• Sensory stimuli give meaning and order to events occurring in the environment.
• Sight, hearing and balance, touch, olfactory, taste, ability to speak

• Reception
• Perception
• Reaction

• reception begins with stimulation of a nerve cell called a receptor, which is usually designed for only one type of stimulus.  The nerve impulse travels along pathways to the spinal cord or directly to the brain.

• when the person becomes conscious of the stimuli and receives the information, perception has occurred.  Perception includes integration and interpretation.  Factors affecting consciousness affect perception, ie, blurred vision or lack of understanding

• a person cannot react to all stimuli bombarding the nervous system.  The brain discards or stores some sensory stimuli.  A person reacts to stimuli that are meaningful or significant at that time.  After continued reception of a stimulus, a person may fail to respond to it at all.

Sensory Alterations

• Sensory Deficit

Sensory Deprivation

• Sensory Overload

• Sensory Deficit

Sensory deficit is a deficit in the normal function of sensory reception and perception.  A person may not be able to receive stimuli (ie, deaf, blind) or stimuli may become distorted (ie, blurred vision.)  When senses are impaired, the sense of the self is impaired.  The person may withdraw in an effort to cope.  It is difficult for the person to interact with the environment.  Safety is a concern.  After time the person may develop adaptive or maladaptive ways of dealing with the deficit.

• Sensory Deprivation

When a person experiences an inadequate quality or quantity of stimulation, sensory deprivation occurs.  Those most at risk are those living in a confined environment, such as a nursing home. 

The effects of sensory deprivation are varied, including:  inability to think or learn, disorientation, restlessness, increased anxiety, impaired visual/motor coordination.  Many patients with sensory deprivation are treated for psychological problems.  Be aware that these behaviors could have many causes, and be careful to fully assess patients.

Sensory overload results when a person receives multiple sensory stimuli and cannot disregard or ignore some stimuli.  Excessive stimulation prevents the brain from appropriately responding to or ignoring certain stimuli.  Because the multitude of stimuli leads to overload, the person can no longer perceive the environment in a meaningful way.  Overload is individualized.  The amount of stimuli needed for health function varies with each individual.  A person’s tolerance to sensory overload may vary by level of fatigue, attitude, and emotional/physical well being.  In a hospital setting, the behavioral changes associated with sensory overload can easily be attributed to mood swings or simple disorientation.

Sensory overload is common in the hospital.  What nursing actions are appropriate if a patient in the hospital is experiencing sensory overload?  Provide the patient with periods of rest and offer short repeated explanations.

Factors that influence sensory function

• Age

o       Vision

The most common visual problem is refractive error.

Myopia (nearsightedness) is the most common.

                        Visual changes associated with aging:

Decreased visual acuity

Decreased accommodation

Presbyopia

Need for reading glasses

Reduced depth perception

Increased glare sensitivity

Impaired night vision

Reduced color discrimination (perception of blue, violet, green declines)

Etiology, pathophysiology, and nursing management of the patient with a cataract

Etiology, pathophysiology, and nursing management of the patient with glaucoma

Factors that influence sensory function

• Age

o       Hearing

Decreased hearing acuity is associated with aging.

Symptoms of hearing loss:

            Patient seems inattentive to others

            Patient responds with inappropriate anger when spoken                                to

            Patient believes people are talking about him/her

            Patient has trouble following clear directions

            Patient asks to have something repeated

            Patient has monotonous or unusual voice quality and                                    speaks in a loud or soft tone

            Patient has TV unusually loud

Hearing loss

Hearing loss occurs in the outer and middle ear; impairs the sound being conducted from the outer to the inner ear.

Causes:  foreign bodies, middle ear disease, impacted cerumen.  

With aging, cerumen thickens and builds up in the ear canal.  Excessive cerumen is a common cause of conductive hearing loss in the elderly.

– Hearing loss is caused by impairment of function of the inner ear or its central connections. 

Causes:  noise trauma over a period of time, ototoxicity, aging (presbycusis)

Changes associated with aging:

• Decrease in number of taste buds
•             Reduced taste discrimination

o       Tactile changes

Changes associated with aging:

Declining sensitivity to pain, pressure, and                                        temperature

o       Proprioceptive changes

Changes associated with aging:

Increased difficulty with balance, spatial orientation, and coordination

• Medications

•  
  • Ototoxity of some medications such as the aminoglycosides (gentamycin, tobramycin, etc) – damage the auditory nerve.  These drugs have a narrow window of therapeutic range.  Monitor patients closely for tinnitus/hearing loss.  Monitor peak and trough levels. 
  • Medications that alter the perception of stimuli (narcotic analgesics, sedatives, etc)

·         Meaningful stimuli

o       Meaningful stimuli reduce sensory deprivation

o       Pets, music, television, pictures of family members, calendar/clock

·         Amount of stimuli

o       Excessive stimuli can cause sensory overload

• Environmental factors

o       Excessive stimuli can result in sensory overload:  confusion, disorientation, inability to make decisions

o       Restricted stimuli can lead to sensory deprivation

• Social interaction

o       Social isolation/lack of meaningful interactions can lead to sensory changes

Assessment of the Sensory System

• Persons at risk

• Mental status

Observe the patient during history taking, physical exam, and during delivery of care.  Look for signs of sensory deprivation or overload.

