Sensory Perception in Nursing

Overview

Presentation on sensory perception and nursing care for sensory alterations. Covers senses, cranial nerves, disorders, assessments, age factors, and interventions.

Learning Objectives

• Identify factors and conditions affecting sensory reception and processing.
• Recognize age and developmental influences on sensory experience.
• Perform nursing assessments for sensory deficits, overload, and deprivation.
• Implement evidence-based interventions for sensory alterations.

Basic Concepts of Sensation

• Five senses: sight, smell, hearing, taste, touch.
• Sensory alteration: disruption in the function of any sense.
• Stimuli travel via sensory organs to the brain; responses are generated.
• Cranial nerves (12) transmit sensory input; dysfunction causes alterations.

Types of Sensory Alterations

• Sensory deficit: reduced function of one or more senses.
• Sensory deprivation: reduced or absent stimuli to senses.
• Sensory overload: excessive stimuli beyond brain’s processing capacity.
• Sensory processing disorder: detection intact; interpretation/response impaired.

Causes and Influences

• Age, medications, injuries, neurocognitive disorders, diseases.
• Environment (e.g., hospital lights, alarms) can cause overload.
• Developmental conditions (e.g., autism, OCD, ADHD) linked with processing issues.

Cranial Nerves: Functions and Bedside Tests

Vision Disorders

• Refractive errors:
  • Myopia: cannot see far; nearsighted.
  • Hyperopia: cannot see near; farsighted.
  • Astigmatism: corneal/lens defect; blur/distortion.
  • Presbyopia: age-related decreased near vision.
• Cataracts: lens protein clumping; blurry, hazy, decreased color, night difficulty, double vision; age/diabetes/surgeries related.
• Diabetic retinopathy: retinal vessel damage; leading adult vision loss; bilateral; early asymptomatic; spots/floaters/blurry later; requires annual exams and diabetes control.
• Glaucoma: increased intraocular pressure; optic nerve compression; first sign peripheral vision loss; irreversible; slowed by early detection (tonometry); aqueous humor buildup.
• Macular degeneration: macula degeneration; central vision loss; leading cause >65; affects reading, driving, facial recognition.

Vision Assessment and Screening

• Comprehensive eye exam; visual acuity with Snellen and tumbling E.
• Procedure: 20 feet, both eyes open, cover one eye, read smallest line; test with/without corrective lenses.
• Screening intervals:
  • Children: before first grade; every 2 years if normal.
  • Adults without disorders: every 2 years until 65, then annually.
  • With disorders: annually.

Hearing Anatomy and Disorders

• Outer ear: pinna, external canal, tympanic membrane.

• Middle ear: eustachian tube, ossicles (malleus, incus, stapes).

• Inner ear: cochlea, vestibule, semicircular canals.

• Hearing loss causes: aging, noise exposure, infection, injury, genetics.

• Tinnitus: perceived ringing/buzzing/clicking; age-related loss, injury, wax, circulatory issues.

• Sensorineural loss: inner ear or CN VIII pathology; causes include congenital, infections (measles, mumps, meningitis), noise, presbycusis, ototoxic meds; symptoms may include tinnitus, dizziness, balance issues.

• Conductive loss: transmission problem outer/middle ear; causes: trauma, inflammation, cerumen, perforation, foreign body; often treatable.

• Mixed loss: combined sensorineural and conductive.

• Otitis media: middle ear fluid/inflammation; conductive loss; treat medically.

• Otosclerosis: abnormal middle ear bone growth; gradual; often women; early to mid adulthood.

Hearing Testing and Impacts

• Audiology/ENT testing; hearing loss measured in decibels (slight to profound).
• Unrecognized loss leads to social withdrawal, isolation, depression.
• Untreated pediatric loss: speech, language, behavior, learning delays.

Speech and Language Alterations

• Aphasia: communication disorder.
  • Expressive (Broca’s): understands; cannot express desired words; frontal lobe damage; aware, frustrated.
  • Receptive (Wernicke’s): fluent but meaningless; poor comprehension; temporal lobe; unaware of incomprehensibility.
  • Global: severe; poor comprehension; cannot form words/sentences; extensive language area damage.
• Communication process: cognition, hearing, speech production, motor coordination; diaphragm/abdominal/intercostal muscles and larynx produce sound.
• Causes: injury, degenerative neurological disorders, dementia, stroke.
• Testing: history, neuro exam, MRI; referral to speech-language pathologist.

Touch Alterations

• Tactile hypersensitivity: over-responsive to touch; irritated by clothing, tags, waistbands.
• Tactile defensiveness: severe pain to non-threatening touch; avoids hugs, clothing, wind; withdraws.
• Tactile hyposensitivity: reduced pain/temperature detection; seeks touch stimulation.
• Peripheral neuropathy: peripheral nerve damage; hands/feet common; weakness, numbness, burning, tingling, temperature deficits, hyporeflexia.
• Idiopathic neuropathy: unknown cause.
• Diabetic neuropathy: chronic hyperglycemia and triglycerides damage nerves and microvasculature.

