MANAGEMANT OF CANCER PAIN IN CHILDREN

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MANAGEMANT OF CANCER PAIN IN CHILDREN

• Prof. M Badr

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PHYSIOLOGY OF PAIN

• Pain is a protective mechanism for the body. It
  causes the individual to remove the painful
  stimuli, so prevent tissue damage. Nociceptors
  are the receptors of pain.
• Pain pathways
• The pain pathway includes the following
  components
• a. Peripheral receptors
• b. Neural pathways
• c. Spinal Cord mechanisms long tracts
• d. Brainstem, thalamus, cortex other areas.
• e. Descending pathways

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Pain transmission.
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• Pain Nerve Fibers
• Pain impulses are transmitted to the CNS
  through 2 types of fibers, which are
• A d fiber These are small myelinated nerve
  fibers 2-5 µm. In diameter. They conduct at
  velocity of 12-30 meter/second. A d fibers
  synapse primarily in lamina I (lamina
  marginalis).
• C fibers These are unmyelinated nerve fibers
  with a diameter of 0.4-1.2 µm. Their conduction
  velocity is 0.6-2 meter /second. Slow pain is
  claimed to be conducted via these fibers. The C
  fibers synapse in lamina II and III substantial
  gelationsa.

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Pain pathway
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Developmental Stages in Pediatric Pain
Perception
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Types of Cancer Pain

• Nociceptive
• Soft tissues.
• Bone metastasis.
• Neuropathic.
• Visceral.
• Combined.

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Cancer Pain Syndromes

• Pain in the cancer patient results from
• 1- Direct tumor involvement
• 2- Pain associated with cancer therapy
• 3- Pain unrelated to the cancer or the cancer
  therapy

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1- Direct tumor involvement

• Direct tumor involvement of bone, hollow viscera,
  or nerves is a common cause of pain in pediatric
  cancer patients.
• Pain caused by tumor occurs in 2546 of
  patients, often as a result of leukemic
  infiltration of bones or joints.
• a- Somatic pain is typically well localized
  Examples pain associated with primary or
  metastatic bone disease.

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• b- Visceral pain is poorly localized, often
  described as "deep", "squeezing" and "pressure"
  and may be associated with nausea, vomiting and
  diaphoresis, particularly when acute. It may
  result from the infiltration, compression,
  distension or stretching of thoracic and
  abdominal viscera by primary or metastatic
  tumors. Example pain associated with tumors of
  the liver primary or metastatic.
• c- Neuropathic pain results from tumor
  compression or infiltration of peripheral nerves
  or the spinal cord. Chemical- or radiation-
  induced injury also may result in this sort of
  pain.

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• 2- Pain associated with cancer therapy
• It includes pain which occurred in the
  course of, or as a result of, chemotherapy,
  surgery, or radiation therapy. Procedural pain
  occurs in approximately 40 of children. Last,
  pain caused by treatment toxicities (e.g.,
  mucositis) occurs in 4050 of children
• 3- Pain unrelated to the cancer or the cancer
  therapy.

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Mediators producing pain

• Malignant cells produce
• PGs.
• Cytokines Growth factors EGF, TGF, PDGF, and
  Endothelin 1.
• Macrophages (20-30) in malignant tumors
• TNFa.
• IL-1

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Importance of pain relief

• Elimination of stress response that has an
  influence on
• Sleep.
• Appetite and nutrition.
• Nitrogen balance.
• Cytokine cascade, towards immuno-suppression.

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Patient Assessment

• Assessment of patients pain.
• Assessment of patients psychological state.
• Assessment of patients social state.
• Assessment of patients family care giver state.

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Pain Assessment in Pediatric

• Pain assessment in children is difficult and this
  has led to the proliferation of multiplicity of
  pain assessment scales for neonates, infants and
  children. Most of these scales try to assign a
  numerical value to one of these dimensions
  cognitive, physiological, sensory, behavioral,
  and even facial expression.
• Pain can be assessed by
• 1- Self-report (what children say).
• 2- biological markers (how their bodies react),
• 3- and behavioral methods (what children do).

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1)Self-Report (e.g. face scale, graphic rating
scale.)

• Face scales
• Children are asked to indicate their pain by
  pointing to one of the faces put in a scale.
  Usually the child is trained by asking how he or
  she would feel following some minor pain and then
  a more severe pain. However, it is important to
  be sure that the scale signifies pain and not
  simple misery.

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2)Biological Measures

• Heart rate Heart rate initially decreases and
  than increases in response to short, sharp pain.
• Arterial oxygen saturation Oxygen saturation
  decreases during painful procedures.
• Stress Hormones Surgery or trauma triggers the
  release of stress hormones (corticosteroids,
  catecholamine, glucagon and growth hormone) into
  the blood with reduction in insulin levels.
• Cortisol release widely studied in infants and
  children, is not specific to pain and occurs in
  many adverse situations.

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3-Behavioral methods

• 1-Behavioral Pain Assessment Scales For Young
  Children (FLACC Scale).
• Five categories (F) Face (L) Legs (A)
  Activity (C) Cry (C)Consolability
• 2-The children's Hospital of Eastern Ontario pain
  Scale (CHEOPS)
• The scale assigns a point score to 6 categories
  of behavior

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Social and Psychological Assessment

• This form of assessment is important to define a
  successful plan for management.
• The response of the patient is highly dependant
  on his attitude to the situation (coping).
• The family members who are going to carry, and
  held responsibility for executing properly the
  treatment plan, or caregivers.

