Cognitive and Sensory Alterations Notes

Chapter 31: Cognitive and Sensory Alterations

Normal Structure and Function of Brain and Body Regions

• Cognition: Influenced by awareness and judgment.
• Sensation: A feeling, within or outside the body, resulting from stimulation of sensory receptors.
• Perception: The way the brain perceives information.
• Reticular Activating System (RAS): The area of the brain that controls alertness and attention.
• Sensory Adaptation: The brain’s process of filtering impulses by priority during times of alertness.
• General Senses:
  • Touch, pressure, temperature, and pain.
  • Tactile receptors are located in the dermis and subcutaneous tissue.
• Special Senses:
  • Smell: Chemoreceptors in the upper nasal passages.
  • Taste: Chemoreceptors in the taste buds on the tongue, the roof of the mouth, and the throat.
  • Hearing: Occurs through the workings of the outer, middle, and inner ears.
  • Equilibrium: Receptors in the ear’s semicircular canal.
  • Vision: Photoreceptors in the eye’s retina.

Alterations in Structure and Function Associated with Impaired Cognition and Sensation

• Aging:
  • Number of neurons decreases.
  • Gradual decline in the ability to interpret sensory stimuli.
  • Slower response time.
  • Judgment, language, or the ability to live independently are generally not affected.
• Cognitive Alterations:
  • Delirium:
    • Signs and symptoms: fluctuating awareness, impairment of memory, disorganized thinking, hallucinations, and disturbances of sleep-wake cycles.
  • Depression:
    • Signs and symptoms: loss of interest, sadness for an extended period, decreased self-esteem, sleeping too much or insomnia, and changes in eating patterns.
  • Dementia:
    • Decline in many cognitive abilities.
  • Alzheimer's Disease: A specific type of dementia characterized by progressive cognitive decline.
  • Cerebrovascular Accident (CVA):
    • Also known as a stroke, it can cause various cognitive impairments.
    • Aphasia: Language impairment caused by CVA or other brain damage.
  • Meningitis: Inflammation of the meninges, which can lead to cognitive alterations.
  • Brain injuries and illnesses can also impair cognition.
• Sensory Deficits:
  • Tactile: Peripheral neuropathy.
  • Smell: Anosmia (loss of sense of smell).
  • Taste: Decreased gustatory cells.
  • Hearing:
    • Conductive hearing loss.
    • Sensorineural hearing loss.
    • Presbycusis (age-related hearing loss).
  • Equilibrium:
    • Motion sickness.
    • Ménière’s disease.
  • Vision:
    • Myopia (nearsightedness).
    • Presbyopia (age-related farsightedness).
    • Cataracts.
    • Glaucoma.
    • Diabetic retinopathy.
    • Macular degeneration.
• Sensory Deprivation:
  • A person who cannot see, hear, feel, or respond to the environment may feel socially isolated.
  • Symptoms: patient may appear bored, restless, and disinterested with a decreased ability to think.
• Sensory Overload:
  • An overabundance of stimuli.
  • When the brain is overly stimulated, it ceases to make sense of the incoming stimuli.
  • Symptoms: anxiety, attention deficit, and confusion.

Assessment

• Health History:
  • Effects of lifestyle on cognition and sensation.
    • Smoking, obesity, a high-cholesterol diet, and excessive alcohol use: hypertension and increased risk of stroke.
    • Cocaine use: decreased sense of smell.
    • Smoking: decreased senses of smell and taste.
    • Stress: hypertension.
    • Metabolic syndrome: patient is at a higher risk for developing sensory deficits due to associated diseases.
    • Lack of sleep: impaired concentration, judgment, and mental abilities; blurred vision and decreased response to auditory stimuli.

Nursing Diagnosis Examples

• Chronic Confusion:
  • Supporting Data: Alert and oriented to person only; unable to express his needs but repeats questions asked, or responds with unrelated comments; wife states patient wanders frequently.
• Impaired Verbal Communication:
  • Supporting Data: Alterations of the central nervous system, cerebrovascular accident (CVA), inability to recognize words or understand questions.
• Risk for Social Isolation:
  • Supporting Data: Alterations in mental status, dementia, sad affect, states “I feel so alone”.

Implementation and Evaluation

• Patients with Cognitive Alterations:
  • Orient to person, place, and time.
  • Maintain a safe environment.
  • Keep communication clear and simple.
  • Provide reminders for or assistance with self-care.
• Patients with Tactile Alterations:
  • Test the temperature of bath water.
  • Monitor extremities frequently.
  • Turn and reposition patients who are unable to move in bed independently at least every 2 hours.
  • Keep sharp objects away from the affected area.
• Patients with Olfactory and Gustatory Alterations:
  • Encourage intake of a well-balanced diet.
  • Serve highly aromatic foods.
  • Remain diligent about oral hygiene.
  • Encourage patients to eat a variety of foods and enhance flavor with spices and herbs.
• Patients with Auditory Alterations:
  • Encourage patients with hearing aids to use them in the hospital.
  • Keep hearing aid in working order and prevent loss.
  • Face the patient when speaking.
  • Speak clearly and slowly without shouting.
  • Minimize background noise.
  • Use written instructions, if practical.
  • Use a sign language interpreter, as needed.
  • Use in-room technology to assist with communication.
• Patients with Equilibrium Alterations:
  • Instruct patient to call for assistance when ambulating.
  • Keep a basin on the bedside stand for patients experiencing nausea or vomiting.
  • Keep the lights dim and minimize noise.
  • Keep the floor clear of obstacles.
• Patients with Visual Alterations:
  • Orient patient to placement of items in the hospital room.
  • Keep call light and assistive devices within reach.
• Patients with Sensory Deprivation:
  • Provide social interaction and tactile stimulation.
• Patients with Sensory Overload:
  • Reduce sensory stimuli.
• Evaluation:
  • Conduct ongoing evaluation of goal attainment.
  • Update the care plan and set new goals.
  • Include the patient and family when evaluating the plan of care.