Pain%20Management%20In%20Palliative%20Care

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Pain Management In Palliative Care
Mike Harlos MD, CCFP, FCFP Professor and Section
Head, Palliative Medicine, University of
Manitoba Medical Director, WRHA Palliative
Care Medical Director, Pediatric Symptom
Management Service
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Pain

• An unpleasant sensory and emotional experience
  associated with actual or potential tissue
  damage, or described in terms of such damage.

International Association for the Study of Pain
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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.

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Approach To Pain Control in Palliative Care

• Thorough assessment by skilled and knowledgeable
  clinician
• History
• Physical Examination
• Pause here - discuss with patient/family the
  goals of care, hopes, expectations, anticipated
  course of illness. This will influence
  consideration of investigations and interventions
• Investigations X-Ray, CT, MRI, etc - if they
  will affect approach to care
• Treatments pharmacological and
  non-pharmacological interventional analgesia
  (e.g.. Spinal)
• Ongoing reassessment and review of options,
  goals, expectations, etc.

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TYPES OF PAIN
NEUROPATHIC
NOCICEPTIVE
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Somatic Pain

• Aching, often constant
• May be dull or sharp
• Often worse with movement
• Well localized
• Eg/
• Bone soft tissue
• chest wall

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Special Considerations in Bone Pain

• Spinal cord compression in vertebral mets
• Pain earliest feature
• Risk of pathological fracture
• Indications for prophylactic surgery in
  large, weight-bearing bones
• Cortical Lesions
• Destruction of gt 50 of the cortical width
• Axial length of lesion gt diameter of the bonegt 2
  3 cm lesion
• Medullary lesions
• Lesion gt 50 of the medulla
• Pain unrelieved by radiotherapy

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Visceral Pain

• Constant or crampy
• Aching
• Poorly localized
• Referred
• Eg/
• CA pancreas
• Liver capsule distension
• Bowel obstruction

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FEATURES OF NEUROPATHIC PAIN
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
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PainAssessment
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• Describing pain only in terms of its intensity
  is like describing music only in terms of its
  loudness

von Baeyer CL Pain Research and Management 11(3)
2006 p.157-162
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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?

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Example Of A Numbered Scale
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Medication(s) Taken

• Dose
• Route
• Frequency
• Duration
• Efficacy
• Adverse effects

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Physical Exam In Pain Assessment Inspection /
Observation
You can observe a lot just by watching Yogi
Berra

• 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

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Physical Exam In Pain Assessment Palpation

• Localized tenderness to pressure or percussion
• Fullness / mass
• Induration / warmth

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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

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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.

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PainTreatment
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Non-Pharmacological Pain Management

• Acupuncture
• Cognitive/behavioral therapy
• Meditation/relaxation
• Guided imagery
• TENS
• Therapeutic massage
• Others

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W.H.O. ANALGESIC LADDER
Strong opioid
/- adjuvant
Weak opioid
/- adjuvant
Pain persists or increases
Non-opioid
/- adjuvant
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STRONG OPIOIDS

• most commonly use
• morphine
• Hydromorphone (Dilaudid )
• transdermal fentanyl (Duragesic)
• oxycodone
• Methadone
• DO NOT use meperidine (Demerolâ) long-term
• active metabolite normeperidine seizures

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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 titrate

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Drug Drug Approximate Equipotency with Morphine(MorphineDrug)
Hydromorphone Hydromorphone 51
Oxycodone Oxycodone 1.51 to 21
Codeine Codeine 112
Methadone Daily Morphine Dose
Methadone 30 90 mg 3.71
Methadone 90 300 mg 7.751
Methadone gt 300 mg 12.751
Fentanyl Fentanyl 801 to 1001 (for subcutaneous dosing of each)
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TITRATING OPIOIDS

• dose increase depends on the situation
• dose by 25 - 100

EXAMPLE (doses in mg q4h)
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http//palliative.info
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http//palliative.info
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TOLERANCE
PSYCHOLOGICAL DEPENDENCE / ADDICTION
PHYSICAL DEPENDENCE
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TOLERANCE
A normal physiological phenomenon in which
increasing doses are required to produce the same
effect
Inturrisi C, Hanks G. Oxford Textbook of
Palliative Medicine 1993 Chapter 4.2.3
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PHYSICAL DEPENDENCE
A normal physiological phenomenon in which a
withdrawal syndrome occurs when an opioid is
abruptly discontinued or an opioid antagonist is
administered
Inturrisi C, Hanks G. Oxford Textbook of
Palliative Medicine 1993 Chapter 4.2.3
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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
Inturrisi C, Hanks G. Oxford Textbook of
Palliative Medicine 1993 Chapter 4.2.3
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Changing Route Of Administration In Chronic
Opioid Dosing
po / sublingual / rectal routes SQ / IV /
IM routes
reduce by ½
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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
• with short-acting opioid preparation

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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
• Neurotoxicity (OIN) delirium, myoclonus
  seizures

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Spectrum of Opioid-Induced Neurotoxicity
Seizures,Death
Opioidtolerance
Mild myoclonus(eg. with sleeping)
Severe myoclonus
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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

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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.

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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)

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CORTICOSTEROIDS AS ADJUVANTS

• inflammation
• edema
• spontaneous nerve depolarization

tumor mass effects
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CORTICOSTEROIDS ADVERSE EFFECTS
IMMEDIATE LONG-TERM
Psychiatric Hyperglycemia risk of GI bleed gastritis aggravation of existing lesion (ulcer, tumor) Immunosuppression Proximal myopathy often lt 15 days Cushings syndrome Osteoporosis Aseptic / avascular necrosis of bone
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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

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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
• Nerve blocks

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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

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Incident Pain
Pain occurring as a direct and immediate
consequence of a movement or activity
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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
• Catheterization

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Having a steady level of enough opioid to treat
the peaks of incident pain...
...would result in excessive dosing for the
periods between incidents
Pain
Time
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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
100 µg fentanyl
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INCIDENT PAIN PROTOCOL
(see also http//palliative.info)
Step Medication (50 mg/ml) Micrograms Sublingually
1 Fentanyl 50
2 Sufentanil 25
3 Sufentanil 50
4 Sufentanil 100
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INCIDENT PAIN PROTOCOL ctd...

• fentanyl or sufentanil is administered SL 10 min.
  prior to anticipated activity
• repeat q 10min x 2 additional doses if needed
• increase to next step if 3 total doses not
  effective
• physician order required to increase to next step
  if within an hour of last dose
• the Incident Pain Protocol may be used up to q 1h
  prn