CEREBROVASCULAR DISEASE

CASE PRESENTATION

By: ICU Department

INTRODUCTION

Patient with a wide variety of medical problems are cared for in the intensive care units (ICU). In some cases, care is focused primarily on one or two target systems, and the purpose of the ICU stay is relatively straightforward. As an example, the ICU care of the patient suffering from CerebroVascular disease often follows a fairly conventional course. More often however, the critically ill patient has problems affecting multiple systems, frequently further compromised by general debilitation and decreased resistance, which presdisposes the patient to significant complications.

The patient who suffers stroke typifies this latter situation and challenges the critical care nurse to devise and execute a plan of care that addresses numerous threats to various systems. A comprehensive approach is required to relate the deficiency in one system to real or potential deficiencies in other systems.

BACKGROUND OF THE STUDY

A stroke or "brain attack" occurs when a blood clot blocks an artery (a blood vessel that carries blood from the heart to the body) or a blood vessel (a tube through which the blood moves through the body) breaks, interrupting blood flow to an area of the brain.  When either of these things happen, brain cells begin to die and brain damage occurs.

 

When brain cells die during a stroke, abilities controlled by that area of the brain are lost.  These abilities include speech, movement and memory.  How a stroke patient is affected depends on where the stroke occurs in the brain and how much the brain is damaged.

 For example, someone who has a small stroke may experience only minor problems such as weakness of an arm or leg.  People who have larger strokes may be paralyzed on one side or lose their ability to speak.  Some people recover completely from strokes, but more than 2/3 of survivors will have some type of disability.

ANATOMY AND PHYSIOLOGY (Overview)The Nervous System

The functional unit of the nervous system is the nerve cell, or neuron. The nervous system consist of the central nervous system (CNS), which includes the brain and spinal cord, and the peripheral nervous system (PNS), which includes the cranial nerves and the spinal nerves. The autonomic nerve system (ANS) is a subdivision of the PNS that automatically controls body functions such as breathing and heartbeat. It is further divided into the sympathetic and parasympathetic nervous system.

NEURONA. Primary component of the nervous system; composed of

the cell body (gray matter), axon, and dendrites.

B. Axon: Elongated process or fiber extending from the cell body; transmits impulses (messages) away from the cell body to dendrites or directly to the cell bodies of other neurons; neuron usually has only one axon.

C. Dendrites: short, branching fibers that receive impulses and conduct them toward the nerve cell body. Neurons may have many dendrites.

D. Synapse: Junction between neurons where an impulse is transmitted.

E. Neurotransmitters: Chemical agents (e.g. acetylcholine, norepinephrine) involved in the transmission of impulse across synapse.

F. Myelin sheath: a wrapping of myelin ( a whitish fatty material) that protects and insulates nerve fibers and enhances the speed of impulse conduction.

> Both axons and dendrites may or may not have a myelin sheath (myelinated/unmyelinated)

> Most axons leaving the CNS are heavily myelinated by Schwann cells.

FUNCTIONAL CLASSIFICATION

a. Afferent (sensory) neurons: transmit impulses from peripheral receptors to the CNS.

b. Efferent (motor) neurons: conduct impulses from CNS to the muscle and glands.

c. Internuncial neurons (interneurons): connecting links between afferent and efferent neurons.

Central Nervous System: Brain and Spinal Cord

BRAIN

Brain:

A. Cerebrum: outermost area (cerebral cortex) is gray matter; deeper area is composed of white matter.

1. Two hemispheres: right and left.

2. Each hemisphere divided into four lobes; many of the functional areas of the cerebrum have been located in these lobes.

The Brain Hemisphere

a. Frontal Lobe

> personality, behavior

> higher intellectual functioning

> precentral gyrus: motor function

> Broca’s area: specialized motor speech

b. Parietal Lobe

> Postcentral gyrus: register registers general sensation (e.g. touch, pressure).

> Integrates sensory information.

c. Temporal Lobe

> hearing, taste, smell

> Wernickes’s Area: sensory speech area (understanding/formulation of language)

d. Occipital lobe

> Vision

Brain Lobes

Brain Structure

3. Corpus Callosum: large fiber tract that connects the two two cerebral hemispheres.

4. Basal Ganglia: islands of gray matter within white matter of cerebrum

> regulate and integrate motor activity

> part of extrapyramidal system

B. Diencephalon: connecting part of the brain, between the cerebrum and the brain stem. Contains several small structures; the thalamus and hypothalamus are most important.

