243 Pain Flashcards
Describe chronic pain
Pain lasting over 3-6 months
Pain that occurs after tissue healing has taken place
Pain persisting after the course of acute disease
E.gs arthritis, cancer, fibromyalgia
Describe acute pain
Pain that lasts less than 3-6 months
May be postoperative pain or result from acute injury
What are the three main classes of pain?
Nociceptive
Neuropathic
Inflammatory
What is the Nociceptive classification of pain?
Normal response to noxius insult (painful stimuli) or injury of tissues, skin, muscle joints, tendons
Nociceptors react in response to something
Somatic (cells) usually localised eg. Hitting finger
Visceral: organs and smooth muscle, often referred eg. Heart pain causing pain in arm
What is post herpetic neuralgia?
When pain persists in someone that’s already HAD shingles (herpes zoster)
Tingly and uncomfortable pain.
Part of neuropathic pain classification.
What is inflammatory pain?
Results from activation of the Nociceptive pain pathway by a variety of mediators released in tissue inflammation
Pro-inflammatory cytokines eg IL1 alpha, IL1 beta, IL6, TNF a
Examples are rheumatoid arthritis, appendicitis, inflammatory bowel disease, herpes zoster (shingles- virus In nerve endings )
What are the 5 types of pain/ condition in the WHO classification of MuscoSkeletal disorders?
Inflammatory rheumatoid diseases eg RA Osteoporosis Osteoarthritis Soft tissue periarticular disorders Back pain
What are the types of pain that are hard to classify?
Cancer pain
Fibromyalgia
Migraine & other primary headaches
What causes Fibromyalgia?
The exact cause is unknown
What happens in people with fibromyalgia?
Disturbed pain messages
Low levels of hormones- dopamine, noradrenaline, serotonin
Sleep problems
Pain in upper back and around collar bones mostly
What areas does the pain effect with fibromyalgia?
Pain in muscles and fibrous tissues, such as from tendons and Ligaments
NB: it does NOT affect the joints (not arthritis)
What are the pharmacological options for treatment of fibromyalgia?
Analgesics
Antidepressants
Drugs currently being looked at: Pramipexole, Pregabalin
Any non-pharmacological options for treating Fibromyalgia?
Balneotherapy (Hot Pool)
Cognitive behavioural therapy (CBT)
Massages
First line treatment for Breakthrough pain?
ORAMORPH
An immediate release morphine
Consider if:
Intolerance to morphone
Unable to swallow
Rapid onset and short duration of BTP
What is the usual dose for breakthrough pain?
Between 1/6th -1/10th of the starting dose
Depends what is best for patient
Also used in Breakthrough pain but NOT first line?
Fentanyl products
Eg Actiq, abstral, Effentora
Consider if:
Intolerance to morphone
Unable to swallow
Rapid onset and short duration of BTP
Five types of Pain rating scales/ questionnaires you can think of?
Verbal rating scale Numerical rating scale Visual analogue score Visual recognition (Faces ) McGill pain Questionaire
What route of administration of analgesics should be used wherever possible?
ORAL administration
What’s the standardized dosage of pain medication such as stron opioids?
There isn’t one!!
Dosing of pain medication should be adapted to the individual
Every patient will respond differently
The correct dose is one that allows adequate relief of pain for that patient
Analgesics should be prescribed with a constant concern for detail. What does this mean?
The regularity of analgesic administration is crucial for the adequate treatment of pain.
Once distribution of medication over a day is established, it is good to provide a written personal program to the patient.
Patient family and medical staff will all have info on when to administer medicines
What is the WHO analgesic ladder ? (From 1-3)
1) paracetamol +/- NSAID
2) Step 1 + weak opioid
3) step 1+ strong opioid
What’s the WFSA analgesic ladder for ACUTE pain?
1) strong opioid by injection + local anaesthetic
2) opioids by mouth + paracetamol +/- NSAID
3) Paracetamol +/- NSAID
Step 2 of the WHO ladder is paracetamol + weak opioid. What weak opioid could be used?
Regular co-codamol
Dihydrocodeine
Step 3 of the WHO ladder involves Paracetamol + strong opioid. What strong opioid could be used?
Regular morphine
The newer version of the WHO pain ladder now includes some new additions.
What new additions are there to step 3?
(Strong opioids)
Methadone
Transdermal patch
The newer version of the WHO pain ladder now includes some new additions.
What does STEP 4 involve? (ADVANCED interventions)
Nerve block Epidurals PCA pump Neurolytic Block therapy Spinal stimulators
What is an NNT?
The higher the NNT number, the LESS effective the drug is at pain relief.
NNT= 1, everyone gets pain relief, good drug
NNT= 16, only 1 in 16 patients get pain relief from this drug
What analgesics have LOW NNTs? (Therefore v effective)?
Diclofenac 100mg- but CV risks now! (NNT1.9)
Paracetamol 1g + Codeine 60 mg in combo (NNT 2.2)
Naproxen 440mg (NNT 2.3)
Oxycodone IR 15mg (NNT 2.3)
Would you consider codeine as a monotherapy?
No not really
NNT of codeine 60mg monotherapy= 16.7!
Paracetamol + codeine = 2.2 (much better!)
Paracetamol 1g monotherapy = 3.8
Will NNT usually increase or decrease with INCREASING the dose of analgesic? (Eg tramadol?)
Decrease
This is expected; higher dose = more pain relief = lower NNT= more patients experience pain relief from this drug