1. Dr.P.NARASIMHA REDDY M.D D.A
Professor And H.O.D
Dept.Of Anesthesiology
Narayana medical college hospital
Nellore.

2. Good Evening

3. 
Pain is defined by international association for
study of pain as “An unpleasant sensory and
emotional experience associated with actual or
potential tissue damage or described in terms
of such damage”.

4. 



Pain is always a subjective experience
Everyone learns the meaning of “pain” through
experiences usually related to injuries in early life
As an unpleasant sensation it becomes an
emotional experience
Pain is a significant stress physically, emotionally

5. Somatic pain:caused by the activation of pain receptors in either
the cutaneous (the body surface) or deeper tissues (musculoskeletal
tissues).
Visceral pain: pain that is caused by activation of pain receptors
from infiltration, compression, extension or stretching of the thoracic,
abdominal or pelvic viscera (chest, stomach and pelvic areas).
Neuropathic pain: caused by injury to the nervous system either
as a result of a tumor compressing nerves or the spinal cord, or
cancer actually infiltrating into the nerves or spinal cord.

6. 


Mild: ??
Moderate: ??
Severe: ??

Although descriptive, does not provide correct
information, perhaps these should be used to modify
acute and chronic pain indications to allow patients to
understand, but how do you measure what is mild,
moderate, severe: ultimately it is the bias of the agency,
investigators, sponsors to suggest which is which.

7. 
Acute pain: short-lasting and manifesting in objective ways
that can be easily described and observed. It may be clinically
associated with diaphoresis and tachycardia. It can last for
several days, increasing in intensity over time (subacute pain),
or it can occur intermittently (episodic or intermittent pain).
Usually related to a discreet event for onset: post op, post
truama, fracture, etc

Chronic pain: Long-term and typically defined if it lasts for >
three months. It is more subjective and not as easily clinically
characterized as acute pain and is more psychological. This
kind of pain usually affects a person's life, changing personality,
their ability to function, and their overall lifestyle.

8. Chronic pain has a psycho-social component that
must be dealt with before depression becomes a part
of the clinical picture. Chronic pain should be
recognized as a multi-factorial disease state requiring
intervention at many levels.

11. 1.
2.
Normal or Nociceptive pain – includes
acute,subacute & inflammatory pain.
Abnormal or pathophysiologic pain –
Neuropathic and central pain.

12. 

-
Nociceptors : are free nerve endings,
innervated by A-delta and C nerve fibers, that
respond to intense ,potentially damaging
stimuli that exist throughout the body.
Found in skin in form of
High threshold mechanoreceptors
Polymodal receptors
Silent receptors.

13. 
Chemical mediators:

14. 
Local release of prostaglandins potentiate the
action of bradykinin and acts as sensitiser to
nociceptors.

17. 

First order neurons:Nociceptive afferent fibers
terminate in spinal dorsal horn on the same
side as the dorsal root ganglion where primary
sensory neural cells are located.
Rexed laminae:

19. Second order neurons:
1. Wide dynamic range neurons.(WDR)
2. Nociceptive specific neurons.
 WDR neurons are located in laminae V of
dorsal horn.


20. 


Occurs at Nociceptor, spinal cord or in supra
spinal structures.
It can either facilitate or inhibit pain.
At the spinal level modulation is via “GATE
CONTROL THEORY” by MELZACK & WALL.

21. 


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.

23. 
Physical conditions



Emotional conditions




Extent of injury
Inappropriate activity level
Anxiety or worry
Tension
Depression
Mental Conditions


Focusing on pain
Boredom

24. 
Physical conditions



Emotional conditions



Medications
Counter stimulation (e.g., heat, message)
Positive emotions
Relaxation, Rest
Mental conditions


Intense concentration or distraction
Involvement and interest in life activities

25. 

A-delta fibers – small, myelinated fibers that
transmit sharp pain
C-fibers – small unmyelinated nerve fibers that
transmit dull or aching pain.

