Transcript document

Health Psychology
Chapter 13:
Managing Pain
Nov 30- Dec 5, 2007
Classes #40-42
What is pain?
A sensory and emotional experience
of discomfort.
 Single most common medical
complaint.

Components of Pain
PHYSIOLOGY
BEHAVIORAL
SENSORY
PAIN
COGNITIVE
AFFECTIVE
Three Broad Categories of Pain

Acute pain is a useful biological
response provoked by injury or disease,
which is of limited duration
Sharp, stinging pain usually localized in an
injured area of the body
 Usually subsides after normal healing


Recurrent is acute pain occurring
periodically (e.g. migraine)

Discomfort and pain-free periods
Nociceptive (“good”) pain
•Requires a potentially noxious stimuli.
•Protective function (preserves tissue integrity).
brief
Acute (brief)
injury
CNS
Pain
Chronic Pain

Is described as pain persisting for six
months or more and tends not to respond
to pharmacological treatment
 Lowers overall quality of life
 Increases vulnerability to infections and
disease
• Hyperalgesia
Hyperalgesia
An extreme sensitivity to pain, which in one
form is caused by damage to nociceptors in
the body's soft tissues.
 “Irritable Focus”

Hyperalgesia
Primary hyperalgesia describes pain
sensitivity that occurs directly in the
damaged tissues
 Secondary hyperalgesia describes
pain sensitivity that occurs in
surrounding undamaged tissues

Definitions
 Hyperalgesia:
increased pain
response to a painful stimulus
in
 Allodynia:
pain in response to an
innocuous stimulus
 Spontaneous
pain: pain
absence of a stimulus
in
the
PHYSIOLOGY OF PAIN
Perceiving Pain
Algogenic substances – chemicals
released at the site of the injury
 Nociceptors – afferent neurons that
carry pain messages
 Referred pain – pain that is perceived
as if it were coming from somewhere
else in the body

Peripheral Nerve Fibers
Involved in Pain Perception
A-delta fibers – small, myelinated
fibers that transmit sharp pain
 C-fibers – small unmyelinated nerve
fibers that transmit dull or aching pain.
 A-delta fibers

Pain without apparent physical
basis…
Persists long after healing
 May spread and increase in intensity
 May become stronger than was the initial
pain from the injury

Three Chronic Pain Conditions
Neuralgia – an extremely painful condition
consisting of recurrent episodes of intense
shooting or stabbing pain along the course of
the nerve.
 Causalgia – recurrent episodes of severe
burning pain.
 Phantom limb pain – feelings of pain in a limb
that is no longer there and has no functioning
nerves.

THEORIES OF PAIN

In this lecture, we will consider three
theories of pain:
Specificity Theory
Pattern Theory
Gate Control Theory
Specificity Theory (Von
Frey, 1894)

This theory describes a direct causal
relationship between pain stimulus and pain
experience.
BRAIN
• Stimulation of specific pain receptors (nociceptors)
throughout the body, sends impulses along specific
pain pathways (A-delta fibres and C-fibres) through
the spinal cord to specific areas of the sensory cortex
of the brain.
•Stimulus intensity correlates with pain intensity;
higher stimulus intensity and pain pathway activation
resulting in a more intense pain experience.
NOCICEPTORS
•Failure to identify a specific cortical location for pain,
realisation that pain fibres do not respond exclusively
to pain but also to pressure and temperature, and the
disproportional relationship between stimulus intensity
and reported pain intensity.
Pattern Theory



Pattern theorists proposed stimulation of nociceptors
produces a pattern of impulses that are summated in the
dorsal horn of the spinal cord.
Only if the level of the summated output exceeds a certain
threshold is pain information transmitted onwards to the
cortex resulting in pain perception.
Evidence of deferred pain perception raised questions
concerning the comprehensiveness of pattern theories:
Soldiers not perceiving pain until the battle is over
Phantom limb
Injury without pain perception

There was growing evidence for a mediating role for
psychosocial factors in the experience of pain, including
cross-cultural differences in pain perception and expression.
Gate-Control Theory –
Ronald Melzack (1960s)
Described physiological mechanism by which
psychological factors can affect the
experience of pain.
 Neural gate can open and close thereby
modulating pain.
 Gate is located in the spinal cord.

Gate-Control Theory
Gate is closed
Gate is open
Brain
Brain
To
brain
From
pain
fibers
Gating
Mechanism
From
other
Peripheral
fibers
Transmission
Cells
Spinal Cord
To
brain
From
pain
fibers
Gating
Mechanism
From
other
Peripheral
fibers
Transmission
Cells
Spinal Cord
Three Factors Involved in
Opening and Closing the Gate
The amount of activity in the pain
fibers.
 The amount of activity in other
peripheral fibers
 Messages that descend from the
brain.

