Pain Management in Palliative Care

(1)

Pain Management In

Palliative Care

Mike Harlos MD, CCFP, FCFP

Professor and Section Head, Palliative Medicine, University of Manitoba

Medical Director, WRHA Palliative Care

(2)

Pain

An unpleasant sensory and emotional

experience associated with actual or

potential tissue damage, or described

in terms of such damage.

(3)

Clinical Terms For The Sensory

Disturbances Associated With Pain



Dysesthesia

– An unpleasant abnormal sensation,

whether spontaneous or evoked.



Allodynia

– Pain due to a stimulus which does not

normally provoke pain, such as pain caused by light

touch to the skin



Hyperalgesia

– An increased response to a stimulus

which is normally painful



Hyperesthesia

- Increased sensitivity to stimulation,

excluding the special senses. Hyperesthesia includes

both allodynia and hyperalgesia, but the more specific

terms should be used wherever they are applicable.

(4)

Approach To Pain Control in Palliative Care

1. Thorough assessment by skilled and knowledgeable

clinician

– History

– Physical Examination

2. Pause here

- discuss with patient/family the goals of care,

hopes, expectations, anticipated course of illness. This will

influence consideration of investigations and interventions

3. Investigations

– X-Ray, CT, MRI, etc - if they will affect

approach to care

4. Treatments

– pharmacological and non-pharmacological;

interventional analgesia (e.g.. Spinal)

5. Ongoing reassessment and review

of options, goals,

expectations, etc.

(5)

TYPES OF PAIN

NEUROPATHIC

NOCICEPTIVE

Deafferentation Sympathetic

Maintained

Peripheral

Somatic

• _{bones, joints}

• connective tissues

• muscles

Visceral

• Organs –

heart, liver,

pancreas, gut,

etc.

(6)

Somatic Pain

• Aching, often constant

• _{May be dull or sharp}

• Often worse with movement

• _{Well localized}

Eg/

–

Bone

& soft tissue

– chest wall

(7)

Visceral Pain

• _{Constant or crampy}

• _Aching

• Poorly localized

• _Referred

Eg/

– CA pancreas

– Liver capsule distension

– Bowel obstruction

(8)

COMPONENT

DESCRIPTORS

EXAMPLES

Steady,

Dysesthetic • Burning, Tingling_{• Constant, Aching}

• Squeezing, Itching • Allodynia • Hypersthesia • Diabetic neuropathy • Post-herpetic neuropathy Paroxysmal, Neuralgic • Stabbing • Shock-like, electric • Shooting • Lancinating • trigeminal neuralgia • may be a component of any neuropathic pain

(9)

Pain

(10)

“Describing pain only in terms of its

intensity is like describing music

only in terms of its loudness”

(11)

PAIN HISTORY



_{Description: severity, quality, location,}

temporal features, frequency, aggravating

& alleviating factors



Previous history



_{Context: social, cultural, emotional,}

spiritual factors



_Meaning

(12)

(13)

• _Dose

• _Route

• _Frequency

• _Duration

• _Efficacy

• _{Adverse effects}

Medication(s) Taken

(14)

Physical Exam In Pain Assessment

Inspection / Observation

 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}

(16)

Physical Exam In Pain Assessment

Neurological Examination

 Important in evaluating pain, due to the possibility of spinal cord compression, and nerve root or peripheral nerve lesions

 Sensory examination

– Areas of numbness / decreased sensation

– Areas of increased sensitivity, such as allodynia or hyperalgesia

 Motor (strength) exam - caution if bony metastases (may fracture)

 Deep tendon reflexes – intensity, symmetry

– Hyperreflexia and clonus: possible upper motor neuron lesion, such as spinal cord compression or cerebral metastases.

– Hyoporeflexia - possible lower motor neuron impairment, including lesions of the cauda equina of the spinal cord or leptomeningeal metastases.

 Sacral reflexes – diminished rectal tone and absent anal reflexes may indicate cauda equina involvement of by tumour

(17)

Physical Exam In Pain Assessment

Other Exam Considerations

Further areas of focus of the physical

examination are determined by the clinical

presentation.

Eg: evaluation of pleuritic chest pain would

involve a detailed respiratory and chest wall

examination.

(18)

Pain

(19)

Non-Pharmacological Pain Management



_Acupuncture



Cognitive/behavioral therapy



_{Meditation/relaxation}



_{Guided imagery}



TENS



_{Therapeutic massage}



Others…

(20)

+/- adjuvant

Non-opioid

Weak opioid

Strong opioid

Pa

in

pe

rsi

sts

or

in

cre

ase

s

By the

Clock

W.H.O. ANALGESIC LADDER

+/- adjuvant

1

2

(21)

STRONG OPIOIDS

• _{most commonly use:}

– morphine

– Hydromorphone (Dilaudid ®)

– transdermal fentanyl (Duragesic®)

– oxycodone

– Methadone

• _{DO NOT use meperidine (Demerol}



_{) long-term}

(22)

OPIOIDS and

INCOMPLETE CROSS-TOLERANCE

• _{conversion tables assume that}

tolerance to a specific opioid is

fully “crossed over” to other

opioids.

