Chronic pain management involves comprehensive evaluation and treatment of pain. The IASP defines chronic pain as pain persisting beyond normal tissue healing time, usually 3 months. It impacts function and well-being. Treatment includes pharmacotherapy like opioids, nonopioids, and adjuvant analgesics. Opioids require careful patient selection, dosing, monitoring, and side effect management. Adjuvant analgesics like anticonvulsants and antidepressants are effective for neuropathic pain. A multimodal approach balances analgesia and side effects for optimal chronic pain treatment.

1. Chronic pain management
Dr. Ankit Gajjar

2. IASP Definition of Pain
“Pain is an unpleasant sensory
and emotional experience
associated with actual or potential tissue
damage or described in
terms of such damage.”

3. IASP Defination of chronic
pain
Pain without apparent biological value
that has persisted beyond the normal
tissue healing time usually taken to be
3 months and that affect the function or
well being of the patient

4. Chronic pain may be:
1) Non malignant
a)inflamatory
b)musculoskeletal
c)neuropathic
2) Malignant
3) chronic pain syndrome

5. Physiology of Pain Perception
 Transduction
 Transmission
 Modulation
 Perception
 Interpretation
 Behavior
Injury
Descending
Pathway
Peripheral
Nerve
Dorsal
Root
Ganglion
C-Fiber
A-beta Fiber
A-delta Fiber
Ascending
Pathways
Dorsal
Horn
Brain
Spinal Cord
5

6. Gate Control Theory
(Melzack & Wall, 1965)
A gate in the substantial gelatinosa of the dorsal horn can be open or
closed, blocking pain information.
The gate can be closed by descending signals from the brain, or by
the balance of activity in A-beta fibres (large myelinated) and C
fibres (small non-myelinated)
 A-beta fibres produce touch sensations
 C fibres produce dull diffuse pain.
Greater activity in A-beta fibres closes the gate, greater activity in C
fibres opens it.
 Other factors influencing the gate include
 Attention
 Emotional & Cognitive factors
 Physical factors
Some forms of analgesia, e.g. TENS & acupuncture, might be
accommodated within gate control theory.

7. Opening & Closing the Gate
Factor Opens Closes
Physical injury
agitation
medication
Emotional anxiety
stress
frustration
depression
tension
relaxation
optimism
happiness
Behavioural
(Cognitive)
rumination
boredom
enjoyable activities
complex tasks
distraction
social interaction

8. Domains of Chronic Pain
Social
Consequences
 Marital/family
relations
 Intimacy/sexual
activity
 Social isolation
Socioeconomic
Consequences
 Healthcare costs
 Disability
 Lost workdays
Quality of Life
Physical functioning
Ability to perform
activities of daily
living
Work
Recreation
Psychological
Morbidity
Depression
Anxiety, anger
Sleep disturbances
Loss of self-esteem

9. Evaluation of chronic pain
 Describing pain only in terms of its
intensity is like describing music only
in terms of its loudness

10. Multidimensional Classification of Pain
IASP expert multi-axial classification of chronic pain
Axis I : Regions
Axis II : Systems
Axis III : Temporal Characteristics
Axis IV : Patient’s Statement of Intensity
Axis V : Etiology
Example:
Mild postherpetic neuralgia of T5 or T 6; 6 months’ duration = 303.22e
Axis I: Thoracic region
Axis II: Nervous system (central, peripheral, or autonomic); physical
disturbance/dysfunction
Axis III: Continuous or nearly continuous, fluctuating severity
Axis IV: Mild severity of 1 to 6 months
Axis V: Trauma, operation, burns, infective, parasitic (one of these)

11. PAIN HISTORY
 Description: severity, quality, location,
temporal features, frequency, aggravating &
alleviating factors
 Previous history
 Context: social, cultural, emotional,
spiritual factors
 Meaning
 Interventions: what has been tried?