Conditions that Open the Gate

Physical conditions
Extent of injury
 Inappropriate activity level


Emotional conditions
Anxiety or worry
 Tension
 Depression


Mental Conditions
Focusing on pain
 Boredom

Conditions That Close the Gate

Physical conditions
Medications
 Counter stimulation (e.g., heat, message)


Emotional conditions
Positive emotions
 Relaxation, Rest


Mental conditions
Intense concentration or distraction
 Involvement and interest in life activities

Psychosocial Factors
Age
 Gender
 Significant Others/Family Members
 Mood
 Stress

Gender: Who deals with pain
better???



Men or Women???
 Biology, sex hormones, culture, socialization and
role expectations, psychology, and past experience
have been offered as explanatory variables.
 However, the relationship between pain and gender
is complex.
The particular type of pain, when it occurs, and the
researcher’s gender are all implicated in pain reporting.
Skevington (1995) argues gender differences may have
been overemphasized and significant similarities exist
between the sexes regarding pain experiences and
actual differences may relate to treatment behavior and
pain severity.
Age






The experience of pain has been found to vary across the lifespan.
Less is known about pain in children than in adults.
Chronic pain in children appears to be under represented in the pain
literature, despite the reporting of both persistent and recurring
chronic pain by children.
For older adults, pain may be a pervasive aspect of their lives differing
qualitatively from that experienced by younger age groups.
The elderly are also consistently under-represented in the pain
literature and pain in this group is substantially under-diagnosed and
under-treated.
Health psychologists should work to improve diagnostic techniques
and understanding of the pain across the lifespan, especially among
children, older adults and the way it interacts with other aspects of
their lives.
Significant others and the
family





A common concept in chronic pain research is that subjective pain
and pain related behaviour may be affected by significant others
who are perhaps one of the major reinforcers for pain-related
behaviours and chronicity.
Spousal solicitousness may inadvertently maintain or increase the
experience of pain and disability.
Parents are the most significant influence on a child’s pain
perception, modeling behaviours as well as reinforcing them.
Pain within the family is likely to affect all family members and the
family will affect how they all cope.
Further research is required with measurement instruments
specifically developed to assess the relevant variables in pain
populations need to be extended to include families and significant
others.
Pain-prone personality

Engel (1959)


Features of the pain prone personality include continual
episodes of varying chronic pain, high neurotic
symptoms (guilt feelings, anxiety, depression and
hypochondria)
Generally, empirical support for the pain-prone
personality has not been forthcoming and it has been
suggested that the higher scores for particular
personality factors (i.e. neurotic triad) may be a
consequence rather than a cause of long-term pain.
Mood

There is a relationship between pain and anxiety



Acute pain increases anxiety. But once pain is decreased through
treatment, the anxiety also decreases, which can cause further decreases
in the pain, a cycle of pain reduction.
Chronic pain remains unalleviated by treatment and therefore anxiety
increases which can further increase the pain, creating a cycle of pain
increase.
Depression is also commonly associated with pain.
People who experience severe and persistent pain
often have feelings of hopelessness, helplessness and despair.

While correlations between mood states and pain have been found, the
causal direction and the nature of the relationships remains unclear.
Stress




Chronic pain both exacerbates and is exacerbated by stress.
Experiencing persistent high levels of pain can itself can be a
substantial stressor, possibly even the most significant stressor in the
lives of many individuals.
It is also often the source of additional life stresses, like loss of
employment, relationship difficulties and financial hardship.
Individual, stereotypical physiological responses to stress (e.g.
clenching jaws, migraine headaches) can be a direct source of pain
and the physiological arousal associated with stress may lead to
increased pain and inhibit effective adaptation.
Stress is such a frequent concomitant of pain that stress
management techniques are routinely included as an integral part
of pain management programmes.
SOCIOCULTURAL
INFLUENCES ON PAIN





Pain experience is expressed differently across cultural
groups.
Social learning influences pain tolerance levels,
communication about pain, pain behaviours and the
meaning of pain.
Cultural influences may encourage avoidance or
acceptance of pain, demonstrable pain behaviours or
stoic concealment.
It may also affect the treatment received within
healthcare systems in terms of cultural expectations and
communication traditions.
Further research is needed on the influence of social
factors and discrimination on the experience of pain
treatment for minority groups.
Treatment of Chronic Pain

Surgical procedures to block the
transmission of pain from the peripheral
nervous system to the brain.

