Nursing 280: Pathophysiology Module V: Alterations in Central Nervous System Function and Special Se

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Nursing 280 PathophysiologyModule V
Alterations in Central Nervous System Function
and Special Sensory FunctionPart B Pain and
Neurologic Dysfunction Evaluation

• Presented by
• Ronda M. Overdiek, M.S.N., R.N.

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Part B Pain and Neurologic Dysfunction Evaluation

• Study Guide Objectives 5-7
• Chapter 13
• Chapter 14

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Part B PainObjectives

• 5 Describe pain and differentiate between the
  various types of pain
• 6 Describe the mechanisms of pain
• 7 Discuss concepts of neurologic dysfunction
  with relation to pathophysiology, clinical
  manifestations, and evaluation.

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Objective 5Describe pain and differentiate
between the various types of pain.

• Pain
• Complex phenomenon composed of sensory
  experiences that include time, space, intensity,
  emotion, cognition, and motivation.
• Unpleasant phenomenon that is uniquely
  experienced by each individual
• Cannot be adequately defined, identified or
  measured by an observer.

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Objective 5Describe pain and differentiate
between the various types of pain.

• Pain must be evaluated continuously
• The 5th vital sign
• Joint Commission on the Accreditation of
  Healthcare Organizations (JCAHO)
• Pain scales according to facility
• Harmful effects of pain
• Impairs patients ability to sleep
• Acute pain The stress response
• Chronic pain Suppression of immune
  function-promote tumor growth
• Depression, anger, fatigue, anxiety
• Purpose of pain
• Protective mechanism for the body
• Occurs when tissues are being damaged
• Causes an individual to react to remove pain
  source

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Objective 5Describe pain and differentiate
between the various types of pain Acute

• Pain Functionally Divided
• Acute
• Protective mechanism that alerts the individual
  to a condition or experience that is immediately
  harmful to the body.
• Onset sudden
• Discontinues after chemical mediators that
  stimulate nociceptors are removed.
• Associated with anxiety
• Arises from somatic or visceral structures

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Objective 5Describe pain and differentiate
between the various types of pain Acute

• Classifications
• Somatic
• Superficial (skin/close to the surface of the
  body)
• Either sharp/well localized or dull, aching, and
  poorly localized
• Accompanied by nausea/vomiting
• Carried by sensory nerves

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Objective 5Describe pain and differentiate
between the various types of pain Acute

• Classifications
• Visceral Pain
• Pain in the internal organs, abdomen, skeleton
• Poorly localized and associated w/nausea and
  vomiting, hypotension, restlessness, shock.
• Radiates or is referred
• Carried by sympathetic nerve fibers

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Objective 5Describe pain and differentiate
between the various types of pain Acute

• Classifications
• Referred Pain
• Present in an area removed or distant from its
  point of origin.
• Area of referred pain is supplied by the same
  spinal segment as the actual site of pain
• Brain cannot distinguish origin
• Figure 13-4 Page 333.

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Objective 5Describe pain and differentiate
between the various types of pain Chronic

• Chronic
• Persistent (usually lasting at least 3-6 months)
• Cause is usually unknown if known it will not
  respond to conventional therapies
• Individuals usually experience more suffering
  over time
• Sense of hopelessness and helplessness, can cause
  depression
• Table 13-2 Page 334

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Objective 5Describe pain and differentiate
between the various types of pain.ACUTE VS
CHRONIC(Table 13-3, page 334)

• Experience
• Source
• Onset
• Duration
• Pain Identification
• Clinical Signs

• Significance
• Pattern
• Course
• Actions
• Prognosis

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Objective 5Describe pain and differentiate
between the various types of pain.

• Classes of Pain
• Somatogenic
• Pain with a cause
• Psychogenic
• Pain for which there is no known physical cause
• NOT imaginary

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Objective 5Describe pain and differentiate
between the various types of pain.

• Pain Terms
• Pain Threshold Point at which a stimulus is
  perceived as pain
• Hyperalgesia A decrease in pain threshold in an
  area of inflammation such that even trivial
  stimuli can cause pain.
• Caused by release of chemical mediators from
  injured cells, i.e., arachidonic acid and
  bradykinins
• Pain Tolerance It is the amount of pain the
  person will tolerate before outwardly responding
  to it.

