Weel 4 - Stroke

Question 1

Define stroke

Answer 1

Rapidly developing clinical signs of focal (or global in case of coma) disturbance of cerebral function

Lasting more than 24 hours or leading to death

Question 2

What is the aetiology of a stroke?

Answer 2

Hypertension, Age, Drugs/alcohol, Females have an increased risk due to Oestrogen, Inactivity, Obesity, Diabetes, High cholesterol

Question 3

What are some symptoms of a stroke?

Answer 3

Trouble walking, trouble speaking and/or understanding, one-sided weakness or paralysis

Motor deficits (mobility, swallowing, gag reflex, respiratory)
Communication (speaking, aphasia)
Intellectual function (memory, judgement)
Affect (trouble controlling emotions

Question 4

What are some nursing interventions for a stroke?

Answer 4

1. Maintain head of bed 30 degrees:
   to facilitate jugular venous drainage and help reduce intracranial pressure
2. Maintain systolic blood pressure within prescribed parameters (often < 180mmHg):
   to reduce the potential for further bleeding or ischaemic changes
3. Continuous neurological observations:
   to help identify deterioration to initiate timely intervention and treatment
4. Ensure correct positioning of paralysed limbs:
   to prevent contractures and maximise function for rehabilitation
5. Ensure patient is kept NBM until swallow is assessed by Speech and Language Therapist:
   to prevent aspiration of oral fluid and food
6. Administer prescribed aspirin orally or enterally:
   to impede clotting and prevent further ischaemia
7. Turn the patient regularly:
   to maintain skin integrity and prevent pressure injury if the patient cannot move themselves

Question 5

What are the two main types of stroke?

Answer 5

Ischaemic and Haemorrhagic

Question 6

What is a cerebral embolism? (Ischaemic stroke)

Answer 6

Cerebral embolism is a blood clot or debris formed elsewhere in the body which travels to the brain. If it cannot pass through the lumen it will occlude the vessel, interrupting blood flow causing tissue ischaemia.

Question 7

What is a cerebral thrombosis? (Ischaemic stroke)

Answer 7

Cerebral thrombosis is a narrowing of the cerebral arteries caused by plaque build-up. A clot then forms on the plaque, occluding the vessel lumen and restricting blood flow to an area of the brain. Tissue ischaemia results if not thrombolysed.

Question 8

What is a Haemorrhagic stroke?

Answer 8

A burst blood vessel will cause blood to leak into brain tissue and surrounding structures, causing a rise in intracranial pressure and damage to brain tissue

Question 9

What is the patho of a Ischaemic Stroke?

Answer 9

• Ischaemic Cascade
  
  1. Disrupted blood flow
  2. Anaerobic respiration
  3. Lactic Acid
  4. Insufficient ATP
• Ion imbalance
  
  1. Increase in intracellular calcium
  2. Increased Glutamate
  3. Vasoconstriction
• Enlarged area of infarction into penumbra*
  
  1. Cell membrane and proteins break down
  2. Formation of free radicals
  3. Protein production decreased
  4. Cell injury and death

Question 10

What is the patho of an Haemorrhagic stroke?

Answer 10

• Ruptured vessel
  
  1. Explosive eruption of blood from vessel into
     surrounding brain tissue and structure
  2. Haematoma develops
  3. Exposure of brain to blood, an increase in
     intracranial pressure caused by sudden entry of
     blood into the tissue, and secondary ischaemia result
     from reduced blood flow/perfusion
• Ion imbalance
  
  1. Mismatch between blood flow and metabolic
     demand
  2. Breakdown of sodium/potassium pump
     maintaining cellular function
  3. Anaerobic respiration to produce ATP
  4. Increased production of lactic acid
• Cell death
  
  1. Altered pH
  2. Cell membrane and proteins break down
  3. Formation of free radicals
  4. Cell injury and death

Question 11

What can brainstem strokes lead to?

Answer 11

• Coma
• Breathing problems, spontaneous changes in blood pressure and heart rate
• Nausea and vomiting

Question 12

What can cerebellar strokes lead to?

Answer 12

Ataxia, dysarthria, incoordination, nystagmus

Question 13

What happens in a R) sided brain injury?

Answer 13

Paralysed left side

Special perceptual deficits

Quick, impulsive behavioural style

Memory deficits
Short attention span, impulsive (safety concerns), impaired judgement (tends to minimise problems), impaired time concepts

Question 14

What happens in a L) sided brain injury?

Answer 14

Paralysed right side

Speech and language deficits

Slow, cautious behavioural style

Memory deficits

Aware of deficits (more prone to anxiety, depression), impaired comprehension r/t language/mathematics

Question 15

What is a Transient ischaemic attack (TIA)

Answer 15

A temporary focal loss of neurological function caused by ischaemia (less than 24hrs)

Most resolve within 1-2 hours

Result from inadequate blood flow to brain from partial or complete occlusion of an artery