1. Thalamus

a.. Relay station for discrimination of sensory signals (e.g. pain, temperature, touch.).

b. Controls primitive emotional responses (e.g. rage, fear.)

2. Hypothalamus

a. Found immediately beneath the thalamus.

b. Plays major role in regulation of vital functions such as blood pressure, sleep, food and water intake, and body temperature.

c. Acts as control center for pituitary gland and affects both divisions of the autonomic nervous system.

C. Brainstem

1. Contains midbrain, pons, and medulla oblongata.

2. Extends from the cerebral hemispheres to the foramen magnum at the base of the skull.

3. Contains nuclei of the cranial nerves and the long ascending and descending tracts connecting the cerebrum and the spinal cord.

4. Contains vital centers of respiratory, vasomotor, and cardiac functions.

C. Cerebellum

- coordinates muscle tone and movements and maintains position in space (equilibrium)

Anatomy of the Brain

Spinal Cord

Spinal Cord:

A. Serves as a connecting link between the brain and the periphery.

B. Extends from foramen magnum to second lumbar vertebra.

C. H-shaped gray matter in the center (cell bodies) surrounded by white matter (nerve tracts and fibers).

D. Gray Matter

1. Anterior horns: contain cell bodies giving to efferent (motor) fibers.

2. Posterior horns: contain cell bodies connecting with afferent (sensory) fibers from dorsal root ganglion.

3. Lateral horns: in thoracic region, contain cells giving rise to autonomic fibers of sympathetic nervous system

E. White Matter1. Ascending tracts (sensory pathways)

a. Posterior columns: carry impulses concerned with touch, pressure, vibration, and position sense.

b. Spinocerebellar: carry impulses concerned with muscle tension and position sense to cerebellum.

c. Lateral spinothalamic: carry impulses concerned with crude touch and pressure.2. Descending tracts ( motor pathways )

a. Corticospinal (pyramidal, upper motor neuron): conduct motor impulses from motor cortex to anterior horn cells (cross in the medulla).

b. Extrpyramidal: help to maintain muscle tone and to control body movements such as walking.

F. Reflex arc1. Reflex consist of an involuntary response to a stimulus

occurring over a neural pathway called a reflex arc.2. Not relayed to and from brain; takes place at cord

levels.3. Components

a. Sensory receptor: receivesreacts to a stimulus.b. Afferent pathway: transmits impulses to spinal cord.c. Interneuron: synapses with a motor neuron (anterior horn cell).d. Efferent pathway: transmits impulses from motor neuron to effector.e. Effector: muscle or organ that responds to stimulus.

Supporting Structures

A. Skull1. Rigid; numerous bones fused together 2. Protects and supports the brain.

B. Spinal Column1. Consists of 7 cervical, 12 thoracic, and 5 lumbar vertebrae, as well as sacrum and coccyx.2. Supports the head and protects the spinal cord.

C. Meninges 1. Membranes between the skull and brain and the vertebral column and spinal cord.2. Layers

a. Dura matter: outermost layer, tough, leathery

b. Arachnoid matter: middle layer, weblike

c. Pia matter: innermost layer, delicate, clings to surface of brain.

3. Area between arachnoid and pia matter is called subarachnoid space.

D. Ventricles1. Four fluid-filled cavities connecting with one another and the spinal canal.2. Produce and circulate cerebrospinal fluid.

Cerebro Spinal Fluid (CSF)E. Cerebrospinal Fluid

1. Surrounds brain and spinal cord2. Offers protection by functioning as a shock absorber.3. Allows fluid shifts from the cranial cavity to the spinal cavity.4. Carries nutrients to and waste products away from the nerve cell.

F. Vascular Supply1. Two internal carotid arteries – anterior.2. Two vertebral arteries leading to basilar artery – posterior.3. These arteries communicate at the base of the brain through the Circle of Willis.4. Anterior, middle, and posterior cerebral arteries are the main arteries for distributing blood to each hemisphere of the brain.5. Brainstem and cerebellum are supplied by branches of the vertebral and basilar arteries.6. Venous blood drains into dural sinuses and then into internal jugular veins.