26. 

Hypothalamus, pons and somatosensory cortex
: stimulation of these areas causes analgesia
Three endogenous systems involved in the
inhibitory pathways for pain: (1) the opioid
system, (2) the noradrenergic system, and (3)
the serotonergic system

27. 
Increased catabolic demands: poor wound
healing, weakness, muscle breakdown.

Decreased limb movement: increased risk of
DVT/PE
Respiratory effects: shallow breathing, tachypnea,
cough suppression increasing risk of pneumonia
and atelectasis.


Increased sodium and water retention (renal)
Decreased gastrointestinal mobility.

Tachycardia and elevated blood pressure


28. 


Negative emotions: anxiety, depression
Sleep deprivation
Existential suffering: may lead to patients
seeking active end of life.

29. 

Decrease natural killer cell counts
Effects on other lymphocytes not yet defined.

31. 


Chronic pain is pain that:
 continues a month or more
beyond the usual recovery
period for an injury or illness or
 goes on for months or years
due to a chronic condition.
The pain may not be constant but
disrupts daily life.
It also can interfere with sleep,
keeping you awake a night.

32. Loneliness
Hostility
Social Factors
TIME
Anxiety
Depression
Psychological Factors
Pathological
Process
Physical Factors

33. 


Nociceptive,Neuropathic or both.
Psychological mechanisms play a major role.
Attenuated neuroendocrine stress response
and have prominent sleep and affective
disturbances.

34. 


Neuropathic pain: Paroxysmal and
lancinating,has a burning quality and is
associated with hyperpathia.
Deafferentation pain: neuropathic pain
associated with loss of sensory input into the
CNS.
Sympathetically mediated pain:sympathetic
system plays a major role.

35. 




Psychologic factors – depression, anxiety, somatization
Socioeconomic factors – cultural differences, urban
poor, gender
Spiritual factors – spiritual suffering, meaning of pain
Physical factors – VERY complex neuroanatomy creating
the pain sensation, from pain receptors to afferent
nerves to spinothalamic tract, to thalamus to cortex with
modulators all along the way
Therefore best approach is multi-disciplinary

36. Episodic pain syndromes:
 Headaches – migraine, tension, cluster…
 Ischemic episodes – claudication, angina, sickle
cell disease
 Visceral pain – biliary colic, irritable bowel, premenstrual syndrome, renal colic
 Somatic pain - gout

37. Chronic pain syndromes:
 Somatic – low back pain ,degenerative and inflammatory
arthitis, lumbosacral radiculopathy,Failed back surgery,
vertebral compression fractures, bony metastases,
Myofascial pain syndrome.

Visceral – abdominal cancers, chronic pancreatitis.

Neuropathic – CRPS,Post herpetic neuralgia,Trigeminal
neuralgia,diabetic neuropathy, phantom limb pain, spinal
stenosis/sciatica, spinal mets,

38. 


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.

39. 


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
MEDICAL EVALUATION:
Location,onset.
Quality,radiation.
Response to previous treatments.
h/o
past,personal,social,economic,psychological
and emotional status.
Plain radiographs,CT,MRI, bone scans.

40. PSYCHOLOGICAL EVALUATION:
1. Clinical interview.
2. A structured pain inventory
a. Mc Gill pain questionnaire.
b. Psychosocial pain inventory.
c. Westhaven - Yale multidimensional pain
inventory.
d. Pain profile.


41. 3. Psychometric testing:
a. Minnesota multiphasic pain inventory(MMPI)
b. Symptom check list-90.
c. Million behavioural pain inventory.
d. The beck depression inventory.
e. The spielberger state-trait anxiety scale.

42. 


Electromyography and Nerve conduction
studies:
Useful for confirming diagnosis of entrapment
syndromes,neural trauma and
polyneuropathies,radicular syndromes.
Can distinguish b/n neurogenic and myogenic
disorders.

43. 