Synovectomy
• Removing membranes that become inflamed in
arthritic joints

Spinal fusion
• Joins two or more adjacent vertebrae to treat
chronic back pain
Pharmacologic Control of Pain
About half of hospitalized patients who have
pain are under-medicated.
 Children are at particular risk of poor pain
control methods.
 Medications are given as:

PRN – “as needed”
 As a prescribed schedule

Types of Pain Medications

Peripherally active analgesics


Centrally active analgesics


Narcotics that bind to the opiate receptors in the brain
(e.g., codeine, morphine, heroin).
Local analgesics


Work at the periphery (e.g., aspirin, Tylenol).
Can be injected into the site of injury or applied
topically (e.g., novocaine).
Indirectly acting drugs

Affect non-pain conditions such as emotions that can
exacerbate pain experience.
Transcutaneous Electrical
Nerve Stimulation

T.E.N.S.
Replace pain impressions with massage-like
sensations
 Athletes, elderly among others

Psychological Pain Control Methods

Biofeedback


Relaxation


Provides biophysiological feedback to patient
about some bodily process the patient is
unaware of (e.g., forehead muscle tension).
Systematic relaxation of the large muscle
groups.
Hypnosis

Relaxation + suggestion + distraction + altering
the meaning of pain.
Psychological Pain Methods

Acupuncture

We’re not exactly sure how it works. Could
include:
• Counter-irritation as it may close the spinal gating
mechanism in pain perception
• Expectancy
• Reduced anxiety from belief that it will work
• Distraction
• Trigger release of endorphins
Cognitive-Behavioral Therapy

Multidisciplinary interventions aimed at
changing a person’s experience of pain by
changing their thought processes
Education and Goal Setting
 Cognitive Interventions

• Cognitive Restructuring
• Cognitive Distraction
• Imagery
Life with pain…
CIPA
Diabetes
Amputations
Surgical amputation
 Traumatic amputation
 Levels of amputation
 Complications of amputations:
hemorrhage, infection, phantom limb pain,
problems associated with immobility,
neuroma, flexion contracture

Pain of the Phantom Limb

Approximately 80% of amputees have some
phantom limb sensations…





Sometimes, its a tingling sensation that they feel
Others experience pain
Intensity, duration, and severity all are variable from
patient to patient
Are they just some form of obsession neurosis
stemming from the trauma of losing one's body
part?
Or is there a biological explanation for all this?
Phantom Limb Pain




Phantom limb pain is a frequent complication of
amputation
Client complains of pain at the site of the
removed body part, most often shortly after
surgery
Pain is intense burning feeling, crushing
sensation or cramping
Some clients feel that the removed body part is
in a distorted position
Management of Pain
Phantom limb pain must be distinguished
from stump pain because they are managed
differently.
 Recognize that this pain is real and
interferes with the amputee’s activities of
daily living.

(Continued)
Management of Pain
(Continued)
Some studies have shown that opioids are
not as effective for phantom limb pain as
they are for residual limb pain.
 Other drugs include intravenous infusion
calcitonin, beta blockers, anticonvulsants,
and antispasmodics.

Exercise After Amputation
ROM to prevent flexion contractures,
particularly of the hip and knee
 Trapeze and overhead frame
 Firm mattress
 Prone position every 3 to 4 hours
 Elevation of lower-leg residual limb
controversial

Prostheses
Devices to help shape and shrink the
residual limb and help client readapt
 Wrapping of elastic bandages
 Individual fitting of the prosthesis; special
care

The Cost of Pain
• Pain inflicts significant costs on individuals, their
families, the health services and society in general.
• The economic costs are very high due to extended
hospital stays, lost working days and increased take-up
of benefits.
• The cost of pain in terms of human suffering is also
high.
• It is often the most distressing and debilitating aspect of
chronic illness.
• Its effects on quality of life can be devastating to the
individual and their significant others.
• The emotional toll of severe chronic pain should not be
underestimated
It is estimated that around
50% of severe chronic pain patients
consider suicide.
Credits




http://www.psych.yorku.ca/jirvine/3440/lectures/lecture_7_chronic_
pain/lecture_7_chronic_pain.ppt
https://courses.stu.qmul.ac.uk/smd/kb/B&B2/PAIN%20lecture%202
005.ppt
http://www.western.cc.ok.us/nursing/NURS%202229/powerpoints/
msn_pwrpoints/Chapter_055.ppt
http://www.sagepub.co.uk/marks/materials/Ch16%20slides.ppt