TIA

AKA

The Silent Stroke

What happens upon admission to the ED after a TIA of RIND?

Stroke is the #      most common cause of death and major disability worldwide.

TWO

Ishcemic Stroke

Caused by the occlusion of a cerebral artery by either a thrombus or an embolus.

Accounts for more than half of all strokes and are commonly associated with the development of atheroscelrosis of the blood vessel wall.

Thrombotic Stroke

Because of the gradual occlusion (blockage) of the arteries, these type of strokes tend to have a slow onset.

Thrombotic Stokes

This artery is most commonly involved in an embolic stroke.

Middle Cerebral Artery

(MCA)

Hemorrhagic Stroke

Congenital Aneurysm

A developmental defect in the media and elastica (adventitia or outer layer) of the vessel.

Secular Aneurysm

Mycotic Aneurysm

Caused by an infectious agent

Arteriovenous Malformation

(AVM)

An uncommon abnormality that occurs during embryonic development. It is a tangled mass of malformed, thin-walled, dilated vessels. Forms an abnormal communication b/w the arterial and venous systems.

Common Risk Factors for Developing a Stroke

Chart 47-2 (pg. 1033)

Arterial fibrillation or heart murmur

arteriosclerosis/atherosclerosis

Previous stroke or TIA

Heart Surgery

Valvular heart disease

Diabetes mellitus

Smoking

Substance abuse (particularly cocaine)

Obesity

Cognitive Changes:

Assess for

Denial of the illness

Spatial and proprioceptive (awareness of body position in space) dysfuntion

Impairment of memory, judgement, or problem solving and decision making abilities

Decreased ability to concentrate and attend to tasks

The Right Cerebral Hemisphere

More involved with visual and apatial awareness and proprioception. 

Changes involved with the right hemisphere

The Left Cerebral Hemisphere

The center for language, math skills, and analytic thinking.

Stroke involving the left hemisphere

Neglect Syndrome

Amaurosis Fugax

A brief episode of blindness in one eye. Results from retinal ischemia caused by ophthalmic or carotid artery insufficiency.

Hemianopsia

Blindness in half of the visual field. Results from damage to the optic tract or occipital lobe.

Homonymous Hemianopsia

Blindness in the same side of both eyes. This pt. must turn his or her head to scan the complete range of vision.

Cranial nerve responsible for the ability to chew

Five

Cranial nerve responsible for facial paralysis or paresis

Seven

Hydrocephalus

An abnormal increase in CSF volume. If left untreated it may lead to an increased ICP.

Communicating Hydrocephalus

Impaired reabsorption of CSF at the arachnoid villi (from subarachnoid hemorrhage or meningitis) 

Uncal Herniation

One of the most clinically significant and life-threatening. Caused by a shift of one or both areas of the temporal lobe, known as the uncus.

Uncal Herniation

Late findings include:

1. dilated and nonreactive pupils
2. ptosis
3. a rapidly deteriorating LOC

Central Herniation

Causes and clinical manifestations:

Caused by a downward shift of the brainstem and diencephalon from a supratentorial lesion.

Clinically manifested by Cheyne-Stokes respirations, pinpoint and nonreative pupils, and potential hemodynamic instability.

The most common causes of traumatic brain injury (TBI) in the US are:

falls and motor vehicle crashes. Alcohol and drugs are contributing factors.

Assessment and Clinical Manifestations of a Patient with a TBI

Cushing's Triad

Hypotension and tachycardia suggest:

Hypovolemic shock.

Usually due to intra-abdominal bleeding or bleeding into the soft tissue around major fractures-not to intracranial bleeding.

A decrease in arousal or increased sleepiness and coma are caused by:

pressure on the reticular activating system within the brainstem.

Pinpoint and nonresponsive pupils are indicative of:

brainstem dysfunction at the level of the pons.

Ovoid Pupil

Regarded as the midstage b/w normal and a dilated pupil.

Papilledema

aka

Choked Disc

Edema and hyperemia (increased flood flow) of

the optic disc. Always a sign of increased ICP.

Laboratory Assessment

There are no lab tests to diagnose a primary brain injury. The physician may request ABG's, a CBC, and serum glucose and electrolyte levels to monitor hemodynamic status, identify electrolyte imbalance, and detect infection.

Nonsurgical Management

Specific nursing interventions for the patient with a head injury are directed toward preventing or detecting increased ICP, promoting fluid and electrolyte balance, and monitoring the effectsof treatments and drug therapy.

Fever caused by hypothalamic damage

The patient who requires mechanical breathing assistance is ventilated to maintain a partial pressure of arterial carbon dioxide of about:

35-38 mm Hg

Criteria for brain death:

• Glasgow Coma Scale < 3
• Apnea
• No pupillary response
• No gag and cough reflexes
• No oculovestibular reflex (no eye movement after ice water is placed in ears)
• No corneal reflex
• No oculocephalic reflex ("doll's eyes")

Head positioning should be based on both:

ICP and systemic blood pressure

Mannitol (Osmitrol)

An osmotic diuretic; used to treat cerebral edema by pulling water out of the extracellular space of the edematous brain tissue. Most effective when given in boluses rather than as a continuous infusion.

Arterial oxygen levels are maintained b/w          to prevent cerebral vasodilation resulting from hypoxemia

80-100 mm Hg

Furosemide (Lasix)

A loop-diuretic; often used as adjunctive therapy to reduce the incidence of rebound from mannitol. It reduces edema and blood volume, decreases Na uptake by the brain, and decreases the production of CSF at the choroid plexus.

Neuromuscular Blocking Agents (NMBA's)

Examples include vercuronium bromide or cisatracurium (Nimbex). These agents have no analfesic and sedative effects and must never be used w/out aggresive sedation/analgesia.

Antiepileptic Drugs

Not recommended to prevent seizures that occur more than 7 days after injury. May be used to prevent seizure activity that may occur w/in 7 days after injury.

Barbiturate Coma

Complications of Barbiturate Coma

• Decreased GI motility
• Cardiac dysrhythmias from hypokalemia
• Hypotension
• Fluctuations in body temp

Why would a person with TBI be at risk for diabetes insipidus and the syndrome of inappropriate antidiuretic hormone?

Because the pituitary gland may be injured or compressed from cerebral edema.

Nutrition Management:

The pt. with a major head injury after the acute phase of management may have changes in these areas:

• Sense of smell
• Ability to taste, swallow, or feel the presence of food within the oral cavity
• Vision, pain, and temp sensation

Sensory, Cognitive, and Behavioral Management

Intraventricular Catheter (IVC)

Type of device used for monitoring ICP. A small tube that is inserted into the anterior horn of the lateral ventricle of the nondominant cerebral hemisphere.

Advantages of an IVC

CSF can be drained to decrease ICP and specimens can be obtained for laboratory analysis.

Subarachnoid Screw or Bolt

A hollow device placed into the subarachnoid space for direct pressure measurement. Less invasive, lowering the risk for infection.  Disadvantage is that CSF cannot be drained to treat increased ICP.

Epidural Catheter

A transducer that is placed b/w the skull and the dura, leaving the dura intact. Major advantage is the decreased risk for infection from an open dural space.