-
Reliable quantitation of pain severity helps
determine therapeutic interventions and
evaluate the efficacy of treatments.
PAIN SCALES:
Numerical rating scale.
Faces rating scale
Visual analog scale.
McGill pain questionnaire.

44. VISUAL ANALOGUE
SCALE

45. McGill Pain questionnaire:
 It is a checklist of words describing symptoms.
 Attempts to define the pain in 3 major
dimensions.
1. Sensory – discriminative.
2. Motivational – affective.
3. Cognitive – evaluative.


46. Contains 20 sets of words that are divided into
4 groups.
1. 10 sensory.
2. 5 affective.
3. 1 evaluative.
4. 4 miscellaneous.


47. 
Low back pain:

48. 



Treatment:
Bed rest widely recommended but shown to
impede recovery.
Current consensus – maintenance of activity
and work status.
If beyond 4-wks – refer to multidisciplinary pain
centre.

49. 



General term for congenital and acquired
disorders of spine.
Narrowing of the bony frame surrounding the
neural structures .
Can affect central spinal canal or lateral
intervertebral foramen.
Narrowing can be caused by
spondylolisthesis,osteoarthritis of
spine,degenerative disk disease.

50. 




Also called as post laminectomy syndrome.
One of the most difficult groups of chronic pain
patients.
Exhibits strong nociceptive and neuropathic
characteristics.
Pain may be sharp and shooting
,burning,dydesthic.
Iatrogenic and due to development of fibrous
scarring.

51. 




Soft tissue disorder that creates pain in tender
areas within muscle groups.
Diagnosis made on clinical trigger points .
Trigger points are painful regions in a taut band of
muscle that produces referenced pain with
application of pressure.
Painful area usually feels like a “rope”.
Created by events like trauma or prolonged
tension from poor posture.

52. 

Local prolonged ischemia may trigger the
formation of subsequent fibrosis.
Therapeutic modalities – passive
stretching,cold spray,compression
massage,injection of 0.5% lidocaine at the
trigger point,botulinum toxin injection.

53. 
Common complaint.

54. 



Neuropathic pain that involves upper and lower
extremities.
Reflex sympathetic dystrophy and causalgia are
replaced by CRPS I ,CRPS II.
CRPS type I: follows minor trauma.
Preceeding events are
trauma,surgery,sprain,fracture,dislocation.

55. 
3 phases.

56. 



CRPS type II: also called as causalgia.
Burning pain,follows high velocity injuries to
large nerves.
Pain immediate in onset.
Associated with
allodynia,hyperpathia,vasomotor and
sudomotor dysfunction.

57. 



Treatment:
Sympathetic blocks.
Physical therapy plays major role.
Cure rate is high if Rx initiated within 1month of
symptoms and appears to decrease with time.

58. 


Intractable pain that develops as a sequel of
acute herpes zoster infection.(AHZ)
Pain from AHZ resolves usually within 3-4
weeks and if pain lasts longer than 4-6wks
PHN should be suspected.
In AHZ large myelinated fibers are destroyed
whereas in PHN pain processing by small fibers
is compromised.

59. 




Typically presents with unilateral pain in
dermatomal distribution.
Treatment:
Sympathetic blockade during attack
Antidepressants,anticonvulsants,opioids.
TENS.

60. 


TIC DOULOUREUX
classically presents as a painful, unilateral affliction
of the face, characterized by brief electric-shock-like
pain, limited to the distribution of one or more
divisions of the trigeminal nerve.
Pain is commonly evoked by trivial stimuli, including
washing, shaving, smoking, talking and brushing the
teeth, but may also occur spontaneously. The pain
is abrupt in onset and termination may remit for
varying periods.

61. 



Treatment:
Carbamazepine.
Invasive treatment- Glycerol
injection,Radiofrequency ablation of gasserian
ganglion
Microsurgical decompression of trigeminal
nerve.

63. 