G. Blood brain barrier: protective barrier preventing harmful agents from entering the capillaries of the CNS; protects brain and spinal cord.

Vascular Supply

Circle of Willis

The Circle of Willis is the joining area of several arteries at the bottom (inferior) side of the brain. At the Circle of Willis, the internal carotid arteries branch into smaller arteries that supply oxygenated blood to over 80% of the cerebrum.

Peripheral Nervous SystemSpinal NervesA. 31 pairs: carry impulses to and from spinal cord.B. Each segment of the spinal cord contains a pair of spinal

nerves (one for each side of the body).C. Each nerve is attached to the spinal cord by two roots.

1. Dorsal (posterior) root: contain afferent(sensory) nerve whose cell body is in the dorsal root ganglion.2. Ventral (anterior) root: contains efferent (motor) nerve whose nerve fibers originate in the anterior horn cell of the spinal cord (lower motor neuron).

Cranial NervesA. 12 pairs: carry impulses to and from brainB. May have sensory, motor, or mixed functions.

Cranial Nerve

Name Function

I Olfactory Sensory: carries impulses for sense of smell

II Optic Sensory: carries impulses for vison

III Oculomotor Motor: muscles for pupillary constriction, elecvation of upper eyelid; 4 out of 6 extraocular movements

IV Trochlear Motor: muscles for downward, inward movement of the eye

V Trigeminal Mixed: Impulses form face, surface of eyes (corneal reflex); muscles controlling mastication

Cranial Nerves

Cranial Nerve

Name Function

VI Abducens Motor: muscles for lateral deviation of the eye

VII Facial Mixed: impulses for taste from anterior tongue; muscles for facial movement

VIII Acoustic Sensory: impulses for hearing (cochlear division) and balance (vestibular division)

IX Glossopharyngeal

Mixed: impulses for sensation to posterior tongue and pharynx; muscles for movement of pharynx (elevation) and swallowing

Cranial Nerve

Name Function

X Vagus Mixed: impulses for sensation to lower pharynx and larynx; muscles for movement of soft palate, pharynx, and larynx

XI SpinalAccessory

Motor: movement of sternomastoid muscles and upper part of trapezius muscle

XII Hypoglossal Motor: movement of the tongue

Autonomic Nervous SystemA. Part of the peripheral nervous systemB. Includes those peripheral nerves (both cranial and

spinal) that regulate functions occurring automatically in the body, ANS regulates smooth muscle, cardiac muscle and glands.

C. Components1. Sympathetic nervous system: generally accelerates some body functions in response to stress.2. Parasympathetic nervous system: controls normal body functioning.

EFFECTS OF AUTONOMIC NERVOUS SYSTEM ACTIVITY

Effector Sympathetic(Adrenergic)

Effects

Parasympathetic (Cholinergic) Effects

Eye Dilates pupil (mydriasis)

Constricts pupil (miosis)

Glands of headLacrimalSalivary

No effectScantly thick, viscous secretions; dry mouth

Stimulates secretionCopious thin, watery secretions

Heart Increase rate and force of contraction

Decreases rate

Effector Sympathetic(Adrenergic)

Effects

Parasympathetic (Cholinergic) Effects

Blood Vessels Constricts smooth muscles of skin, abdominal blood vessels, and cutaneous blood vesselsDilates smooth muscle of bronchioles, blood vessels of heart, and skeletal muscle of heart.

No effect

Lungs Bronchodilation Bronchoconstriction

Effector Sympathetic(Adrenergic)

Effects

Parasympathetic (Cholinergic) Effects

GI Tract Decreases motilityConstricts sphinctersPossibly inhibits secretionsInhibits activity of gallbladder and ductsInhibits glycogenolysis in liver

Increases motilityRelaxes sphinctersStimulates secretionStimulates activity of gallbladder and ducts

Effector Sympathetic(Adrenergic)

Effects

Parasympathetic (Cholinergic) Effects

Adrenal Gland Stimulates secretion ofEpinephrine and norepinephrine

No effects

Urinary Tract Relaxes detrusor muscleContracts trigone sphincter (prevents voiding)

Contracts detrusor muscleRelaxes trigone sphincter (allows voiding)

What is CVD (Stroke)? Stroke is the No. 1 cause of adult

disability. 80% of strokes are preventable;

you can prevent a stroke!