• _{cross-tolerance unpredictable,}

especially in:

– high doses

– long-term use

• divide calculated dose in ½ and

(23)

TITRATING OPIOIDS

• _{dose increase depends on the situation}

• _{dose by 25 - 100%}

(24)

(25)

(26)

(27)

TOLERANCE

PHYSICAL

DEPENDENCE

PSYCHOLOGICAL

DEPENDENCE /

ADDICTION

(28)

TOLERANCE

A normal physiological

phenomenon in which increasing

doses are required to produce

the same effect

(29)

PHYSICAL DEPENDENCE

A normal physiological

phenomenon in which a withdrawal

syndrome occurs when an opioid

is abruptly discontinued or an

opioid antagonist is administered

(30)

PSYCHOLOGICAL DEPENDENCE

and ADDICTION

A pattern of drug use characterized

by a continued craving for an opioid

which is manifest as compulsive

drug-seeking behaviour leading to

an overwhelming involvement in the

use and procurement of the drug

(31)

po / sublingual / rectal routes

SQ / IV / IM routes

reduce by ½

Changing Route Of Administration

In Chronic Opioid Dosing

(32)

Using Opioids for Breakthrough Pain

• _{Patient must feel in control, empowered}

• _{Use aggressive dose and interval}

Patient Taking Short-Acting Opioids:

• _{50 - 100% of the q4h dose, given q1h prn}

Patient Taking Long-Acting Opioids:

• _{10 - 20% of total daily dose given, q1h prn}

(33)

Opioid Side Effects



Constipation

–

need proactive laxative use



Nausea/vomiting

–

consider treating with dopamine

antagonists and/or prokinetics (metoclopramide, domperidone, prochlorperazine [Stemetil], haloperidol)



Urinary retention



Itch/rash

–

worse in children; may need low-dose naloxone infusion. May try antihistamines, however not great success



Dry mouth



Respiratory depression

–

uncommon when titrated in response to symptom



Drug interactions

(34)

(35)

Seizures, Death Opioid

tolerance

Mild myoclonus (eg. with sleeping)

Severe myoclonus Delirium Agitation Misinterpreted as Pain Opioids Increased Hyperalgesia Misinterpreted as Disease-Related Pain Opioids Increased

(36)

OIN: Treatment



_{Switch opioid (rotation) or reduce opioid}

dose; usually much lower than expected

doses of alternate opioid required… often

use prn initially



Hydration



Benzodiazepines for neuromuscular

excitation

(37)

Adjuvant Analgesics



first developed for non-analgesic indications



subsequently found to have analgesic activity in

specific pain scenarios



Common uses:

– pain poorly-responsive to opioids (eg. neuropathic

pain), or

– with intentions of lowering the total opioid dose

and thereby mitigate opioid side effects.

(38)

Adjuvants Used In Palliative Care



General / Non-specific

– corticosteroids

–

cannabinoids

(not yet commonly used for pain)



Neuropathic Pain

– gabapentin

– antidepressants

– ketamine

– topiramate

– clonidine



Bone Pain

– bisphosphonates

– (calcitonin)

(39)



inflammation



edema



spontaneous nerve depolarization



tumor

mass

effects

CORTICOSTEROIDS AS ADJUVANTS

(40)

IMMEDIATE

LONG-TERM



Psychiatric



Hyperglycemia



 risk of GI bleed



gastritis



aggravation of

existing lesion

(ulcer, tumor)



Immunosuppression



Proximal myopathy

often < 15 days



Cushing’s syndrome



Osteoporosis



Aseptic / avascular

necrosis of bone

CORTICOSTEROIDS: ADVERSE

EFFECTS

(41)

DEXAMETHASONE

• _{minimal mineralcorticoid effects}

• _{po/iv/sq/?sublingual routes}

• _{perhaps can be given once/day;}

often given more frequently

• _{If an acute course is discontinued}

within 2 wks, adrenal suppression

not likely

(42)

Treatment of Neuropathic Pain

Pharmacologic treatment

• Opioids

• Steroids

• Anticonvulsants – gabapentin, topiramate

• TCAs (for dysesthetic pain, esp. if depression)

• NMDA receptor antagonists: ketamine, methadone

• Anesthetics

Radiation therapy

Interventional treatment

• Spinal analgesia

(43)

Gabapentin



_{Common Starting Regimen}

– 300 mg hs Day 1, 300 mg bid Day2, 300

mg tid Day 3, then gradually titrate to effect

up to 1200 mg tid



Frail patients

– 100 mg hs Day 1, 100 mg bid Day 2, 100

mg tid Day 3, then gradually titrate to effect

(44)

Incident Pain

Pain occurring as a direct and

immediate consequence of a

(45)

Circumstances In Which

Incident Pain Often Occurs

• Bone metastases

• _{Neuropathic pain}

• _{Intra-abd. disease aggravated by respiration}

»

_{“incident” = breathing}

»

_{ruptured viscus, peritonitis, liver hemorrhage}

• Skin ulcer: dressing change, debridement

• Disimpaction

(46)

Time

Incident

P

ai

n

Having a steady level of enough opioid to treat

the peaks of incident pain...

...would result in

excessive dosing

for the periods

between

(47)

Fentanyl and Sufentanil



synthetic µ agonist opioids



highly lipid soluble

• transmucosal absorption; effect in approx 10 min

• rapid redistribution, including in / out of CSF; lasts

approx 1 hr.



fentanyl » 100x stronger than morphine



sufentanil » 1000x stronger than morphine

10 mg morphine

10 µg sufentanil