Analgesic and Pain Management Flashcards
what is pain
An unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage
name the 4 different types of pain
- Nociceptive
- Inflammatory
- Neuropathic
- Mixed
what are the two types of nocipeception
C fibres and delta fibres
What happens in tissue damage
Release of inflammatory mediators (K+ H+ bradykinin, histamine, 5HT, nitric oxide
Activation of arachidonic acid pathway – production of leukotrienes and prostanoids
Activation of peripheral nociception
Modulation of primary afferents to subsequent stimulus
What is neuropathic pain
Pain originates witin the nervous system proximal to the pain receptor
What happens in neuropathic mechanisms
Alteration in ion channel expression
Ectopic and spontaneous discharge
Ephaptic conduction
Collateral sprouting at primary afferents
Sprouting of sympathetic neurones at DRG
have a hyperexitied neurone which releases excess excitatory neurotransmitters
what leads to central hypersensitivity
- Spinal reorganisation, WDR
- Wind up, glutamate and NMDA receptors
- Pain loop
name the inhibitory pathways
GABA
Opioid
Monoaminergic
Cannabinoid
what are the influences on pain experience
- age
- fear
- gender - women do better with pain
- culture
- education and understanding
- previous pain experience
how long does acute pain last for
less than 12 weeks
describe actue pain
- Nociceptive
- Primary afferent neurones
- Detection of noxious / damaging stimulus
- Information relayed to supraspinal structures
- Pain response correlates to degree of tissue inflammation
How long does chronic pain last for
longer than 12 weeks
describe chronic pain
No apparent ongoing tissue damage
Ectopic focus of neural activity
Central / peripheral sensitisation
Response to treatment less effective
Prognosis unpredictable
Often has a significant psychological component
Name some co-morbdiity that is associated with chronic pain
- difficulty sleeping
- lack of energy
- drowsiness
- concentration difficulties
- depression
- anxiety
- poor appetite
how can you measure the expression of pain
VAS Visual analogue score
VRS Verbal rating scale
Observer scoring
Likert scale
Magill Pain Questionnaire
SF36
What are the aims of treatment in pain
- Identify the source of pain
- Limit further damage
- Maintain tissue homeostasis
- To reduce pain levels
- To restore function
What are options of treatment
- exercise
- physical therapy
- medication
- intervention
- surgery
What are the psychosocial options of pain treatment
- functioning
- reassurance
- fear avoidance
- relations
- anxiety and depression
- misconception
What is the WHO pain relief ladder
- non opioid
- weak opioid
- strokg opoid
What are conventional analgesics
- Paracetamol
- NSAIDS / COX II
- Weak opioids
- Tramadol
- Strong opioids
describe paracetamol
- has little anti-inflammatory action
- moderate pain and pyrexia
- no peripheral action
How can paracetamol be administered
IV
Orally
What are the side effects of paracetamol
- liver damage in od
What is the clinical effectiveness of paracetamol
NNT 4.6