Ischemic Stroke In everyday life, blood

clotting is beneficial. When you are bleeding from a wound, blood clots work to slow and eventually stop the bleeding. In the case of stroke, however, blood clots are dangerous because they can block arteries and cut off blood flow, a process called ischemia.

An ischemic stroke can occur in two ways: embolic and thrombotic strokes

Embolic Stroke In an embolic stroke, a

blood clot forms somewhere in the body (usually the heart) and travels through the bloodstream to your brain. Once in your brain, the clot eventually travels to a blood vessel small enough to block its passage. The clot lodges there, blocking the blood vessel and causing a stroke. The medical word for this type of blood clot is embolus.

 

Thrombotic Stroke In the second type of

blood-clot stroke, blood flow is impaired because of a blockage to one or more of the arteries supplying blood to the brain. The process leading to this blockage is known as thrombosis. Strokes caused in this way are called thrombotic strokes. That's because the medical word for a clot that forms on a blood-vessel deposit is thrombus.

Blood-clot strokes can also happen as the result of unhealthy blood vessels clogged with a buildup of fatty deposits and cholesterol. Your body regards these buildups as multiple, tiny and repeated injuries to the blood vessel wall. So your body reacts to these injuries just as it would if you were bleeding from a wound;it responds by forming clots. Two types of thrombosis can cause stroke: large vessel thrombosis and small vessel disease (or lacunar infarction.)

Large Vessel ThrombosisThrombotic stroke occurs most often in the large arteries, so large vessel thrombosis is the most common and best understood type of thrombotic stroke. Most large vessel thrombosis is caused by a combination of long-term atherosclerosis followed by rapid blood clot formation. Thrombotic stroke patients are also likely to have coronary artery disease, and heart attack is a frequent cause of death in patients who have suffered this type of brain attack.

Small Vessel Disease/Lacunar InfarctionSmall vessel disease, or lacunar infarction, occurs when blood flow is blocked to a very small arterial vessel. The term's origin is from the Latin word lacuna which means hole, and describes the small cavity remaining after the products of deep infarct have been removed by other cells in the body. Little is known about the causes of small vessel disease, but it is closely linked to hypertension (high blood pressure).

Hemorrhagic Stroke

Strokes caused by the breakage or "blowout" of a blood vessel in the brain are called hemorrhagic strokes. The medical word for this type of breakage is hemorrhage. Hemorrhages can be caused by a number of disorders which affect the blood vessels, including long-standing high blood pressure and cerebral aneurysms. There are two types of hemorrhagic stroke subarachnoid and intracerebral.

 

There are two types of hemorrhagic stroke subarachnoid and intracerebral.

 

An aneurysm is a weak or thin spot on a blood vessel wall. These weak spots are usually present at birth. Aneurysms develop over a number of years and usually don't cause detectable problems until they break.

 

In an intracerbral hemorrhage, bleeding occurs from vessels within the brain itself. Hypertension (high blood pressure) is the primary cause of this type of hemorrhage.

Intracerebral Hemorrhage

. In a subarachnoid hemmorrhage(SAH), an aneurysm bursts in a large artery on or near the thin, delicate membrane surrounding the brain. Blood spills into the area around the brain which is filled with a protective fluid,causing the brain to be surrounded by blood-contaminated fluid

Stroke SymptomsStroke Symptoms include:   Sudden numbness or weakness of face, arm or

leg - especially on one side of the body. Sudden confusion, trouble speaking or

understanding. Sudden trouble seeing in one or both eyes. Sudden trouble walking, dizziness, loss of

balance or coordination. Sudden severe headache with no known

cause.

Strokes may cause temporary or permanent loses of motor function, thought processes, memory, speech, or sensory function. Difficulty with swallowing and speaking, hemiplegia, and visual field defects are also related complications of this disease.

