Cognitive and Sensory Alterations Notes

Cognition and Sensation

• Cognition: Knowing influenced by awareness and judgment.

• Sensation: A feeling, within or outside the body, of conditions 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 Cognition and Sensation

• Aging:

  • Number of neurons decrease.

  • Gradual decline in the ability to interpret sensory stimuli.

  • Slower response time.

  • Judgment, language, and the ability to live independently are generally unaffected.

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

• Cerebrovascular accident (CVA):

  • Aphasia: inability to speak

• Meningitis

• Brain injuries and illnesses

Sensory Deficits

• Tactile: peripheral neuropathy (weakness, numbness, and pain from nerve damage, usually in the hands and feet).

• Smell: anosmia (loss of smell).

• Taste: decreased gustatory cells (specialized receptor cells within taste buds that are responsible for detecting taste).

• Hearing: conductive hearing loss, sensorineural hearing loss, presbycusis (hearing loss in both ears).

• Equilibrium: motion sickness and Ménière’s disease.

• Vision: myopia (nearsightedness), presbyopia (farsightedness), cataracts (cloudiness of the eye), glaucoma ( eye condition that damages the optic nerve), diabetic retinopathy (diabetes that affects the eyes), and macular degeneration (causes loss in the center of the field of vision).

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.

Implementation and Evaluation: 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.

Implementation and Evaluation: 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.

Implementation and Evaluation: 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.

Implementation and Evaluation: 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.

Implementation and Evaluation: Patients with Visual Alterations

• Orient patient to placement of items in the hospital room.

• Keep call light and assistive devices within reach.

Implementation and Evaluation: Patients with Sensory Deprivation

• Provide social interaction and tactile stimulation.

Implementation and Evaluation: 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.