other tissues
Intracranial Pressure Monitoring @ http://emedicine.medscape.com/article/1829950-overview?src=emailthis#a5 (last accessed 1/13/2018)
Communication with Megan Moyer at megan.moyer@uphs.upenn.edu on 12/17/2015
The goal with stroke management is to keep enough pressure in the brain to provide oxygen but not too little where you get ischemia.
high; low; less than