Stroke Flashcards
Define stroke
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
What is the aetiology of a stroke?
Hypertension, Age, Drugs/alcohol, Females have an increased risk due to Oestrogen, Inactivity, Obesity, Diabetes, High cholesterol
What are some symptoms of a stroke?
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
What are some nursing interventions for a stroke?
Maintain head of bed 30 degrees:
to facilitate jugular venous drainage and help reduce intracranial pressure
Maintain systolic blood pressure within prescribed parameters (often < 180mmHg):
to reduce the potential for further bleeding or ischaemic changes
Continuous neurological observations:
to help identify deterioration to initiate timely intervention and treatment
Ensure correct positioning of paralysed limbs:
to prevent contractures and maximise function for rehabilitation
Ensure patient is kept NBM until swallow is assessed by Speech and Language Therapist:
to prevent aspiration of oral fluid and food
Administer prescribed aspirin orally or enterally:
to impede clotting and prevent further ischaemia
Turn the patient regularly:
to maintain skin integrity and prevent pressure injury if the patient cannot move themselves
What are the two main types of stroke?
Ischaemic and Haemorrhagic
What is a cerebral embolism? (Ischaemic stroke)
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.
What is a cerebral thrombosis? (Ischaemic stroke)
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.
What is a Haemorrhagic stroke?
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
What is the patho of a Ischaemic Stroke?
Ischaemic Cascade
Disrupted blood flow
Anaerobic respiration
Lactic Acid
Insufficient ATP
Ion imbalance
Increase in intracellular calcium
Increased Glutamate
Vasoconstriction
Enlarged area of infarction into penumbra*
Cell membrane and proteins break down
Formation of free radicals
Protein production decreased
Cell injury and death
What is the patho of an Haemorrhagic stroke?
Ruptured vessel
Explosive eruption of blood from vessel into
surrounding brain tissue and structure
Haematoma develops
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
Mismatch between blood flow and metabolic
demand
Breakdown of sodium/potassium pump
maintaining cellular function
Anaerobic respiration to produce ATP
Increased production of lactic acid
Cell death
Altered pH
Cell membrane and proteins break down
Formation of free radicals
Cell injury and death
What can brainstem strokes lead to?
Coma
Breathing problems, spontaneous changes in blood pressure and heart rate
Nausea and vomiting
What can cerebellar strokes lead to?
Ataxia, dysarthria, incoordination, nystagmus
What happens in a R) sided brain injury?
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
What happens in a L) sided brain injury?
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
What is a Transient ischaemic attack (TIA)
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
