unconcious and coma cnh. objectives describe the patophysiology of altered loc describe the...
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Objectives
Describe the patophysiology of altered LOC
Describe the clinical manifestation of altered LOC
Identify assessment & diagnostic finding
Identify complications of altered LOC
Identify medical management for client with altered LOC
Identify nursing interventions for client with altered LOC
Altered Cerebral Function
Altered Cerebral Function occurs with illness and injury
Brain Function Deterioration
Altered Level of Consciousness (LOC)
Consciousness
Condition in which person is aware of self and environment and able to respond to stimuli appropriately
Requires Arousal: alertness; dependent upon reticular activating system
(RAS); system of neurons in thalamus and upper brain stem Cognition: complex process involving all mental activities;
controlled by cerebral hemispheres
Terms used to describe LOCTerm Characteristics of client
Full consciousness AlertOrientated to person, place, timeComprehends spoken and written words
Confusion Unable to think rapidly and clearlyEasily bewildered with poor memory, short attention spanJudgment impaired
Disorientation Not aware or orientated to people, place and time
Obtundation LethargicResponsive to verbal stimuli or tactile but quickly draft back to sleep
Stupor Generally unresponsiveMay be briefly aroused by vigorous, repeated or painful stimuliMay shrink away from or grab at the source of stimuli
Semicomatose Does not move spontaneouslyUnresponsive to stimuli although by vigorous or painful stimuliMay result in stirring, moaning or withdrawal from the stimuli, without actual arousal
Coma Unarousable, will not stir or moan in response to any stimulusMay exhibit nonpurposeful response (slight movement) of area stimulated but makes no attempt to withdraw
Deep coma Completely unarousable and unresponsive to any kind of stimulus including painAbsense of corneal, pupillary, pharyngeal, tendon and plantal reflexes
Pathophysiology
Lesions or injuries affecting cerebral hemisphere directly or that compress or destroy neurons in RAS
Metabolic disorders
Arousal affected by:Destruction of RAS:
stroke, demyelinating diseases
Compression of brain stem producing edema and ischemia: tumors, increased intracranial pressure,
hematomas or hemorrhage, aneurysm
Cerebral hemisphere function depends on continuous supply or oxygen and glucoseMost common impairment caused by global
ischemia, hypoglycemia
Processes within brain that destroy or compress structures affect LOC:
Increased intracranial pressure
Stroke, hematoma, intracranial hemorrhage
Tumors
Infections
Demyelinating disorders
Systemic conditions affecting brain functiona. Hypoglycemiab. Fluid and electrolyte imbalances
1. Hyponatremia2. Accumulated waste products from
liver or renal failure3. Drugs affecting CNS: alcohol,
analgesics, anesthetics Seizure activity: exhausts energy metabolites
Client assessment results with decreasing LOC
Increased stimulation required to elicit response from client
More difficult to rouse; client agitated and confused when awakened
Orientation changes: loses orientation to time first; then place; finally person
Continuous stimulation required to maintain wakefulness
Client has no response, even to painful stimuli
Patterns of breathing
As respiratory center are affected: predictable changes in breathing patterns
Types of respirations and brain involvementDiencephalon: Cheyne-Stokes respirations
Midbrain: neurogenic hyperventilation; may exceed 40/minute; due to uninhibited stimulation of respiratory centers
Pons: apneustic respirations: sighing on mid inspiration or prolonged inhalation and exhalation; excessive stimulation of respiratory centers
Medulla:ataxic/apneic respirations (totally uncoordinated and irregular); loss of response to CO2
Pupillary and oculomotor responses
Predictable progression
Localized lesion effects ipsilateral pupil (same side as lesion)
Generalized or systemic processes pupils affected equally
Compression of cranial nerve III at midbrain, pupils become oval or eccentric (off center); progress to pupils become fixed (no response to light); progress to dilation