• Physical assessment

Assess visual acuity, recommend professional eye exam

Assess hearing and balance

Assess olfaction

Assess taste

Assess the ability to discriminate light touch, temperature, pain, and            position

• Ability to perform self care

Assess functional abilities including feeding, dressing, grooming, and toileting activities

•  
  • Ask the patient to describe the sensory deficit:  Tell me about your hearing loss.
  • How has the patient adjusted to the alteration?
  • How long has the patient had the problem?
  • Ask the patient to self assess their alteration:  Rate your hearing as excellent, good, fair, poor, or bad.  This allows the nurse to more fully explore the client’s perception of the sensory loss.
  • Ask the patient or family member about any recent changes in the patient’s behavior.

• Health promotion habits

o       Assess the patient’s daily routines related to sensory function.

Is there exposure to noise?  Participation in sports?  Work related hazards? 

o       The patient’s last health screening

• Hazards in the environment

Nursing Diagnosis

• Risk for injury
• Impaired verbal communication
• Self care deficit
• Mobility, impaired physical
• Social isolation – a state in which an individual perceives a need for increased involvement with others but is unable to make that contact

Examples of patient goals

• The patient will be able to shower independently within 7 days. 
• The patient will interact within a safe environment and will have no injury during hospitalization. 

Plans/Implementation

• Plans relating to Health Promotion.

Vision

•  
  • Adults over the age of 40 should have eye exams (to include measurement of intraocular pressure) at least every two years.  After age 65, adults should have an exam annually.
    • Glaucoma is the second leading cause of blindness in the general population, and the primary cause of blindness in African-Americans.  Glaucoma is characterized by: increased intra-ocular pressure, optic nerve atrophy, and peripheral visual field loss.  Blindness is largely preventable with early detection and treatment.  Glaucoma develops slowly, with no symptoms of pain or pressure.  The patient does not notice the gradual field loss until vision has been severely compromised.

•  
  • Adults over the age of 40 should have a routine hearing assessment as part of their annual physical exam. 

• Plans relating to preventive safety

o       Trauma is a common cause of blindness in children.

o       Adults are at risk while playing sports or working in jobs involving exposure to chemicals or flying objects. 

o       Hearing loss can be prevented by wearing ear plugs.

• Plans related to communication

•  
  • The hearing impaired patient

Hearing loss due to aging is called presbycusis.  Vowels are heard, but consonants and other high frequency sounds cannot be differentiated.  To communicate with someone with presbycusis, lower the tone of the voice and face the person.

Others that are hearing impaired read lips or use sign language. 

Hospitals are required to make translators available.

o       The vision impaired patient

Use of voice, use of Braille

o       – unable to produce or understand language

Aphasia – the most common language disorder following a stroke.  The inability to communicate can be frustrating and frightening.  Aphasia does not reflect intellectual impairment or degeneration of personality. 

§         Expressive aphasia is the inability to name common objects or to express simple ideas in words or writing

§         Receptive aphasia is the inability to understand written or spoken language.  The patient may be able to express words but is unable to understand questions or comments of others.

§         Communication Methods, for patients with aphasia

1.      Listen to the patient and wait for the patient to communicate.

2.      Do not shout or speak loudly.

3.      If the patient has problems with comprehension, use simple, short questions and facial gestures to give additional clues.

4.      Speak of things familiar and of interest to the patient.

5.      If the patient has problems speaking, ask questions that require simple yes or no answers.  Offer pictures or a communication board.

6.      Give the patient time to understand.

7.      Be calm and patient.

8.      Do not pressure or tire the patient.

9.      Avoid patronizing and childish phrases.

• Plans relevant to the hospital setting

§         When caring for a patient with a sensory deficit, always announce your presence when entering the patient’s room.  Speak before touching the patient to avoid startling him or her.  Tell the patient when you leave the room.

§         Use short, simple, repeated explanations and frequent reassurance.

§         Orient the patient thoroughly to the environment.

§         Be sure the patient has a call bell that they can use.

§         Necessary objects should be placed in front of the patient, to avoid leaning over the rail.

§         Maintain consistency in the environment. The environment should be safe and promote independence.

§         Side rails help promote safety and security.

§         Remember that bed-ridden patients are at risk for sensory deprivation.

• Plans related to patient education

o       Teaching booklets available in large print

o       Booklets available in Braille

o       Frequent, simple verbal instructions

o       Audiotapes

o       Visual teaching aids

• Plans related to maintaining a healthy lifestyle

o       Helping patients understand the implications of the loss

o       Helping patients adjust positively to the loss

o       The role of family and friends as support persons

o       The importance of socialization

o       The importance of promoting self care

Evaluation

• The patient is the source of data to use in evaluating outcomes.