CHRONIC PAIN

MANAGEMENT
Dr. Sami Ur Rehman
House Officer
BAAHAWAL VICTORIA HOSPITAL, BAHAWALPUR
ANAESTHESIA DEPARTMENT
 Definition of Pain
• 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”.
 VARIOUS DESCRIPTORS OF PAIN
• 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.
 cont…
• 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 trauma,
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.
 Cont…
• 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.
 WHAT IS CHRONIC PAIN?
□ 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.
• Nociceptive, Neuropathic or both.
• Psychological mechanisms play a major role.
• Attenuated neuroendocrine stress response and have
prominent sleep and affective disturbances.
• 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.
 CHRONIC PAIN IS MULTI-FACTORIAL
• 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
 Common etiologies of chronic pain

• 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
 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,
• 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.
 Evaluation of Pain
••MEDICAL EVALUATION:
Location,onset.
••Quality,radiation.
Response
•Hx of: to previous treatments.
past,personal,social,economic,psychol
ogical and emotional status.
•Plain radiographs,CT,MRI, bone
scans.
 PSYCHOLOGICAL EVALUATION:

• Clinical interview.
• A structured pain inventory
• Mc Gill pain questionnaire.
• Psychosocial pain inventory.
• Westhaven - Yale multidimensional pain inventory.
• Pain profile.
 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

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.
 Measurement of Pain:-
• 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.
 McGill Pain questionnaire:

o It is a checklist of words describing symptoms.

o Attempts to define the pain in 3 major dimensions.
1. Sensory - discriminative.
2. Motivational - affective.
3. Cognitive - evaluative.
 cont…
• Contains 20 sets of words that are divided into 4 groups:
a. 10 sensory.
b. 5 affective.
c. 1 evaluative.
d. 4 miscellaneous.
 Common Conditions:
• Low back pain:
Causes of low back pain ;
Muscle sprain/strain
Herniated nucleus pulposus
Degenerative disk disease
Annular fissure/tear
Zvgapophysial joint arthropathy
Spinal central canal or foraminal stenosis
Osteoarthritis of the hip
Spondylolisthesis
Ankylosing spondylitis
Epidural abscess hematoma
Diskitis
Osteomyelitis
Primary or metastatic cancer   
Referred abdominal aortic aneurysm, pancreatitis. renal colic, etc.
 Treatment:

o Bed rest widely recommended but shown to impede

recovery.
o Current consensus - maintenance of activity and work
status.
o If beyond 4-wks - refer to multidisciplinary pain centre.
 SPINAL STENOSIS

• General term for congenital and acquired disorders of the

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.
 FAILED BACK SURGERY

• 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.
 MYOFASCIAL PAIN SYNDROME

• Soft tissue disorder that creates pain in tender areas within.

• 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.
 Cont…
• 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.
 Complex Regional PAIN SYNDROME
(CRPS)
• 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.
CONT…
3 phases:
 cont…
• 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.
 Treatment:

a. Sympathetic blocks.

b. Physical therapy plays major role.

c. Cure rate is high if Rx initiated within 1month of symptoms and appears to

decrease with time.
 Post-Herpetic Neuralgia
• 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.
• Typically presents with unilateral pain in dermatomal distribution.
• Treatment:

a.
Sympathetic blockade during attack.

b. Antidepressants, anticonvulsants,opioids.
C. TENS.
 TRIGEMINAL NEURALGIA (TN)

• 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.
 Treatment:
o Carbamazepine

o Invasive treatment- Glycerol injection, Radiofrequency ablation of

gasserian ganglion

o Microsurgical decompression of trigeminal nerve.

CHRONIC PAIN MANAGEMENT
CHRONIC PAIN MANAGEMENT GOALS

• Improvements in nociception, not curing.

• Decrease pain and suffering.

• Increase daily activity.
• Instill hope
 THERAPEUTIC MODALITIES

1. PHARMACOLOGICAL.

2.  PHYSICAL MEASURES/NON-PHARMACOLOGICAL.

3. PSYCHOLOGICAL MEASURES

4.   INVASIVE TECHNIQUES.
 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:

D PRN -“as needed”

D As a prescribed schedule

0 NSAIDS, COX INHIBITORS o OPIOIDS

o ANTI DEPRESSANTS o ANTI CONVULSANTS o CORTICOSTEROIDS

o LOCAL ANAESTHETICS – systemic administration.

NONSTEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS)

•Traditional
effective in NSAIDs
the treatment are
of
mild to moderate pain, but their
use is limited by potentially
serious adverse effects.
• ketorolac : indicated only in the
management
severe acute of
pain moderately
that requires
opioid
5 days.
level analgesics ; no more than
• COX-2 selective inhibitors and valdecoxib (Bextra)]
• 200-fold to 300-fold COX-2 over COX-1
DRUGS Maximum suggested daily Frequency of administration of
dose (mg) drug
Acetaminophen (paracetamol) 650 q4h
Aspirin 650 Q4h

Diclofenac 75
t.d.
Diflunisal 500 t.d.
Etodolac 400 t.d.
Ibuprofen 800 q.d.
Indomethacin 50
Ketoprophen 75 q.d.
Ketorolac3 10 q.d.
Choline magnesium trisalicylate 1500 q.d.

Nabumetone 1000 t.d.

Naproxen 500 t.d.

Piroxicam 40 t.d.
Sundac 200 q.d.
Selective COX-2 inhibitors (Celecoxib, 400, 50 b.d,,,,,,q.d
Rofecoxib)
i/v,i/m dose is 30mg q6hrly
o Codeine o Fentanyl o Hydrocodone o Hydormorphone
o Methadone o Morphine o Oxycodone o Oxymorphone

OPIOIDS
 PRINCIPLES OF OPIOID ANALGESIC USE
IN CHRONIC PAIN
• Individualize route, dosage, and schedule
o Administer analgesics regularly (not PRN) if pain is present most of day
a Become familiar with dose / time course of several strong opioids.
b. Give infants / children adequate opioid dose.
c. Follow patients closely, particularly when beginning or changing analgesic
regimens
Cont…

o When changing to a new opioid or different route

o Use equianalgesic dosing table to estimate new dose

o 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

• Watch for development of: Cont…
o Tolerance - treat appropriately

o Physical dependence - prevent withdrawal

o Do not label a patient psychologically dependent, “addicted”, if you mean physically

dependent on /tolerant to opioids
o Be alert to psychological side of patient .
 Opiods side-effects:-
>    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.
 PHYSICAL V/S PSYCHOLOGICAL
DEPENDENCE
• 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.
 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 differentiate: one MD controls the drug under a specific contract with
pt., one pharmacy, frequent visits, pill counts
 CO ANALGESICS

o Definition
• Agents which enhance analgesic efficacy, have independent analgesic
activity for specific types of pain, and / or relieve concurrent symptoms which
exacerbate pain
 CO ANALGESICS COMMONLY USED FOR PAIN
• Antidepressants  
• Anticonvulsants   
• Corticosteroids
• Neuroleptics
• Antihistamines

• Analeptics
• Benzodiazepines
• Antispasmodics
• Muscle relaxants,,
• Systemic local anesthetics
 ANTIDEPRESSANTS
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 .

• Eg. Amitryptiline, Clomipramine, Doxepme, Fluoxetine,

Imipramine.
 Anti-epileptic drugs
□ 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
 Neuroleptic Drugs
D Useful in patients with marked agitation or psychotic symptoms.

D Fluphenazine, Haloperidol, Chlorpromazine and perphenazine are

commonly used.

D Action due to blockade of dopaminergic receptors.

 CORTICOSTEROIDS:

D Glucocorticoids are extensively used in pain management for their

anti inflammatory and possibly analgesic actions.
D Can be given topically, orally, parenterally.
 LOCAL ANESTHETICS

• 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®)

o On 12hrs off 12 hours (but can leave on 24)
o Expensive (great indigent program however)
 CLONIDINE:

• Alpha adrenergic agonist.