Improvements in nociception, not
curing.
Decrease pain and suffering
Increase daily activity.
Instill hope

64. 1.
2.
3.
4.
PHARMACOLOGICAL.
PHYSICAL MEASURES/NON
PHARMACOLOGICAL.
PSYCHOLOGICAL MEASURES.
INVASIVE TECHNIQUES.

65. 


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

66. 


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
NSAIDS, COX INHIBITORS.
OPIOIDS
ANTI DEPRESSANTS
ANTI CONVULSANTS
CORTICOSTEROIDS
LOCAL ANAESTHETICS – systemic
administration.

67. 

Traditional NSAIDs are effective in the treatment
of mild to moderate pain, but their use is limited
by potentially serious adverse effects
ketorolac : indicated only in the management of
moderately severe acute pain that requires opioid
level analgesics ; no more than 5 days

68. 

COX-2 selective inhibitors [celecoxib
(Celebrex), rofecoxib (Vioxx) and valdecoxib
(Bextra)]
200-fold to 300-fold selectivity for inhibition of
COX-2 over COX-1

69. 



Codeine
Fentanyl
Hydrocodone
Hydormorphone
Methadone
Morphine
Oxycodone
Oxymorphone

70. 




Individualize route, dosage, and schedule
Administer analgesics regularly (not PRN) if
pain is present most of day
Become familiar with dose / time course of
several strong opioids
Give infants / children adequate opioid dose
Follow patients closely, particularly when
beginning or changing analgesic regimens

71. 
When changing to a new opioid or different route


Use equianalgesic dosing table to estimate new dose
Modify estimate based on clinical situation

Recognize and treat side effects

Be aware of potential hazards of meperidine / mixed
agonist-antagonists - particularly pentazocine

Do not use placebos to assess nature of pain

72. 
Watch for development of:


Tolerance - treat appropriately
Physical dependence – prevent withdrawal

Do not label a patient psychologically dependent,
“addicted”, if you mean physically dependent on /
tolerant to opioids

Be alert to psychological side of patient .

73. 





Constipation , no tolerance develops to constipation,
use stimulants (Senokot, Bisocodyl, Pericolace)
Nausea/vomiting – tolerance can occur in 2-5 days.
Sedation – tolerance can occur in 2-3 days.
Clonic jerks – usually high doses, can change drug or
diazepam can help
Respiratory suppression in toxic doses, never see it if
have pain or use the drugs the right way.
Can produce Hyperalgesia in certain individuals.

74. PHYSICAL DEPENDENCE:
 Tolerance (20-40%) – up-regulate opioid receptors to need higher
dose for sustained effect
 Withdrawal (20-40%) – after 2 wks, withdrawing drug leads to
adrenaline response (sweating, tachycardia, tachypnea, cramps,
diarrhea, hypertension); avoid by decreasing drug 25% a day.
PSYCHOLOGIC DEPENDENCE:
 Addiction (0.1% in CA pain) – a need to get “high” where drug
controls your life, compulsive uncontrolled behavior to get the
drug; lie, cheat, steal.

75. PSEUDO-ADDICTION:
 Physical dependence confused with
psychologic dependence
 Pain-relief seeking, not drug-seeking
 When right dose used, patient functions
better in life, whereas opposite true with
the true addict
 To help diffentiate: one MD controls the
drug under a specific contract with pt., one
pharmacy, frequent visits, pill counts

76. 
Definition

Agents which enhance analgesic efficacy, have
independent analgesic activity for specific types of
pain, and / or relieve concurrent symptoms which
exacerbate pain

77. 




Antidepressants
Anticonvulsants
Corticosteroids
Neuroleptics
Antihistamines





Analeptics
Benzodiazepines
Antispasmodics
Muscle relaxants
Systemic local
anesthetics

78. 



Antidepressants are effective agents in the treatment
of neuropathic pain.
Action due to blockade of presynaptic reuptake of
serotonin,norepinephrine or both.
serious side effects , include anticholinergic effects
including dry mouth, confusion, and urinary
retention .
Ex.
Amitr yptiline,Clomipramine,Doxepine,Fluox
etine,Imipramine.