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Objective 6Describe the mechanisms of pain

• Portions of nervous system responsible for pain
• Afferent pathways
• Nociceptors (pain receptors)
• Central Nervous System
• Interpreting pain signals
• Limbic system, reticular formation, thalamus,
  hypothalamus, medulla, cortex.
• Efferent pathways
• Modulating pain sensation

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Objective 6Describe the mechanisms of pain

• Nociceptors
• Pain receptors located in skin, skeletal
  structures, viscera
• Transduce mechanical, thermal, or chemical
  stimuli into action potentials that are
  transmitted along their axons to the spinal cord
• Cell bodies of the nociceptors are located in the
  dorsal root ganglia
• They synapse in the dorsal horn of the spinal
  cord with interneurons or projection neurons that
  carry the information to higher centers in the
  brain stem and thalamus

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Objective 6Describe the mechanisms of pain

• Nociceptors
• Naked, afferent nerve endings of two different
  types of fibers
• A-delta myelinated fibers
• C fibers (unmyelinated)
• Fibers encode the occurrence, intensity,
  duration, and location of noxious stimuli and
  signal pain sensation

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Objective 6Describe the mechanisms of pain

• A-delta fibers
• Myelinated, transmission is quick
• Carry well-localized, sharp pain sensations
• Fast pain neospinothalamic tract
• Projects to the posterior portions of the
  thalamus
• Considered to be involved with spatial and
  temporal aspects of pain perception
• C Fibers
• Unmyelinated transmission is slow
• Transmission of diffuse burning or aching
  sensations
• Slow pain paleospinothalamic tract
• Projects to the medial thalamus
• Responsible for the initiation of unpleasant
  aspects of pain as well as the autonomic nervous
  system responses to pain

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Objective 6Describe the mechanisms of pain
Page 331
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Objective 6Describe the mechanisms of pain

• Modulation of Pain
• Tissue injury results in release of PGE,
  bradykinins, histamine, etc. which depolarize
  adjacent nociceptors causing pain.
• Pain receptors release substance P and neurokinin
  A, promoting the spread of pain locally.
• Inhibitors
• Endorphins (enkephalins) attach to opiate
  receptors on the plasma membrane of the afferent
  neuron, inhibiting the release of excitatory
  neurotransmitters such as substance P.

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Objective 7Discuss concepts of neurologic
dysfunction

• Assessment of dysfunction
• Consciousness
• Breathing pattern
• Pupillary responses
• Occulomotor responses
• Motor responses

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Objective 7Discuss concepts of neurologic
dysfunction

• Consciousness
• Involves
• Arousal state of awakeness, mediated by
  reticular activating system.
• Content of thought encompasses all cognitive
  functions, including awareness of self,
  environment, and affective states (moods)
• Level of consciousness
• Most critical clinical index of nervous system
  function
• Indication of improvement or deterioration in
  patient condition
• Table 14-3 Page 348

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Objective 7Discuss concepts of neurologic
dysfunction

• Breathing Pattern
• Assist in evaluating the level of brain
  dysfunction and coma
• Rate, rhythm, and pattern
• Table 14-4 Page 349

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Objective 7Discuss concepts of neurologic
dysfunction

• Pupillary Responses
• Brain stem areas that control arousal are
  adjacent to areas that control pupils.
• Changes in pupils are a valuable guide to
  evaluating the presence and level of brain stem
  dysfunction
• Drugs can cause dilation or constriction
• Ischemia/hypoxia produce bilaterally wide and
  fixed pupils in most instances

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Objective 7Discuss concepts of neurologic
dysfunction

• Oculomotor Responses
• Change with various degrees of brain dysfunction
• Oculocephalic reflex response (dolls eyes
  phenomenon)
• Figure 14-3 page 360
• Oculovestibular Reflex
• Figure 14-4 page 361

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Objective 7Discuss concepts of neurologic
dysfunction

• Motor responses
• Evaluate the level of brain dysfunction and
  determine the most severely damaged side of the
  brain.
• Pattern (Reflexes)
• Purposeful
• Inappropriate, generalized movement
• Not present

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Objective 7Discuss concepts of neurologic
dysfunction

• Posturing
• Decorticate
• Decerebrate

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Objective 7Discuss concepts of neurologic
dysfunction