Pain Flashcards
What are the 3 dimension of experiencing pain?
Sensory: eg location, intensity etc
Affective: unpleasant etc
Cognitive: it might mean something bad is happening
Which spinal tract is pain conveyed in? Where does it cross over?
Spinothalamic tract/ anterolateral system
What aspect of pain does the medial spinal system convey? (including in the brain the medulla, medial thalamus, hypothalamus, limbic system and insula)
Emotional aspects of pain
What is chronic pain?
- Pain lasting longer than 3 months
- Pain persisting longer than expected period of healing or tissue damage
- May be no apparant patholohy
What are the 3 emotional problems associated with chronic pain?
Depression, anxiety, malingering/ need for secondary gain
What are the 4 classifications of pain?
Nociceptive
Neuropathic
Functional
Psychological
What is the typical quality of neuropathic pain?
Numbness Burning Tingling Pins and Needles Sharp pain
What are the psychological and physical vicious cycles of pain?
Psych:
Pain–> anger, stress, fear–> low mood–> depression–> increased pain perception–> Pain
Physical:
Pain–> activity avoidance–> deconditioning–> pain with activity
Does chronic pain prevalence increase with ageing?
Yes
What are the most common types of pain in the elderly?
- articular, leg and foot pain
- Neuropathic lesions: postherpetic neuralgia, central post-stroke pain, painful peripheral neuropathies
What kinds of pain decrease in prevalence with age?
- headaches (peak 45-50 years) • facial / dental pain
- abdominal / stomach pain
- chest pain
Is pain in older people generally over or under reported?
Under
What are some of the challenged of assessing pain in older people?
- Stoicism
- Nihilism
- Cognitive impairment, particularly memory
- Language: dysphasias
- Autonomic blunting
Does degenerative spine disease severity correlate with back pain severity/?
No
What are some examples of pain rating scales?
Visual analogue Numerical Wong-Baker Faces Verbal rating Brief pain inventory
What are 5 issues with prescribing pain meds in older people?
- Medication interactions
- Chronic disease interactions
- Altered pharacokinetics and pharmacodynamics
- Cost
- Reduced physiological reserve
What are the 3 broad issues associated with opioid use?
- Tolerance: increased doses required for the same physiological effect
- Dependence: physiological adaptation to the presence of the drug and withdrawal syndrome if the dose stops
- Addiction: Preoccupation, drug-seeking behaviours, harm, functional impairment etc
What is pseudoaddiction?
Poorly controlled pain resulting in behaviour which appears to be drug seeking
Long vs short acting medications:
- Acute pain
- Chronic pain
Short
Long
What is breakthrough pain and how do you manage it?
What is incident pain and how do you manage it?
Breakthrough pain (pain flare) is an exacerbation of chronic pain otherwise stabilised on round-the- clock analgesia. – managed with PRN analgesia when pain occurs – if frequent PRN doses are required, increase background analgesia
Incident pain occurs with, or is exacerbated by, physical activity or an event such as a wound dressing.
– managed with analgesia PRIOR to the incident
Give 3 examples of adjuvant analgesics:
Antidepressants
Anticonvulsants
Corticosteroids
What kinds of pain are TCAs useful for?
What kinds of pain are SNRIs useful for?
What kinds of pain are anticonvulsants useful for?
Tricyclic antidepressants, eg amitriptyline – neuropathic pain – fibromyalgia – low-back pain – headaches – irritable bowel syndrome
Selective serotonin and noradrenaline reuptake inhibitors
eg duloxetine, venlafaxine
– neuropathic pain esp diabetic peripheral neuropathy
– fibromyalgia
Gabapentin and Pregabalin
α2δ subunit of Ca++ channels: brain and dorsal horn
- good evidence
- neuropathic pain
- fibromyalgia
- some evidence
- low back pain with radiculopathy
- no evidence
- non-specific low back pain
Carbemazepine
• trigeminal neuralgia
If a non-verbal person presents with pain-behaviour during movement, should they have pain meds?
yes
Chronic pain management: Approach (pall care)
Treat any underlying pathology
Treat co-morbid psychiatric conditions
Screen for red flags
Refer to chronic pain service: anaesthatist, OT, physio, phycologist
NON-PHARM:
Physical therapies:
- Heat or cold
- Physical therapies – walking, stretching and strengthening or aerobic exercises.