79. 



Antiepileptic drugs have been used for many
years in the treatment of neuropathic pain
particularly trigeminal neuralgia and diabetic
neuropathy.
Blocks voltage gated sodium channels and can
suppress spontaneous neuronal discharges.
phenytoin, carbamazepine, and valproic acid
The newer agents, gabapentin appears to be the
most effective and well tolerated

80. 


Useful in patients with marked agitation or
psychotic symptoms.
Fluphenazine,Haloperidol,Chlorpromazine and
perphenazine are commonly used.
Action due to blockade of dopaminergic
receptors.

81. 

Glucocorticoids are extensively used in pain
management for their anti inflammatory and
possibly analgesic actions.
Can be given topically,orally,parenterally.

82. 
Lidocaine Infusion


More effective in neuropathic pain but can be used for
all pain syndromes. Starting dose 0.5mg-2 mg/kg per hr
IV or SC. Some studies demonstrate long-lasting pain
relief even after drug has been stopped. Need to
decrease opioids when starting.
Lidocaine Patch (Lidoderm®)


On 12hrs off 12 hours (but can leave on 24)
Expensive (great indigent program however)

83. 


Alpha adrenergic agonist.
Action – activation of descending inhibitory
pathways.
Can be given
epidurally,intrathecally,parenterally.

84. 




N-methyl-D-aspartate receptor antagonist
(NMDA)
Used as an anesthetic for years
Case reports show effectiveness when
traditional and invasive techniques fail
Starting IV dose 150mg qd (0.1-0.2mg/kg) with
reduction of opioid achieved or 10-15 mg q6
increasing by 10 mg dose each day
Appears to have a synergistic effect with opioids

85. 





Pamidronate (Aredia)
Zoledronic acid (Zometa)
Strontium-89 (Metastron)
Calcitonin (Calcimar) Not in cancer ? arthritis
Capsaicin (Zostrix) scheduled in neuropathic pain
Cannabinoid (Marinol)

87. Quality of Life
Invasive treatments
Proposed 4 th
Step
Opioid Delivery
Pain persisting or increasing
Step 3
Opioid for moderate to severe pain
± Nonopioid ± Adjuvant
Pain persisting or increasing
The WHO
Ladder
Step 2
Opioid for mild to moderate pain
± Nonopioid ± Adjuvant
Pain persisting or increasing
Step 1
± Nonopioid
± Adjuvant
Pain

88. 

-
-
Exercises :Graded exercise program prevents
joint stiffness,muscle atrophy and contractures.
Superficial heating modalities:
Conductive – hot packs,paraffin baths,fluido
therapy.
Convective
Radiant.

89. 
ULTRASOUND: for deep pain.

90. 


ACCUPUNCTURE:
Useful adjunct for patients with chronic
musculoskeletal disorders and headaches.
Technique – insertion of needles in discrete
anatomically defined points called
“MERIDIANS”.

91. 

Used widely in chronic pain
All available trials used TENS as an adjuvant to
medication, and it’s possible the effects of
TENS was masked by the analgesic effect of
medication

92. 






Ice packs
Chiropractic/osteopathic
manipulations
Massage
Yoga
Topical agents (Ben Gay/Icy
Hot – with menthol, salcylates,
Capcaicin)
Local injections (steroids,
lidocaine)
Glucosamine shown to help
with osteoarthritis

93. 




Herbals/supplements – glucosamine shown to be useful in
osteoarthritis, certain herbs like chamomile useful for colicky pain
Homeopathies/flower essences – for relaxation, visceral pain
Healing touch/Reiki – using energy techniques, useful with
emotional components
Neuro Emotional Technique – A chiropractic technique also
useful with emotional components
Mind – focusing therapies:
•
•
•
Meditation, yoga, guided-imagery, hypnosis, biofeedback
Art/music/humor therapy, pet therapy
By distraction, found to lower HR/RR and decrease pain up to 10-20%

94. Integral part of multidisciplinary approach to
pain management.
1. Self management techniques – cognitive
methods,relaxation,biofeedback.
2. Operant techniques.
3. Group therapy.


