Perfusion Part 5 - Brain Injuries Flashcards
Injury in the brain results in: (3)
- Bleeding.
- Ischemia.
- Inflammation.
Why is injury in the brain particularly dangerous? (What does it lack? What does that mean it can or cannot do?)
Neurons lack centrioles, meaning CNS cells do not regenerate and necrosis will result in permanently decreased function.
What are 2 clinical manifestations of brain injury?
- NVS (VS + PERRLA): can use GCS
2. Neurological deficits related to affected areas
What is Cushing’s Triad?
Low HR
Low RR
Widened pulse pressure (difference between systolic & diastolic)
What is Cushing’s Triad an indicator of?
Increased intracranial pressure.
What is ischemia?
Decreased delivery of O2.
What is hypoxia?
Decreased O2 levels in tissues.
What is hypoxemia?
Low levels of O2 in the blood.
What are the 3 types of cerebral edema?
- Vasogenic.
- Cytotoxic.
- Combination.
Vasogenic cerebral edema is a result of:
The BBB being compromised.
What are 3 possible causes for a compromised BBB?
- Head injury.
- Hematoma.
- Hemorrhage.
What are the 4 steps leading up to vasogenic cerebral edema?
- BBB compromise.
- CNS infection.
- Inflammation.
- Increased permeability.
Why does hematoma compromise BBB integrity?
The blood causes an increase in pressure against the BBB.
Cytotoxic cerebral edema is caused by:
Increased intracellular fluid shift.
Which type of cerebral edema would we see sudden onset of Cushing’s Triad in?
Cytotoxic.
What are the 2 types of CVA?
- Ischemic.
2. Hemorrhagic.
What are the 2 types of CVA?
- Ischemic.
2. Hemorrhagic.
How do we tell the difference between the 2 types of CVA?
CT scan.
What causes an ischemic stroke?
A thrombus/embolus.
Which is the more common type of CVA?
Ischemic.
List some risk factors for ischemic stroke.
HTN Atherosclerosis Smoking Dyslipidemia Stenosis (narrowing of blood vessels) Diabetes A fib (embolus caused by blood stasis) Meds (ex: estrogen) Age
What are transient ischemic attacks (TIAs)?
“Angina of the brain”: transient (temporary) warning signs of CVA risk, but may not always appear.
Cerebral artery is temporarily blocked, decreasing blood flow to the brain.
What are the signs of a TIA?
Acronym: FAST Face (drooping, asymmetry) Arms (can they raise both - motor symmetry) Speech (slurred/jumbled) Time (call 911 ASAP)
What is the best immediate treatment for ischemic CVAs? When must be administer it by?
Thrombolytics: must be used WITHIN 3 HOURS of onset of signs and symptoms.
Besides thrombolytics, what else can we do to treat ischemic CVA? (2)
Carotid endartectomy (scraping plaque from vessel). Cerebral angioplasty
List some risk factors for hemorrhagic CVAs.
HTN Meds (antiplatelets or coagulants) Age Arterial deficits (ex: atriovenous malformation (AVM), aneurysm) Bleeding disorders (ex: haemophilia)
What is the first and most characteristic symptom of a hemorrhagic CVA?
Headache (“worst headache I’ve ever had”)
Signs & symptoms of a hemorrhagic stroke will take on a ______ onset.
Sudden.
What are sequelae associated with hemorrhagic CVAs?
Hemorrhage Ischemia ICP Edema Necrosis Death
List some ways we can stabilize a patient with a hemorrhagic CVA in an emergency situation.
Intubation
Sedation
Anything that will optimize perfusion by minimizing effort & avoiding vasoconstriction
Reverse anticoagulation
Emergency treatment of hemorrhagic CVA can include use of [drug] and [fluid] because:
Osmotic diuretics (ex: Mannitol); hypertonic NS (ex: 3% NaCl IV solution) These will draw water into the circulation and out of the cells, decreasing cerebral edema.
What is AVM (ateriovenous malformation)?
Congenital defect where a bundle of arteries & veins lack a capillary network (and therefore normal wall structure).
Why is AVM problematic?
Capillary network is supposed to provide a gradual pressure transition, but without it, the high pressure blood from arteries enters veins rapidly. The venous system is designed to handle low pressure so its walls are thin and may rupture (hemorrhage).
What are 3 signs & symptoms of AVM?
- Slow onset of neuro deficits
- Headaches.
- Seizures.
What are 3 treatments for AVM? Which of these is most ideal and common?
- Gamma knife radiation therapy: most common & least invasive, so most ideal.
- Surgical removal.
- Embolization: glue off the affected area & force body to work around it.
Where do brain aneurysms most commonly occur?
In the subarachnoid space, >80% in the Circle of Willis.
List some risk factors for aneurysms.
Family history. Diet. Atherosclerosis. HTN. Malformed vessels (thin). Age: decreased collagen & elastin.
What procedure do we treat cerebral aneurysms with?
Coiling/flow diversion: blood does not flow through bulge/weakened area, reducing risk of rupture.
What are some causes of a cardiac tamponade? (5)
- Aortic aneurysm.
- Cardiac rupture (ex: MI).
- Cardiac intervention (PTCA).
- Cardiac surgery.
- Trauma.
How does a cardiac tamponade ultimately result in heart failure? (3 steps)
- Blood in pericardial space places pressure on myocardium.
- Pressure decreases CO.
- Compensatory SNS stimulation (makes it worse).
- Heart failure.
Describe the primary sign/symptom of a cardiac tamponade.
Pulsus paradoxus: systolic BP decreases with inspiration due to increased thoracic pressure.
What are 4 causes of intracerebral hematomas?
- Ruptured cerebral aneurysm.
- Ruptured AVM.
- Hemorrhagic stroke.
- Associated with head injury.
What is a common cause of epidural hematoma?
Skull fracture injury.
What is the most common cause of subdural hematomas?
Acceleration/deceleration injuries (results in venous tearing due to shearing force).