12. Pain Intensity Rating Scales
 Visual Analogue Scale (VAS)
 Numerical Rating Scale
0 -------------------------------------------
No pain
 Categorical Scale
None (0) Mild (1 – 4) Moderate (5 – 6) Severe (7 – 10)
10
Worst pain
maginable

13. Medication(s) Taken
 Dose
 Route
 Frequency
 Duration
 Efficacy
 Adverse effects

14. Physical Exam In Pain Assessment
Inspection / Observation
“You can observe a lot just by watching”
 Overall impression… the “gestalt”?
 Facial expression: Grimacing; furrowed brow; appears anxious;
flat affect
 Body position and spontaneous movement: there may be
positioning to protect painful areas, limited movement due to
pain
 Diaphoresis – can be caused by pain
 Areas of redness, swelling
 Atrophied muscles
 Gait
 Myoclonus – possibly indicating opioid-induced neurotoxicity

15. Physical Exam In Pain Assessment
Palpation
 Localized tenderness to pressure or percussion
 Fullness / mass
 Induration / warmth
 Psychological evaluation
 Goal of psychological evaluation is to determine the
contribution of affective, cognitive behavioral factors to the
perception and report of pain.
 Diagnostic imaging techniques:
Radiography
Ultrasonography
Doppler
CT scan
MRI

16. Pain in Children
 Children feel pain just as intensely
 Keeping parents informed, as part of the “team” is
important
 Anticipatory guidance helps children to cope with
pain more effectively
 Careful calculations for dosing adjustments is vital
 Dosages are usually based on child’s weight
 Children can use a faces scale for pain assessment

17. Evaluation of pain in children

18. PAIN
TREATMENT

19. Modified WHO Analgesic Ladder
Proposed 4th Step
The WHO Ladder

20. Pharmacotherapy
Analgesics
 Nonopioids
 Adjuvant Analgesics
 Opioids

21. Opioid Therapy: Drug Selection
Short-Acting Opioids
- Morphine
- Oral transmucosal fentanyl
- Tramadol
Long-Acting Opioids
- Transdermal Fentanyl
- Methadone
- Extended-release morphine
- Oxycodone

22. Opioid Therapy: Drug Selection
Advantages of Long-Acting Opioids:
- Fewer peaks and troughs
- Sustained pain relief
- Dosed less often, improved adherence
- Potentially improved patient satisfaction and quality
of life

23. Opioid Therapy:
Prescribing Principles
- Drug Selection: Elements to Consider
Severity of pain, previous exposure, availability,
patient’s preference, renal/liver function, cost
- Dose to Optimize Effects
Fixed schedule (or around-the-clock) vs as- needed
dosing; rescue doses
- Treat Side Effects
Goal: balance between analgesia and side effects
- Manage the Poorly Responsive Patient
Consider a variety of alternative strategies

24. Opioid Therapy: Dosing
- By-the-clock (fixed-schedule) dosing with long-
acting opioid plus an “as-needed” short-acting
“rescue” opioid (usually 5%–15% of total daily
dose, q 2-3 h prn)
- Baseline dose increases: 25%–100% or
equal to “rescue” dose use
- Increase “rescue” dose as baseline dose increases

25. Opioid Therapy:
Route of Administration
- Oral / Transdermal
- Rectal
- Parenteral (IV, SC)
- Intraspinal (epidural, intrathecal)

26. Opioid Titration
- Dose titration over time is key to successful opioid
therapy
- There is no ceiling dose for pure-agonist opioids.
Titrate dose upward for maximum pain relief with
acceptable side effects
- Consider rescue medication for breakthrough pain
- Responsiveness of an each patient to each drug
varies
- If a patient does not respond well on one opioid, it
is important to try another (opioid rotation)

27. Opioid Therapy: Patient Selection
-Thorough Evaluation
_pain history
_physical exam
coexisting conditions
- Review of Previous Medical/Pain History
_any psychological disturbances
_chronic pain history
- Substance Abuse History (including alcohol)
_remote, recent or ongoing
_patient goals/expectations
consistent with physician’s?
feasible/reasonable?

