Exam 4 (Critical neuro, organ transplants, and pituitary/adrenal) Flashcards
TTrue or false
Transient ischemic attacks (TIA) or a reversible ischemic neurologic deficit (RIND) may be warning signs of impending ischemic stroke.
True
TIA vs. RIND
**Both warning signs cause transient focal neurologic dysfunction resulting from a brief interruption in cerebral blood flow from cerebral vasospasm or arterial hypertension.
• A TIA lasts a few minutes to less than 24 hours and RIND lasts longer than 24 hours.
• Both TIAs and RINDs may damage the brain tissue with repeated insults.
True or false
A stroke is caused by a change in the normal blood supply to the brain.
True
True or false
Like that of many health problems, the causes of stroke are likely a combination of genetic and environmental risk factors.
True
Describe an occlusive stroke
In an occlusive stroke, arterial blockage or narrowing cause ischemia in the brain tissue ultimately leading to infarction of neurons in the involved area of the brain.
True or false
Most strokes are ischemic, caused by the occlusion of a cerebral artery by either a thrombus or an embolus.
True
Describe a hemmorhagic stroke
Hemorrhagic stroke involves bleeding within or around the brain.
• Intracerebral hemorrhage describes bleeding into the brain tissue generally resulting from severe hypertension.
True or false
Document the history of the stroke’s onset, as ischemic strokes often occur during sleep, whereas hemorrhagic strokes tend to occur during activity.
True
True or false
For patients having occlusive strokes, the standard of practice is to start two IV lines with nondextrose, isotonic saline.
False,
For patients having ischemic strokes, the standard of practice is to start two IV lines with nondextrose, isotonic saline.
What are two main treatments for patients with an acute ischemic stroke
The two major treatment modalities for patients with acute ischemic stroke include fibrinolytic therapy and endovascular interventions.
What is the most important factor in deciding to give rtPA?
The most important factor in whether or not to give rtPA is the time last seen normal (LSN).
- **The standard window for eligibility is 3 hours from time LSN.
- **In 2009, the American Stroke Association recommended an expanded time interval from 3 to 4.5 hours for patients unless they fall into the categories of age older than 80, anticoagulation with an international normalized ratio less than or equal to 1.7, baseline National Institutes of Health Stroke Scale greater than 25, or history of both stroke and diabetes.
What is an aneurysm?
- An aneurysm is an abnormal ballooning or blister along a normal artery.
- A congenital aneurysm is a defect in the media and elastica of the vessel wall.
- A dissecting aneurysm may occur following trauma or from plaque formation.
Diagnosing a stroke
- Clinical history and presentation usually are sufficient to diagnose a stroke.
- Computed tomography and angiography assist in the differential diagnosis.
True or false
Patients are most at risk for the serious complication of increased ICP resulting from edema during the first 72 hours after onset of the stroke.
True
Traumatic brain injury: open vs closed
- Primary brain damage occurs at the time of injury and results from the physical stress within the brain tissue caused by open or closed trauma.
- Open head injury occurs with a skull fracture or piercing by a penetrating object.
- A closed head injury is the result of blunt trauma, is more serious, and the damage to brain tissue depends on the degree and mechanisms of injury.
What are common signs of a TBI
The most common responses are hypotension, hypoxia, ischemia, and edema.
True or false
Increased ICP is the leading cause of death in patients hospitalized with brain injury.
True
What is cushings triad?
Cushing’s triad, a classic yet late sign of increased ICP, is manifested by severe hypertension with a widened pulse pressure and bradycardia.
What is uncal herniation?
Uncal herniation, shifting of one or both areas of the temporal lobe, is one of the most clinically significant changes because it is life threatening.
Brain abcess
A brain abscess is a purulent infection of the brain in which pus forms in the extradural, subdural, or intracerebral area of the brain most often from bacteria.
• The clinical manifestations of a brain abscess begin slowly and may include headache, fever, and neurologic deficits or nonspecific signs and symptoms.
• Computed tomography scanning determines the presence of cerebritis, hydrocephalus, or a midline shift.
• Magnetic resonance imaging detects the presence of an abscess early in the course.
• An EEG can localize the lesion in most cases, and high-voltage, slow-wave activity or electrocerebral silence may be noted in the area of the abscess.
• The mainstay of management for patients with brain abscess is systemic antibiotic therapy.
What is the first sign of ICP?
Be aware that the first sign of increased ICP is a decrease in level of consciousness.