95. 



Cognitive methods:
Based on assumptions that a patients attitude
towards pain can influence the perception of
pain.
Maladaptive attitudes contribute to suffering
and disability.
Patient is taught skills for coping with pain
either individually or in group therapy.

96. 


Biofeedback – provides biophysiological
feedback to patient about some bodily
process the patient is unaware of (e.g.,
forehead muscle tension).
Relaxation – systematic relaxation of the
large muscle groups.
Hypnosis – relaxation + suggestion +
distraction + altering the meaning of pain.

97. 


OPERANT / BEHAVIOUR THERAPY:
Based on premise that behaviour in patients
with chronic pain is determined by
consequences of behaviour.
Positive reinforcers aggravate the pain,negative
reinforcers reduce pain behaviour.

99. 

Intractable pain*
Intractable side effects*
*Symptoms that persists despite carefully
individualized patient management

100. 


SELECTION OF BLOCK:
Depends on
Location of pain
Its presumed mechanism
Skills of treating physician.
L.A ‘s can be applied locally,at peripheral
nerve,somatic plexus,sympathetic ganglia or
nerve root, centrally in neuraxis.

101. 
-
Somatic nerve blocks:
Trigeminal nerve blocks
Cervical,thoracic,lumbar paravertebral blocks
Facet blocks
Trans sacral nerve blocks etc.

103. 
-
Sympathetic blocks:
Stellate ganlion block
Celiac plexus block
Thoracic,lumbar sympathetic chain block etc.

104. CELIAC PLEXUS
BLOCK

105. EPIDURAL INJECTIONS:
- Lumbar interlaminar epidural injections
- Fluoroscopic injections
- Transforaminal injections
- Radiofrequency rhizotomy

107. 

SPINAL INJECTIONS:
Therapeutic effects of spinal injections are a
combination of primary physiologic changes
that result from the procedure and the
secondary results arising from the enhanced
pain control that allow other treatments.

108. 


Also called dorsal coloumn stimulation.
Produces analgesia by directly stimulating large
A beta fibers in dorsal coloumns of the spinal
cord.
Mechanism – activation of descending
modulating systems and inhibition of
sympathetic outflow.

109. 


Indications:
Sympathetically mediated pain
Spinal cord lesions
Phantom limb pain
Failed back surgery syndrome.
Technique: electrodes placed epidurally and
connected to an external generator.
Complications: infection,lead migration,lead
breakage.

110. 
-
-
Deep brain stimulation may be used for
intractable cancer pain and rarely for
intractable neuropathic pain of nonmalignant
origin.
Electrodes are implanted stereotactically into
periaqueductal and periventricular gray areas
for nociceptive pain.
Complications: intracranial hemorrhage and
infection.

111. 





Pain is unnecessary.
Effective tools are available to help doctors evaluate pain in
their patients. Unrelieved pain should be treated just like any
other vital sign: with aggressive measures.
Effective therapies are available to treat pain. Use guidelines
to develop a rational plan to relieve pain.
Side effects are manageable. Anticipate side effects and treat
aggressively.
Addiction rarely occurs. Trust your patient when they report
pain. Tolerance and physical dependence can occur.
Plan and you will succeed. Take the initiative and focus on
relieving pain at your hospital. Your patients depend on it.

112. 




John C.Rowlingson – Chronic Pain.Miller’s
Anaesthesia.
Raj PP:Practical Management Of Pain .
Wall PD,Melzack OC:Text book of pain.
ISA Journal On pain.
Gowri devi M;Chronic pain ManagementPsychological aspectsin current conceptsin
pain management.CMEabstract 1998.