28. Opioid Therapy:
Monitoring Outcomes
Monitoring the 4 A’s
1.Analgesia (pain relief)
2.Activities of Daily Living (psychosocial
functioning)
3.Adverse Effects (side effects)
4.Aberrant Drug-Taking (addiction-related
outcomes)

29. Opioid Therapy: Managing the
Poorly Responsive Patient
If dose escalation increases adverse effects
- Side-effect management
- Pharmacologic strategy to lower opioid
requirement
_spinal route of administration
_add nonopioid or adjuvant analgesic
- “Opioid rotation”
_nonpharmacologic strategy to lower opioid
requirement

30. Opioid Therapy: Managing the
Poorly Responsive Patient
Opioid Rotation
- Based on large intra-individual variation in
response to different opioids
- Reduce equianalgesic dose by 25%–50% with
provisos:
_reduce less if pain severe
_reduce more if medically frail
_reduce less if same drug by different route
_reduce transdermal fentanyl less (no cutback from
equianalgesic dose)
reduce methadone more: 75%–90%

31. Opioid Therapy:
Managing Side Effects
Common
Constipation
Somnolence, mental clouding
Less Common
- Nausea - Sweating
- Myoclonus - Amenorrhea
- Itch - Sexual dysfunction
- Urinary retention - Headache

32. Opioid-Induced Neurotoxicity(OIN)
 Neuropsychiatric syndrome
 Cognitive dysfunction
 Delirium
 Hallucinations
 Myoclonus/seizures
 Hyperalgesia/allodynia

33. OIN: Treatment
 Opioid rotation
 Reduce opioid dose
 Hydration
 Circadian modulation
 Psychostimulants

34. Tolerance
 Reduced potency of analgesic effects of
opioids following repeated administration,
i.e., increasing doses are necessary to
produce pain relief
 Related to opioid receptor regulation
 Less common in pts with cancer pain
 Often reason pts “save” opioids until
terminal phase

35. Dependence
 Physical dependence: normal response to
chronic opioid administration
 Evident with opioid withdrawal: yawning,
sweating, tremor, fever, increasesd HR,
insomnia, muscle/abdominal cramps,
dilated pupils
 Avoided by decreased dose 20-30%/day

36. Addiction
- Psychological dependence
- “A pattern of drug use characterized by a
...craving for opioids...manifest...[by]
compulsive drug-seeking behavior leading
to...overwhelming involvement in use and
procurement of the drugs.”

37. PSEUDO-ADDICTION:
 Physical dependence confused with
psychological 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

38. Nonopioid Analgesics:
Acetaminophen
- Minimal anti-inflammatory effect
- Fewer adverse effects than other nonopioid
analgesics
- Adverse effects:
_renal toxicity
_risk of hepatotoxicity at high doses;
_increased risk with liver disease or chronic
alcoholism
- No effect on platelet function

39. Nonopioid Analgesics:
NSAIDS
Mechanisam of action: Action
- Inhibit both peripheral and central cyclo-
oxygenase, reducing prostaglandin formation
- 2 isoforms of COX
_COX-1: Constitutive, physiologic
_COX-2: Inducible, inflammatory

40. Nonopioid Analgesics:
NSAIDS
- Major recent advance: COX-2 selective NSAIDS
- COX-2 selective inhibitors have better GI safety
profile; no change in platelet function
- Drug selection should be influenced by drug-
selective toxicities, prior experience, convenience,
cost
- Great individual variation in response to different
drugs
- Use with caution in patients with renal
insufficiency, congestive heart failure or volume
overload

41. Adjuvant Analgesics
CLASS EXAMPLES
Anticonvulsants gabapentin, valproate, phenytoin,
carbamazepine, clonazepam,
topiramate, lamotrigine
Antidepressants amitriptyline, desipramine, nortrip-
tyline, paroxetine, citalopram, others
Local Anesthetics mexiletine
Corticosteroids dexamethasone, prednisone
α-2 Adrenergic Agonists tizanidine
NMDA-Receptor Agonists dextromethorphan, ketamine
Topicals lidocaine, lidocaine/prilocaine, capsaicin
Miscellaneous baclofen, calcitonin
Adjuvant Analgesics for Neuropathic Pain

42. Adjuvant Analgesics:
Anticonvulsants
Common Characteristics
- Most clinical experience: gabapentin, carbamazepine, phenytoin,
valproate, clonazepam
- Limited data on efficacy of newer anticonvulsants
- Used as an analgesic, dosing schedule is similar to anticonvulsant
indication
- Large inter-/intra-individual variability in analgesic response
Gabapentin
- Usual first-line drug for neuropathic pain
- Favorable safety profile
- Positive controlled trials in PHN/diabetic neuropathy
- No controlled studies in cancer patients
- Usual starting dose 100-300 mg/day
- Titration to identify responders/nonresponders
- Usual effective dose 600-3600 mg/day; higher doses sometimes
beneficial