Smell (Olfaction) and Taste (Gustation)

• Interrelated; taste issues often due to smell disorders.

• Protective roles: detect smoke, gas, spoiled foods; stimulate appetite.

• Taste buds ~10,000; decline after age 50.

• Gustatory cells: receptors for sweet, sour, bitter, salty, savory; stimulated with chewing/swallowing.

• Olfactory neurons: nasal odor receptors enable smell.

• Taste disorders:

  • Phantom taste: persistent foul taste without stimulus.
  • Hypogeusia: decreased taste.
  • Ageusia: no taste.
  • Dysgeusia: persistent salty/rancid/metallic taste.

• Smell disorders:

  • Anosmia: cannot smell.
  • Hyposmia: reduced smell.
  • Parosmia: distorted odor perception; previously pleasant now unpleasant.
  • Phantosmia: smell perception without odor.

• Epidemiology: olfactory disorders affect 1.4%–62%; increase with age; more men than women.

• Causes: URIs, nasal/sinus disease, head trauma, smoking, antibiotics, antihistamines, Parkinson’s, Alzheimer’s.

• Consequences: reduced appetite, quality of life impact.

Diagnostic Testing: Sensory Systems

• Vision:
  • Refraction assessment: cornea/lens focusing; guides corrective lenses.
  • Slit lamp: microscope with bright light for anterior segment.
  • Fluorescein angiography: dye visualizes retinal vessels.
  • Amsler grid: screens macular degeneration.
• Hearing:
  • Rinne test: tuning fork on mastoid (bone vs air conduction).
  • Audiometry: headphones; tones at varying decibels.
  • Bone oscillator: mastoid vibrations; nerve response.
  • Auditory brainstem response: scalp electrodes; brain activity to sound.
  • Otoacoustic emissions: canal probe; echoes assess inner ear.
• Neuromuscular:
  • Electromyography (EMG): needles in muscle; electrical activity; nerve damage detection.
  • MRI: confirm structural causes.
• General: physical exam, history; ENT referrals; imaging as indicated.

Age and Other Factors Affecting Sensory Perception

• Aging:
  • Need stronger stimuli; hearing and vision most affected.
  • Hearing: high-frequency loss; difficulty differentiating sounds.
  • Vision: less sensitive corneas; smaller, less reactive pupils; reduced acuity; less flexible lenses; weaker extraocular muscles; color discrimination issues (blue/green); decreased peripheral vision; floaters.
  • Taste and smell: diminished sour, sweet, bitter detection; odor detection declines; reduced appetite and nutrition risk.
• Medications: side effects include dry mouth; altered taste/smell; ototoxicity.
• Neurocognitive disorders: dementia, delirium cause neuronal loss; delirium is multifactorial, reversible, often misdiagnosed.

Nursing Interventions and Education

• Priorities: safety, independence, emotional support.
• General:
  • Provide education; ensure proper equipment; adapt environments for safety.
• Vision:
  • Annual exams; healthy diet; control blood glucose and blood pressure.
• Hearing:
  • Preventive education on noise exposure and protective equipment.
  • Manage headphone volumes; workplace hearing protection.
  • Communicate facing the client; adequate lighting; check hearing aids; speak slowly and clearly.
• Speech:
  • Allow extra time; avoid interruptions; do not speak for clients.
  • Consider assistive devices (e.g., voice box post-laryngectomy).
• Touch:
  • Prevent spinal cord harm; minimize fall risk; appropriate equipment.
  • Foot care; diabetes education for neuropathy prevention.
• Smell/Taste:
  • Dental hygiene; maintain smoke and CO detectors.
  • Discuss smoking cessation.

Key Terms & Definitions

• Sensory deficit: loss of expected function of a sense.
• Sensory deprivation: reduced/absent sensory input.
• Sensory overload: excessive stimuli beyond processing capacity.
• Presbyopia: age-related near vision decline.
• Presbycusis: age-related hearing loss.
• Tinnitus: perception of sound without external source.
• Otitis media: middle ear fluid/inflammation.
• Otosclerosis: abnormal middle ear bone growth.
• Aphasia (expressive, receptive, global): language impairments by brain region.

Action Items / Next Steps

• Screen patients per age and risk: vision and hearing schedules.
• Educate clients with diabetes on eye exams and glycemic control.
• Assess environments for sensory overload; modify as needed.
• Use standardized bedside cranial nerve tests during assessments.
• Refer to specialists (ENT, audiology, ophthalmology, SLP) when indicated.