• Action - activation of descending inhibitory pathways.
• Can be given
• epidurally, intrathecally, parenterally.
 KETAMINE
• o N-methyl-D-aspartate receptor antagonist (NMDA)
• o Used as an anesthetic for years
• o Case reports show effectiveness when
• traditional and invasive techniques fail
• o 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
• o Appears to have a synergistic effect with opioids
 Miscellaneous Anti-Adjuvant Drugs
o Pamidronate (Aredia)

o Zoledronic acid (Zometa)

o Strontium-89 (Metastron)
0 Calcitonin (Calcimar) Not in cancer ? arthritis
0 Capsaicin (Zostrix) scheduled in neuropathic pain
o Cannabinoid (Marinol)
 PHYSICAL MEASURES

• Exercises :Graded exercise program prevents joint stiffness, muscle atrophy and
contractures

• Superficial heating modalities:

a. Conductive -therapy. hot packs, paraffin baths.
b. Convective
c. Radiant.
• ULTRASOUND: for deep pain Cont…
 ACCUPUNCTURE:

• Useful adjunct for patients with chronic musculoskeletal disorders and

headaches.
• Technique - insertion of needles in discrete anatomically defined points called
“MERIDIANS”
 TRANSCUTANEOUS ELECTRICAL NERVE STIMULATION (TENS)

o Used widely in chronic pain

o 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.
 PHYSICAL MEASURES
• Ice packs
• Chiropractic/osteopathic manipulations
• Massage
• Yoga
• Topical agents (Ben Gay/Icy Hot - with menthol, salicylates, Capcaicin)
• Local injections (steroids, lidocaine)
• Glucosamine shown to help with osteoarthritis
Cont…

• Homeopathies/flower essences - for relaxation, visceral pain

• Herbals/supplements - glucosamine shown to be useful in
osteoarthritis, certain herbs like chamomile useful for colicky 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%
 Psychological methods
• Integral part of multidisciplinary approach to pain management.
1. Self management techniques – cognitive methods, relaxation, biofeedback.

2. Operant techniques.

3. Group therapy.
 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.
CONT…
Cont…

o Biofeedback - provides biophysiological feedback to patient about some bodily

process the patient is unaware of (e.g.,forehead muscle tension).
o Relaxation - systematic relaxation of the large muscle groups.

o Hypnosis - relaxation + suggestion + distraction + altering the meaning of pain

 Cont…
0 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.
INVASIVE TECHNIQUES
 ROLE OF INVASIVE PROCEDURES

• Intractable pain*
• Intractable side effects*
* Symptoms that persists despite carefully individualized patient
management
 Cont…

• Somatic nerve blocks:

- Trigeminal nerve blocks

- Cervical,thoracic,lumbar paravertebral blocks

- Facet blocks

- Trans sacral nerve blocks etc.

 Cont…

Sympathetic blocks:

• Stellate ganlion block Celiac plexus block

• Thoracic,lumbar sympathetic chain block etc

 Cont…
o SELECTION OF BLOCK:

• Depends on

- Location of pain

- Its presumed mechanism

- Skills of treating physician.

o L.A 's can be applied locally,at peripheral nerve, somatic plexus, sympathetic ganglia

nerve root, centrally in neuraxis.

 Stellate Ganglion Block

CELIAC PLEXUS BLOCK

 EPIDURAL INJECTIONS:

- Lumbar interlaminar epidural injections

- Fluoroscopic injections

- Transforaminal injections

- Radiofrequency rhizotomy
 CONT…

o SPINAL INJECTIONS:

o 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.
 Spinal Cord Stimulation
o Also called dorsal column stimulation.
o Produces analgesia by directly stimulating large A beta fibers in
dorsal columns of the spinal cord.

o Mechanism - activation of descending modulating systems and

inhibition of sympathetic outflow.
□ Indications: Cont…
- 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.
 INTRACEREBRAL STIMULATION

□ Deep brain stimulation may be used for intractable cancer pain and
rarely for intractable neuropathic pain of nonmalignant origin.
- Electrodes are implanted stereo-tactically into periaqueductal and
periventricular gray areas for nociceptive pain.
- Complications: intracranial hemorrhage and infection.
••Pain is unnecessary.
Effective Conclusion
tools patients.
are available to help doctors evaluate
pain in their 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
•Addiction aggressively.
rarelypain.
occurs.Tolerance
Trust yourandpatient when
they report
dependence can occur. physical
• Plan focus
and youon will succeed.
relieving painTake
at the
your initiative
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Your
patients depend on it.