Chronic cancer pain Flashcards
Acute pain
Transmitted via Aδ fibres (fast)
Examples:
- headache
- post operative pain
- post injury pain
Chronic pain
Transmitted via C fibres (slow)
Examples:
- cancer pain
- lower back pain
- osteoarthritic pain
Components of a pain assessment
A focused patient history
A thorough and focused physical examination and documentation of findings
Additional medical diagnostic procedures
The use of standardised pain assessment tools
Pain assessment tools
Numeric
Descriptive
Visual analogue score
Faces
Patients’ barriers to pain and assessment and treatment
Reluctance to report pain
- might indicate serious problem
- trying to be a ‘good’ patient
- fear of diagnostic tests/ procedures
Reluctance to take medication
- fear of addiction
- worries about side effects
Language, previous experiences etc
HCP’s barriers to pain assessment and treatment
Reluctance to prescribe pain medication
- fear of addiction
- worries about side effects
- concern that attention may encourage medication seeking behaviour
Inadequate knowledge and experience
Failure to routinely assess and document
Nociceptive pain
Nociceptor stimulation by noxious stimuli
- chemical, mechanical or thermal
Further subdivided into somatic and visceral
Neuropathic pain
Pathological changes in, or damage to, the CNS or PNS
Arises from neural tissue
Clinical descriptions variable
- continuous ‘burning’ ‘aching’
- spontaneous ‘lancinating’ ‘electric’
Associations
- allodynia
- hyperalgesia
- hyperpathia
Somatic pain
Arises from bone, muscle, cutaneous and connective tissue
Localised
Typically clinically described as throbbing or stabbing
Visceral pain
Arises from internal organs
Generalised/ diffuse
Clinically, typically described as cramping or gnawing
Somatic pain characteristics
Origin: stimulation of nociceptors
Nerve function: normal
Location of injury: tissue
Description: throbbing, sharp, stabbing
Abnormal sensations: none
Responds to opioid analgesic: tends to respond
Examples: arthritis, metastatic bone pain
Visceral pain characteristics
Origin: stimulation of nociceptors
Nerve function: normal
Location of injury: abdominal, thoracic or pelvic viscera
Description: gnawing, cramping
Abnormal sensations: none
Response to opioid analgesic: tends to respond
Examples: cholecystitis, pancreatitis
Neuropathic pain characteristics
Origin: nerve damage
Nerve function: abnormal
Location of injury: central/ peripheral nervous system
Description: burning, shooting, tingling, aching
Abnormal sensations: common
Response to opioid analgesic: less response
Examples: post herpetic neuralgia, diabetic distal sensory peripheral neuropathy, phantom limb pain
Relative potency compared to oral morphine
Alfentanil x30
Buprenorphine x100
Codeine x0.1
Diamorphine x3
Fentanyl x100
Morphine sulfate
Oxycodone x1.5-2
Tramadol x0.2
Oral morphine use
Moderate to severe pain
Help breathlessness
Quick acting, works after about 30 minutes