Psychological therapies:
- Cognitive Behavioural Therapy
CAM:
- Massage
- Acupuncture
- Yoga
- Meditation and mindfulness
PHARM:
Paracetemol
NSAIDs
(codeine and tramadol not used lots)
Morphine
- renally excreted
- short acting= morphine (oral, S/C, IV)
- long acting= MS contin (oral)
Oxycodone
- Short acting= endone, oxynorm
- Long acting= oxycontin
- With naloxone, long acting= targin (need good liver function)
- renally excreted
Hydromorphone
- Short and slow release options
- Partial agonist
- Can use in renal impairment
Fentanyl
- IV, S/C, pathc, inhaled
- Can use in renal impairment
- Patch takes 12 hrs for effect but then takes 3 days for a steady state
- Safe in renal failure
Buprenorphine
- Patch
- Hepatic clearance, good in renal failure
Other: anticonvulsants, antidepressants, ketamine, nerve blocks, spinal implants
What is an example of how CBT can help someone with chronic pain?
Cognitive therapy aims to change the way the person thinks about the issue, eg:
• my pain is a reflection of serious disease
• this is the worst thing that could ever happen to me
• activity will cause more tissue damage
Behavioural therapy aims to teach the person techniques or skills to alter their behaviour, eg:
• goal setting
• paced physical activity
• pain behaviours - moaning, limping, rubbing
Can treating pain help BPSD?
Yes
What are the pain SE of gabbapentin and pregabalin and what time of day should patients take them?
Drowsiness, confusion, postural hypotension, peripheral oedema–> start at night
Opioid prescribing:
How do you start an opioid?
What dose to give in a breakthrough?
How many breakthroughs cause you to titrate basal dose?
How much do you increase the doses by?
- Start at a low dose (bd) and prescribe a short acting dose as a PRN for breakthroughs
- Breakthough give 1/10-1/6 daily dose (ie take BD dose and double and divide by 6 or 10)
- 3 breakthroughs–> increase daily dose by 10-25% (or by 2/3 of the converted PRN dose) AND also increase PRNs proportional to new daily dose
5 critical opioid SEs:
- NV
- Drowsiness
- Resp depression
- Confusion/ delirium
- Urinary retension
What is useful for bone pain, radiotherapy pain and liver capsule stretching pain?
Dexamethasone
What are the relative potencies of opioids?
(ie in mg/day)- oral morphine=1
Oral:
Codeine: 0.13
Tramadol: 0.2
Oxycodone: 1.5
Hydromorphone: 5
Sublingual:
Buprenorphine: 0.04 (mcg/day)
Transdermal:
Buprenorphine: 2 (mcg/hr)
Fentanyl: 3 (mcg/hr)
Parenteral:
Pethidine: 0.4 Oxycodone: 3 Morphine: 3 Hydromorphone: 15 Fentanyl: 0.2 (mcg/day)
Rotating opioids- when is this appropriate in chronic pain?
Rotating is useful for SEs. If non responsive to one opioid, unlikely to be responsive to another kind.
What are the principles of treating cancer pain?
- Palliative treatment of the cancer for symptomatic relief even if it won’t be curative: chemo, radio, surgery
- Anaesthetic interventions such as nerve blocks can be used
- Spinal stimulators can be implanted by neurosurg
- Consider multidisciplinary approach: nursing and physio interventions
Meds:
Use the WHO analgesic stepladder
Non-opioid+/- adjuvant–>opioid for mild to mod pain +/- non opioid +/- adjuvant–> opioid for mod to severe pain +/- non-opioid +/- adjuvant
What are the indications for use of a syringe pump?
- Patient can no longer swallow
- Persistent NV
- Dysphagia
- Persistent seizures
- Profound weakness
- Poor absorption