With deteriorating LOC, spontaneous eye movement is lost
Motor Function
Predictable progression Assessment of level of brain dysfunction and side
of brain affecteda. Client follows verbal commandsb. Pushes away purposely from stimulusc. Movements are more generalized and less purposeful (withdrawal, grimacing)d. Flaccid with little or no motor response
Coma States
Possible outcome of altered LOC:
Comas range from full recovery, without any
residual effects, to persistent vegetative state (cerebral death) or brain death
Stages Irreversible coma (vegetative state)
Permanent condition of complete unawareness of self and environment; death of cerebral hemispheres with continued function of brain stem and cerebellum
Client does not respond meaningfully to environment but has sleep-wake cycles and retains ability to chew, swallow, and cough
Eyes may wander but cannot track object
Minimally conscious state: client aware of environment, can follow simple commands, indicate yes/no responses; make meaningful movements (blink, smile)
Often results from severe head injury or global anoxia
Locked-in syndrome Client is alert and fully aware of environment; intact
cognitive abilities but unable to communicate through speech or movement because of blocked efferent pathways from brain
Motor paralysis but cranial nerves may be intact allowing client to communicate through eye movement and blinking
Occurs with hemorrhage or infarction of pons; disorders of lower motor neurons or muscles
Brain death
Cessation and irreversibility of all brain functions General criteria
a. Absent motor and reflex movements
b. Apnea
c. Fixed and dilated pupils
d. No ocular responses to head turning
e. Flat EEG
Prognosis
1. Outcome varies according to underlying cause and pathologic process
2. Young adults can recover from deep coma
3. Recovery within 2 weeks associated with favorable outcome
4. Prognosis is poor – lack pupilary reaction or reflex eye movement 6hr after the onset of coma
Collaborative Care
1. Management includes identifying cause, preserve function and prevent deterioration
2. Involves total system maintenance in many cases
Diagnostic Tests
1. Blood glucose: cerebral function declines rapidly
2. Serum electrolytes: hyponatremia: coma and convulsions when Na < 115 mEq/L
3. ABG: hypoxemia frequent cause of altered LOC;
4. BUN and creatinine: renal function
5. Liver function tests: tests determine liver function; high ammonia levels interfere with cerebral metabolism
6. Toxicology screening of blood and urine (acute drug or alcohol)
7. CBC: anemia or infectious cause of coma
8. CT, MRI: identification of neurologic damage
9. EEG: evaluate electrical activity of brain, unrecognized seizure activity
10. Cerebral angiography: visualization of cerebral vascular system including aneurysms, occluded vessels, tumors
11. Transcranial Doppler: assess cerebral blood flow
12. Lumbar puncture: CSF to assess infection, possible meningitis
Medications
1. IV fluids normal saline, lactated Ringer’s
2. Specific medications to address specific problems
a. 50% glucose: hypoglycemia
b. Naloxone for narcotic overdose
c. Regulation of osmolality with diuretics
d. Antibiotics: infections
Surgery May be indicated if cause of coma is tumor,
hemorrhage, hematoma
Other Measures (as indicated)1. Airway support and mechanical ventilation if
indicated
2. Maintenance of nutritional status with enteral feedings
Nursing Diagnoses
1. Ineffective Airway Clearance:
Assess ability to clear secretion
Limit suctioning to < 10 – 15 seconds;
Hyperoxygenate before
Turn from side to side every 2 hr
2. Risk for Aspiration Assess swallowing and gag reflexes every shift as
appropriate to the client’s level of consciousness
Monitor and report manifestation of aspiration
Maintain NPO
Place in the side lying position
Provide oral care and suctioning as needed
3. Risk for Impaired Skin Integrity: preventative measurescontinual inspection
4.Impaired Physical Mobility: maintain functionality of jointsphysical therapy
5. Anxiety (of family)
a. Extremely stressful time
b. Reinforce information from physician
c. Encourage to speak with client who is in coma