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Cancer Pain management

• Although improved, it is considered up-till now
  as an empirical treatment, hopes in the future to
  have specific antagonists to each type of
  mediator released.
• Should be considered always as an adjuvant
  treatment to anticancer therapy to improve the
  outcome and prognosis.
• Care is also paid for psychological, and
  para-neoplastic syndromes.

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Aim of Management

• To prevent pain from coming rather than to relief
  pain when it comes, this will
• provide a better quality of life.
• Better monitor the clinical state of cancer
  growth and dissemination.
• decrease the total analgesic dose.
• prevent tolerance.
• improve patients immunity and suppress stress
  response, and give a better response to
  anti-cancer therapy.

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General roles for management

• Optimization of drug therapy
• Right analgesic.
• Right dose.
• Right schedule.
• Right co-analgesic.
• Individualization for each patient.
• Opioid Rotation if there is side effects.
• Anticipation of breakthrough pain.
• Prevention of side effect.

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• Management of cancer pain can be divided
  according to causes into
• 1. Management of Procedure related pain
• This includes topical local anesthetics,
  intravenous sedation, transmucosal drug and
  nitrous oxide.
• 2. Management of Treatment related pain
• This is includes treatment of mucositis, post
  operative pain, infection.

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• 3-Management of cancer related pain
• This includes a complex mechanism which
  depend on severity of pain followed by choose
  the appropriate drugs which depend on what is
  called stepladder of WHO which divide pain into 3
  categories
• Step 1 Mild pain NSAIDs and Paracetamol are the
  drugs of choice.
• Step 2 Moderate pain where weak opioid with
  NSAIDs are used as codeine or hydrocodone
• Step 3 Severe pain strong opioid and
  intervention therapy are used morphine,
  hydromorphone, methadone, fentanyl, or
  levorphanol.

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Step ladder WHO
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Oral Analgesics

• Easier.
• Desired.
• Remember that
• Concentrations unpredictable
• Constant serum level is important to keep the
  patient not in pain.
• Higher levels of metabolites
• Higher incidence of side effects.
• Burden on the kidney More ionized.
• The oral route cannot be used in patients
• Who are unable to swallow.
• Have a bowel obstruction or.
• Have persistent nausea and vomiting.

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Analgesics are given by

• Oclock, and not when needed.
• Full clinical dose.
• In sustained release formula.
• By step ladder system.
• With an adjuvant.

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Recommended dose for mild pain for pediatrics
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Opioids

• Problem of addiction
• Presence of pain protects against addiction.
• Side effects are mainly
• Tolerance.
• Constipation.
• Nausea / vomiting.
• Sedation / dizziness.
• Rash.
• Respiratory depression.

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Weak OpioidsSecond Step in WHO Ladder

• They can relief pain when we increase the dose
  but with significantly higher incidence of side
  effects.
• Members are
• Codeine and dihydro-codeine.
• Tramadol.
• Dextro-propoxyphene.

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Strong Opioids

• Morphine available in.
• Immediate release( 4 hourly).
• Controlled release (12-hourly).
• Sustained release (24-hour dosing).
• Oxycodone.
• Fentanyl (available in a transdermal, and
  transmucosal formulation).
• Methadone.
• Hydromorphone.
• Oxymorphone (available in a rectal formulation).
• Meperidine is not used.

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Principles of Dosing

• Opioid naive patients should start on weak
  opioids.
• An immediate release formulae are only used for
  dose titration, and break through pain.
• Maintenance should be with sustained release
  formulae.
• Switching opioids is done with half or 2/3 of
  equi-analgesic doses.

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Transdermal Route

• Transdermal drug systems deliver a drug to the
  skin surface at a rate less than the maximum rate
  of transport through the skin .
• This enables to control the drug to remain within
  the delivery system and not within the skin.
• The stratum corium is difficult to penetrate.
• Stores a drug depot that prolong drug action.

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Transdermal Therapy System TTS
Drug Reservoir Alcohol is added
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Minimizing Side Effects

• Constipation
• Around the Oclock laxatives.
• Should be monitored as pain.
• Nausea and vomiting
• Secondary causes should be excluded.
• Anti-emetics.
• Sedation
• Psychostimulants.
• Opioid rotation may improve side effects

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Adjuvant Drugs

• Their presence is crucial in the success of
  management.
• They can promote sleep, relief anxiety,
  potentiate pain relief, smooth side effects.

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Drugs for Bone Pain

• Nonsteroidal Anti-Inflammatory Drugs
• Corticosteroids
• Bisphosphonates
• Pamidronate, alendronate)
• Calcitonin
• Radiopharmaceuticals
• Strontium-89.

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Drugs Used for Bowel Obstruction

• Anticholinergics
• Scopolamine reduces peristalsis and secretions,
  subjective reports of analgesic effects
• Octreotidereduces peristalsis and secretions,
  subjective reports of analgesic effects
• Corticosteroidssubjective reports of analgesic
  effects

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Conclusion

• Cancer Pain can greatly influence patients
  prognosis and should be managed early, and
  specifically.
• Drug therapy is still the corner stone in cancer
  pain management.
• If properly scheduled, drug therapy can achieve
  90 success.

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• No injectable forms are used for maintenance
  except through a pump.
• Sustained release formulae is the role.
• Oral formulations generally have more side
  effects particularly with kidney affection.
• Recently introduced fentanyl patch, and oxycodone
  got their success from the less side effects they
  produced.