43. Pregabalin
 Very similar to gabapentin
 More reliable oral absorption
 Slightly different side effect profile
 Doses: 75-300mg BD

44. Adjuvant Analgesics:
Antidepressants
- Evidence is best for tricyclics
- SSRI/atypical antidepressants better tolerated
- Proven efficacy for all types of neuropathic pain,
but often preferred for continuous dysesthesias
- Analgesic doses for tricyclics is usually less than
the antidepressant dose

45. Antidepressants in
Neuropathic Pain Disorders*
 Multiple mechanisms of action
 Randomized controlled trials and meta-analyses
demonstrate benefit of tricyclic antidepressants
(especially amitriptyline, nortriptyline, desipramine)
for postherpetic neuralgia and diabetic neuropathy
 Onset of analgesia variable
 analgesic effects independent of antidepressant
activity
 Improvements in insomnia, anxiety, depression
 Desipramine and nortriptyline have fewer adverse effects

46. Tricyclic Antidepressants
 Action: Mixed ( 5-HT &/ Norad at synapse)
 Indication:
 All NP treatment (except SCI, PLP, HIV)
 NNT: overall = 3.1, central = 4.0, periph =
2.3
 PHN prevention: 50%  if used for 90days
 SE: dizzy, sedation, anticholinergic
 NNH minor = 5, NNH major = 16
 Doses
 Amitriptylline 10-25mg nocte, max 100mg
 Nortriptylline (?less sedating) same doses

47. Adjuvant Analgesics:
Corticosteroids
- Shown to improve pain, appetite, nausea,
malaise, quality of life in cancer patients
- In the cancer population, indicated for
refractory neuropathic pain, and other
indications: bone pain, bowel obstruction,
capsular pain, lymphedema, headache
- In non-cancer pain, long-term use is limited to
inflammatory conditions
- Usual drugs are prednisone and dexamethasone

48. Adjuvant Analgesics:
α-2 Adrenergic Agonists
- Evidence of nonspecific analgesic effects
- Established analgesic effect of epidural
clonidine in neuropathic cancer pain
- Tizanidine usually better tolerated (starting
dose 1-2 mg/day; usual maximum dose up to 40
mg/day)

49. Adjuvant Analgesics:
NMDA-Receptor Antagonists
- N-methyl-D-aspartate receptor involved in neuropathic
pain
- Commercially-available drugs in the U.S.: ketamine,
dextromethorphan, amantadine
_Ketamine: dissociative anesthetic; can be used p.o. or
IV/SC infusion
_Dextromethorphan: antitussive; starting dose 120
mg/day; maximum daily dosage one gram
_Amantadine: starting does 100 mg b.i.d.

50. Topical analgesics
 1) NSAIDS
 2) LA
 3) Capsaicin
Other adjuvants
1)anti emetics
2)laxatives

51. Topical vs Transdermal
Drug Delivery Systems
Systemic activity
Applied away from painful site
Serum levels necessary
Systemic side effects
Peripheral tissue activity
Applied directly over painful site
Insignificant serum levels
Systemic side effects unlikely
Topical
(lidocaine patch 5%)
Transdermal
(fentanyl patch)

52. Lidocaine Patch 5%
 Lidocaine 5% in pliable patch
 Up to 3 patches applied once daily directly over
painful site
 12 h on, 12 h off (FDA-approved label)
 recently published data indicate 4 patches (18–24 h) safe
 Efficacy demonstrated in 3 randomized controlled trials on
postherpetic neuralgia
 Drug interactions and systemic side effects unlikely
 most common side effect: application-site sensitivity
 Clinically insignificant serum lidocaine levels
 Mechanical barrier decreases allodynia

53. Calcitonin
 Action: uncertain
 Indication: PLP, CRPS, ?other NP
 SE: N/V, flushing, dizzy, allergy
 Skin prick test advised
 Dose: 100 IU in 100ml saline over 1hr
 Pre-treat with anti-emetics
 Repeat daily for 3 days

54. “In deciding whether opioids are
indicated…, it is more appropriate to
determine whether opioids reduce pain,
improve function in valued life roles,
and result in overall enhancement of
well-being, without posing unacceptable
risks or side effects, than to make the
decision based solely on a diagnosis.”

