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.
Primary component of the nervous system; composed of the cell body (gray matter), axon, and dendrites.
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.
Dendrites: short, branching fibers that receive impulses and conduct them toward the nerve cell body. Neurons may have many dendrites.
Synapse: Junction between neurons where an impulse is transmitted.
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.
Afferent (sensory) neurons: transmit impulses from peripheral receptors to the CNS.
Efferent (motor) neurons: conduct impulses from CNS to the muscle and glands.
Internuncial neurons (interneurons): connecting links between afferent and efferent neurons.
Central Nervous System: Brain and Spinal Cord
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
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.
a.. Relay station for discrimination of sensory signals (e.g. pain, temperature, touch.).
b. Controls primitive emotional responses (e.g. rage, fear.)
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.
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.
- coordinates muscle tone and movements and maintains position in space (equilibrium)
Anatomy of the Brain
Serves as a connecting link between the brain and the periphery.
Extends from foramen magnum to second lumbar vertebra.
H-shaped gray matter in the center (cell bodies) surrounded by white matter (nerve tracts and 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 Matter
1. 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 arc
1. 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.
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.
1. Rigid; numerous bones fused together
2. Protects and supports the brain.
B. Spinal Column
1. 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.
1. Membranes between the skull and brain and the vertebral column and spinal cord.
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.
1. 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 cord
2. 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 Supply
1. 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.
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 System
A. 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).
A. 12 pairs: carry impulses to and from brain
B. May have sensory, motor, or mixed functions.
Cranial Nerves Function Name Cranial Nerve Mixed: Impulses form face, surface of eyes (corneal reflex); muscles controlling mastication Trigeminal V Motor : muscles for downward, inward movement of the eye Trochlear IV Motor: muscles for pupillary constriction, elecvation of upper eyelid; 4 out of 6 extraocular movements Oculomotor III Sensory: carries impulses for vison Optic II Sensory: carries impulses for sense of smell Olfactory I
Function Name Cranial Nerve Mixed : impulses for sensation to posterior tongue and pharynx; muscles for movement of pharynx (elevation) and swallowing Glossopharyngeal IX Sensory: impulses for hearing (cochlear division) and balance (vestibular division) Acoustic VIII Mixed: impulses for taste from anterior tongue; muscles for facial movement Facial VII Motor: muscles for lateral deviation of the eye Abducens VI
Function Name Cranial Nerve Motor: movement of the tongue Hypoglossal XII Motor: movement of sternomastoid muscles and upper part of trapezius muscle Spinal Accessory XI Mixed: impulses for sensation to lower pharynx and larynx; muscles for movement of soft palate, pharynx, and larynx Vagus X
Autonomic Nervous System
A. Part of the peripheral nervous system
B. Includes those peripheral nerves (both cranial and spinal) that regulate functions occurring automatically in the body, ANS regulates smooth muscle, cardiac muscle and glands.
1. 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 Parasympathetic (Cholinergic) Effects Sympathetic (Adrenergic) Effects Effector Decreases rate Increase rate and force of contraction Heart Stimulates secretion Copious thin, watery secretions No effect Scantly thick, viscous secretions; dry mouth Glands of head Lacrimal Salivary Constricts pupil (miosis) Dilates pupil (mydriasis) Eye
Parasympathetic (Cholinergic) Effects Sympathetic (Adrenergic) Effects Effector Bronchoconstriction Bronchodilation Lungs No effect Constricts smooth muscles of skin, abdominal blood vessels, and cutaneous blood vessels Dilates smooth muscle of bronchioles, blood vessels of heart, and skeletal muscle of heart. Blood Vessels
Parasympathetic (Cholinergic) Effects Sympathetic (Adrenergic) Effects Effector Increases motility Relaxes sphincters Stimulates secretion Stimulates activity of gallbladder and ducts Decreases motility Constricts sphincters Possibly inhibits secretions Inhibits activity of gallbladder and ducts Inhibits glycogenolysis in liver GI Tract
80% of strokes are preventable; you can prevent a 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
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.
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 Thrombosis Thrombotic 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 Infarction Small 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).
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.
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 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
Transient Ischemic Attacks (TIA).
Oral contaceptives (especially with co-existing hypertension, smoking, and high estrogen levels.)
Elevated Blood Lipids
PATHOPHYSIOLOGY CVA (stroke) Cerebral Hemorrhage Occlusion of Major vessel by embolism Other causes of Ischemia Cerebral Infarction Decreased Blood Flow to the Brain Hypoxia
Further compression of tissues Decreases edema Function improved Continued inadequate blood flow Return of normal perfusion CEREBRAL DEATH Good Prognosis Poor Prognosis
> 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.
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
a. Maintain patent airway
b. Minimize activity
c. Keep head bed elevated 15-30 angle
d. Maintain proper body alignment
e. Keep side rails in upright position
PLAN / IMPLEMENTATION
Intermediate care and Rehabilatative needs
a. position for good body alignment
b. Institute measures that facilitates swallowing
1. Allow patient to sit in upright position
2. Instruct client to use tongue actively
3. Administer liquids slowly, avoid milk based products.
4. Place food on unaffected side of mouth
5. 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.
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.
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.
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.
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.