Treatment is aimed at supporting vital functions, ensuring adequate cerebral perfusion, and prevention of major complications or permanent disability

RISK FACTORS IN STROKE

Advance Age High Cholesterol Obesity Transient Ischemic Attacks (TIA). Diabetes Mellitus Oral contaceptives (especially with co-

existing hypertension, smoking, and high estrogen levels.)

Smoking Elevated Blood Lipids

PATHOPHYSIOLOGYCVA

(stroke)Cerebral Hemorrhage

Occlusion of Major vessel by

embolism

Other causes of Ischemia

Cerebral Infarction

Decreased Blood Flow to the Brain

Hypoxia

Ischemia

Inadequate adenosine triphosphate (ATP)

Neurotransmitter depletion

Cerebral Edema

Vascular congestion

Compression of tissue

Impaired function

Posterior Cerebral Artery

Middle Cerebral Artery

Anterior Cerebral Artery

Hemiparesis

Ataxia

Visual problems

Dysphasia

Arm paralysis

Hemianopia

Aphasia

Agnosia

Perception deficits

Confusion

Impaired thought

Contralateral paralysis

Urinary Incontinence

Sensory deficits

Further compression of tissues

Decreases edema

Function improved

Continued inadequate blood flow

Return of normal perfusion

CEREBRAL DEATH

Good Prognosis

Poor Prognosis

MEDICAL MANAGEMENT

> For an ischemic stroke, treatment focuses on restoring blood flow to the brain. If less than 3 hours have passed since your symptoms began, doctors may use a medicine that dissolves blood clots. Research shows that this medicine can improve recovery from a stroke, especially if given within 90 minutes of the first symptoms. Other medicines may be given to prevent blood clots and control symptoms.

MEDICAL MANAGEMENT A hemorrhagic stroke can be hard to treat. Doctors may

do surgery or other treatments to stop bleeding or reduce pressure on the brain. Medicines may be used to control blood pressure, brain swelling, and other problems.

After your condition is stable, treatment shifts to preventing other problems and future strokes. You may need to take a number of medicines to control conditions that put you at risk for stroke, such as high blood pressure, high cholesterol, and diabetes. Some people need to have a surgery to remove plaque build up from the blood vessels that supply the brain (carotid arteries).

PLAN / IMPLEMENTATION Immediate Care

a. Maintain patent airwayb. Minimize activityc. Keep head bed elevated 15-30 angled. Maintain proper body alignmente. Keep side rails in upright position

PLAN / IMPLEMENTATION Intermediate care and Rehabilatative needs

a. position for good body alignmentb. Institute measures that facilitates swallowing

1. Allow patient to sit in upright position2. Instruct client to use tongue actively3. Administer liquids slowly, avoid milk

based products.4. Place food on unaffected side of mouth5. Provide semisolid foods. (easiest to

swallow)6. Instruct to swallow while eating; maintain

upright position for 30 – 45 minutes after eating.

PLAN / IMPLEMENTATION c. Monitor elimination patterns d. Provide skin care e. Perform passive and active ROM

exercises f. Orient to person, time and place. g. Move affected extremities slowly and

gently. h. Teach use of supportive devices (e.g.

commode, trapeze and cane.)

PLAN / IMPLEMENTATION i. Address communication needs –

face patient and speak clearly and slowly; give the patient time to respond; use verbal and non verbal communication?

j. Do not approach from visually impaired side.

DISCHARGE PLAN Lifestyle changes that can reduce the risk of

stroke and improve overall health. Don't smoke. Smoking can more than double

the risk of stroke. Avoid secondhand smoke too.

DISCHARGE PLAN Eat a heart-healthy diet that includes plenty of

fish, fruits, vegetables, beans, high-fiber grains and breads, and olive oil. Eat less salt too.

DISCHARGE PLAN Get exercise on most, preferably all, days of

the week. Your doctor can suggest a safe level of exercise for you.

Stay at a healthy weight.

Control your cholesterol and blood pressure.

If you have diabetes, keep your blood sugar as close to normal as possible.

DISCHARGE PLAN

Limit alcohol. Having more than 2 drinks a day increases the risk of stroke.

Take a daily aspirin or other medicines if your doctor advises it.

DISCHARGE PLAN

THANK YOU !