UNCONCIOUS AND COMA

CNH

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