Functions of the brainstem
The brainstem controls functions such as breathing, blood pressure, body temperature, heart rhythms, hunger and thirst, and sleep patterns. It connects the forebrain and the cerebellum with the spinal cord. All the nerve fibers leaving the brain to go to the limbs and trunk of the body pass through here.
How does the blood leave the brain if it doesn’t have a venous system ?
-Dural sinuses in the brain, blood just drains down through them into the jugular veins and into the rest of the body
Veins in the head are very thin and only can drain small amounts of blood
True or false
When people get a head injury they bleed so easliy because those venous wallls are so thin and the blood drains slower
True
What part of the brain is the primary area for blood flow?
- *Cicrle of willis is the primary area for blood flow ( i.e. like the aorta)
- Most of the aneurysm arrive in the circle of wilis
- Carotid artery disease means circle of wilis isn’t getting enough blood flow
- 750 ml per min of blood (the brain gets)
- The brain gets 750 ml which is 15-20% of the resting cardiac output
Blood brain barrier
Physiological barrier between brain and tissues
**Have tight junctures instead of pores therfore only veryyyyyy small things can get through
Specific filtering process, there has to be active transport for anything to get through
Because of that most drugs cant get through and affect the brain
Size of the particle, Lipid solubility , chemical dissociation, and protein binding are all factors
Drugs that are lipid soluble or undissociated at body pH will rapidly enter the brain and cerebrospinal fluid ( i.e. water, O2, CO2. gases, glucose, lipid soluble)
Anatomy of the meninges
Dura on outside
Arachnoid middle like spider web
Pia on the inside
What is the falx cerebra?
Falx cerebri: double fold of dura that descends into the brain, longitudinally splitting the two hemispheres
Tentorium: tent like thing, double fold of dura covers the upper part of the cerebellum, supports the occipital lobe
Glascow coma scale
KNOW the scale in book on test
Pupillary Response Respiratory Status Respiratory Patterns Blood Gas Alterations Cardiovascular Status Temperature
Opiates for neuro
Opiates for neuro problems: Diluadid, morphine, codeine
-can masks symptoms, like to get a baseline first…could diminsh RR, bradycardia, LOC, nausea
Benzos for neuro
Benzos: Propofol, lorazepam, midolzam, valium
BArbitiates for neuro
Barbiturates: Phentobarbital
Sympathothmimetic for neuro
Sympathothomimetic agents: dopamine, levothed, epinephrine, neo or phenylephrine, rocuronium
Lumbar punctures
Lumbar puncture: how do you position someone, is there ever a time when you would not go along with a lumbar puncture: yes when there is increased intracranial puncutre, why would you not…need to know on test
What is an angiography?
Angiography: need to know where the blockage or hemorrhage is, can dissolve it with clot busting drugs, within 6 hours
What is a PET scan?
Positron emission tomography ( PET scan): to see where the disease has progressed to, monitor stroke, alzehimers diseaese, seizures
MRI for neuro
Can take up to 24 hours for a bleed to show up on a ct scan
MRI can be used for : Lacunar stroke, cerebral tumor, changes in dementia, cerebral edema, dymylenating disease such as MS or ALS
What is a trancranial doppler used for?
Transcranial doppler: used to see if they are still spasming
ICP
The skull is a rigid compartment filled to capacity with essentially non-compressible contents Intracranial contents Brain matter: 80% Blood (intravascular): 10% Cerebrospinal fluid: 10%
14oo ml of brain matter
*150 of blood
*150 of CSF
Head roughly contains 1700 ml of stuff
Normal ICP range
The pressure exerted by the CSF within the ventricles.
A dynamic pressure that fluctuates in response to many factors.
Normal range is 0-15 mmHg.
Ideally the ICP is < 10 mmHg.
What is the Monro-Kellie Hypothesis?
The volume of the three components remains nearly constant.
If any one component increases in volume, another component must decrease, or the intracranial pressure (ICP) will rise.
This applies only to skulls that are fused.
IF brain matter becomes edematous then you have to decrease csf or blood volume or you will get ICP
True or false
Brain starts to atrophy over 40, therefore someone over 40 often has more room for ICP
True
Intracranial compliance
Compliance is a measure if the adaptive ability of the brain to maintain intracranial equilibrium in response to physiological and external challenges to that system
Compliance represents the ratio of change in volume to the resulting change in pressure.