55. Non-Pharmacological Pain
Management
1. Anaesthesiological therapies
A) nerve blocks
a) diagnostic
b) therapeutic
B) continuous catheter technique
a) epidural
b) intrathecal

56. Interruption of Pain Signal and
Anesthetic Intervention
- Neuro-Axial Drug Delivery System
- Neural Blockade

57. Neuro-Axial Drug Delivery System
- Indication:
- Route:1-Epidural
2-Intrathecal (external vs internal pump)
3-Regional Plexus Catheter

58. Neurostimulatory therapies
A) Spinal cord stimulation (SCS)
B) Transcutaneous electrical nerve
stimulation (TENS)

59. Surgical therapies
- Rarely use as a primary treatment such as in
neuroma Because of availibility of new therapy
and risk of surgical complication, surgery is
rarely use nowdays….
- Radiation therapy
- Chemotherapy
- behavioral changes

60. Neurolytic procedures
- Celiac plexus
- Superior hypogastric plexus
- Ganglion impar
- Posterior root

61. Spinal Cord Stimulation
- Spinal cord stimulation (SCS) is a safe and effective therapy
_in use for over 35 years
_has helped thousands of people find pain relief
- Implantable Pulse Generator is implanted under the skin
_Leads are then placed under the skin next to the spinal cord
_Signals sent to spinal cord create paresthesia, masking the pain
- Reversible procedure – surgically implanted device can be
removed
- When is SCS appropriate?
_For severe and long-lasting neuropathic pain
_When other treatments are not working well

62. Precision™ is the first
long-lasting, rechargeable
Spinal Cord Stimulation
(SCS) system.
Small - half the size of
other SCS systems
Only system with
independent current control
allows clinician to better
control pain coverage
Can cover multiple pain
areas simultaneously
Maintains therapeutic
stimulation patterns
regardless of impedance
changes (scar tissue)

63. Preparing the Patient for Test
Stimulation
- Position and
sedate the
patient
- Mark interspinous
intervals with
fluoroscopy
- Mark desired
entry level

64. Percutaneous Lead Placement
- Insert Touhy needle
- Confirm needle
location with
fluoroscopy and
loss of resistance
- Introduce guidewire
- Insert lead
Confirm lead location
with fluoroscopy

65. Dual Lead Placement
- Insert second
needle one level
below/contralateral
to first
- Place lead tips at
same level or
staggered

66. Intraoperative Screening
- Connect lead and
screener
- Goal of matching
stimulation to pain
pattern
- Test by trying
different electrode
combinations and
polarities

67. Test Stimulation:
Partial Percutaneous Lead Implant
- Least invasive
initial approach
- Preferred test
stimulation
for surgical leads
- Lead secured to skin
- Allows for test
stimulation
of several days

68. Optimizing SCS Therapy
- Patients can test SCS Therapy prior to
permanent implantation
- Trial SCS
- Incision is made to place a lead in
the epidural space near the spinal cord
- External trial stimulator is connected,
producing the paresthesia
- Patient is awake while a computer to
guides the pain-masking signals to
provide optimal pain relief
- Patient wears the remote-controllable
system on a belt for 5-14 days

69. Optimizing SCS Therapy (cont)
- Implanting a permanent
device
If the SCS Trial goes well,
the permanent SCS device
will be implanted
- Programming the
SCS
Doctor steers the signal as
patient says where it feels best
For people with complex pain,
or pain in multiple locations,
the Precision system offers
the ability to deliver pain-masking
signals to up to four locations
at the same time

70. Psychological therapy
- Also called MIND BODY THERAPIES
- Psychological factors are important contributor to
the intensity of chronic pain and disability associated
with chronic pain..
- There may be a vicious cycle between pain and
stress…
- Some indications:
- relavant somatisation
- depressive disorder
- drug abuse
- inadequate coping

71. Familial Involvement and
Functioning
- Supportive
- Over solicitous
- Impact on family
functioning and roles
- Entrenched family models

72. Physical Therapy
- Passive modalities used in
moderation
- Functional outcomes emphasized
over pain reduction
- Goal should be to make the
patient independent in a
maintenance exercise program

73. Other ways to
control Pain
- Acupuncture
- Distraction
- Meditation
- Massage
- Hypnosis

74. Can we offer this ?