Perfusion Part 5 - Brain Injuries

Question 1

Injury in the brain results in: (3)

Answer 1

1. Bleeding.
2. Ischemia.
3. Inflammation.

Question 2

Why is injury in the brain particularly dangerous? (What does it lack? What does that mean it can or cannot do?)

Answer 2

Neurons lack centrioles, meaning CNS cells do not regenerate and necrosis will result in permanently decreased function.

Question 3

What are 2 clinical manifestations of brain injury?

Answer 3

1. NVS (VS + PERRLA): can use GCS

2. Neurological deficits related to affected areas

Question 4

What is Cushing’s Triad?

Answer 4

Low HR
Low RR
Widened pulse pressure (difference between systolic & diastolic)

Question 5

What is Cushing’s Triad an indicator of?

Answer 5

Increased intracranial pressure.

Question 6

What is ischemia?

Answer 6

Decreased delivery of O2.

Question 6

What is hypoxia?

Answer 6

Decreased O2 levels in tissues.

Question 7

What is hypoxemia?

Answer 7

Low levels of O2 in the blood.

Question 8

What are the 3 types of cerebral edema?

Answer 8

1. Vasogenic.
2. Cytotoxic.
3. Combination.

Question 9

Vasogenic cerebral edema is a result of:

Answer 9

The BBB being compromised.

Question 10

What are 3 possible causes for a compromised BBB?

Answer 10

1. Head injury.
2. Hematoma.
3. Hemorrhage.

Question 11

What are the 4 steps leading up to vasogenic cerebral edema?

Answer 11

1. BBB compromise.
2. CNS infection.
3. Inflammation.
4. Increased permeability.

Question 12

Why does hematoma compromise BBB integrity?

Answer 12

The blood causes an increase in pressure against the BBB.

Question 13

Cytotoxic cerebral edema is caused by:

Answer 13

Increased intracellular fluid shift.

Question 14

Which type of cerebral edema would we see sudden onset of Cushing’s Triad in?

Answer 14

Cytotoxic.

Question 15

What are the 2 types of CVA?

Answer 15

1. Ischemic.

2. Hemorrhagic.

Question 15

What are the 2 types of CVA?

Answer 15

1. Ischemic.

2. Hemorrhagic.

Question 16

How do we tell the difference between the 2 types of CVA?

Answer 16

CT scan.

Question 17

What causes an ischemic stroke?

Answer 17

A thrombus/embolus.

Question 18

Which is the more common type of CVA?

Answer 18

Ischemic.

Question 19

List some risk factors for ischemic stroke.

Answer 19

HTN
Atherosclerosis
Smoking
Dyslipidemia
Stenosis (narrowing of blood vessels)
Diabetes
A fib (embolus caused by blood stasis)
Meds (ex: estrogen)
Age

Question 20

What are transient ischemic attacks (TIAs)?

Answer 20

“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.

Question 21

What are the signs of a TIA?

Answer 21

Acronym: FAST
Face (drooping, asymmetry)
Arms (can they raise both - motor symmetry)
Speech (slurred/jumbled)
Time (call 911 ASAP)

Question 22

What is the best immediate treatment for ischemic CVAs? When must be administer it by?

Answer 22

Thrombolytics: must be used WITHIN 3 HOURS of onset of signs and symptoms.

Question 23

Besides thrombolytics, what else can we do to treat ischemic CVA? (2)

Answer 23

``` Carotid endartectomy (scraping plaque from vessel). Cerebral angioplasty ```

Question 24

List some risk factors for hemorrhagic CVAs.

Answer 24

``` HTN Meds (antiplatelets or coagulants) Age Arterial deficits (ex: atriovenous malformation (AVM), aneurysm) Bleeding disorders (ex: haemophilia) ```

Question 25

What is the first and most characteristic symptom of a hemorrhagic CVA?

Answer 25

Headache ("worst headache I've ever had")

Question 26

Signs & symptoms of a hemorrhagic stroke will take on a ______ onset.

Answer 26

Sudden.

Question 27

What are sequelae associated with hemorrhagic CVAs?

Answer 27

``` Hemorrhage Ischemia ICP Edema Necrosis Death ```

Question 28

List some ways we can stabilize a patient with a hemorrhagic CVA in an emergency situation.

Answer 28

Intubation Sedation Anything that will optimize perfusion by minimizing effort & avoiding vasoconstriction Reverse anticoagulation

Question 29

Emergency treatment of hemorrhagic CVA can include use of [drug] and [fluid] because:

Answer 29

``` 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. ```

Question 30

What is AVM (ateriovenous malformation)?

Answer 30

Congenital defect where a bundle of arteries & veins lack a capillary network (and therefore normal wall structure).

Question 31

Why is AVM problematic?

Answer 31

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).

Question 32

What are 3 signs & symptoms of AVM?

Answer 32

1. Slow onset of neuro deficits 2. Headaches. 3. Seizures.

Question 33

What are 3 treatments for AVM? Which of these is most ideal and common?

Answer 33

1. Gamma knife radiation therapy: most common & least invasive, so most ideal. 2. Surgical removal. 3. Embolization: glue off the affected area & force body to work around it.

Question 34

Where do brain aneurysms most commonly occur?

Answer 34

In the subarachnoid space, >80% in the Circle of Willis.

Question 35

List some risk factors for aneurysms.

Answer 35

``` Family history. Diet. Atherosclerosis. HTN. Malformed vessels (thin). Age: decreased collagen & elastin. ```

Question 36

What procedure do we treat cerebral aneurysms with?

Answer 36

Coiling/flow diversion: blood does not flow through bulge/weakened area, reducing risk of rupture.

Question 37

What are some causes of a cardiac tamponade? (5)

Answer 37

1. Aortic aneurysm. 2. Cardiac rupture (ex: MI). 3. Cardiac intervention (PTCA). 4. Cardiac surgery. 5. Trauma.

Question 38

How does a cardiac tamponade ultimately result in heart failure? (3 steps)

Answer 38

1. Blood in pericardial space places pressure on myocardium. 2. Pressure decreases CO. 3. Compensatory SNS stimulation (makes it worse). 4. Heart failure.

Question 39

Describe the primary sign/symptom of a cardiac tamponade.

Answer 39

Pulsus paradoxus: systolic BP decreases with inspiration due to increased thoracic pressure.

Question 40

What are 4 causes of intracerebral hematomas?

Answer 40

1. Ruptured cerebral aneurysm. 2. Ruptured AVM. 3. Hemorrhagic stroke. 4. Associated with head injury.

Question 41

What is a common cause of epidural hematoma?

Answer 41

Skull fracture injury.

Question 42

What is the most common cause of subdural hematomas?

Answer 42

Acceleration/deceleration injuries (results in venous tearing due to shearing force).